Impact of an informed choice invitation on uptake of
Available from www.bmj.com
Page 1
Impact of an informed choice invitation on uptake of
RESEARCH
Impact of an informed choice invitation on uptake of
screening for diabetes in primary care (DICISION):
randomised trial
Theresa M Marteau, professor of health psychology,1 Eleanor Mann, research assistant in psychology,1
A Toby Prevost, reader in medical statistics,5 Joana C Vasconcelos, medical statistician,2 Ian Kellar, research
psychologist,2 Simon Sanderson, senior clinical research associate,2 Michael Parker, professor of bioethics
and director,3 Simon Griffin, assistant director,4 Stephen Sutton, professor of behavioural science,2
Ann Louise Kinmonth, foundation professor of general practice2
ABSTRACT
Objective To compare the effect of an invitation promoting
informed choice for screening with a standard invitation
on attendance and motivation to engage in preventive
action.
Design Randomised controlled trial.
Setting Four English general practices.
Participants 1272 people aged 40-69 years, at risk for
diabetes, identified from practice registers using a
validated risk score and invited to attend for screening.
Intervention Intervention was a previously validated
invitation to inform the decision to attend screening,
presenting diabetes as a serious potential problem, and
providing details of possible costs and benefits of
screening and treatment in text and pie charts. This was
compared with a brief, standard invitation simply
describing diabetes as a serious potential problem.
Main outcome measures The primary end point was
attendance for screening. The secondary outcome
measures were intention to make changes to lifestyle and
satisfaction with decisions made among attenders.
Results The primary end point was analysed for all 1272
participants. 55.8% (353/633) of those in the informed
choice group attended for screening, compared with
57.6% (368/639) in the standard invitation group (mean
difference −1.8%, 95% confidence interval −7.3% to
3.6%; P=0.51). Attendance was lower among the more
deprived group (most deprived third 47.5% v least
deprived third 64.3%; P<0.001). Interaction between
deprivation and effect of invitation type on attendance
was not significant. Among attenders, intention to change
behaviour was strong and unaffected by invitation type.
Conclusions Providing information to support choice did
not adversely affect attendance for screening for
diabetes. Those frommore socially deprived groupswere,
however, less likely to attend, regardless of the type of
invitation received. Further attention to invitation content
alone is unlikely to achieve equity in uptake of preventive
services.
Trial registration Current Controlled Trials ISRCTN
73125647.
INTRODUCTION
Population screening programmes are an increasingly
important component of health care. Their public
health benefits depend on the participation of most
people at risk, although each individual has low odds
of personal benefit.1 Response rates to invitations to
attend formedical screening varyby condition and cul-
ture and are notably lower among socially deprived
groups.2 Invitations are traditionally brief and aim to
achieve high attendance rates. They most often pro-
vide information about the prevalence and severity of
the disease to be screened for, and rarely describe the
absolute chances of individual benefit or harms.3 Pol-
icy in the United Kingdom and elsewhere now advo-
cates that participation should reflect “informed
choice,” which can be defined as individual choices
informed by the nature and frequency of individual
benefits and harms of screening and actions consistent
with participants’ values.4 This differs from informed
consent by its emphasis on choices that are congruent
with individuals’ values.5
This policy change is not yet evident in the content of
invitations people routinely receive to participate in
screening programmes. This may reflect concern that
people reading information about the limited indivi-
dual benefits and possible harms of screening will feel
less positive about screening and not attend.6 7
A particular concern is that providing information to
support individual choice might have a differential
effect on attendance across social groups, resulting in
even lower uptake amongmore socially deprived peo-
ple, an example of the “inverse care law.”8 Social depri-
vation is associated with an orientation more towards
the present than the future.9 Information that the ben-
efits of screening through early diagnosis of disease
accrue in the future while the harms and burdens of
screening and preventive treatment are more
1King’s College London, Psychology
Department (at Guy’s), Health
Psychology Section, Psychology
and Genetics Research Group,
Guy’s Campus, London SE1 9RT
2University of Cambridge
Department of Public Health and
Primary Care, Cambridge
3The Ethox Centre, Division of
Public Health and Primary Health
Care, University of Oxford
4MRC Epidemiology Unit, Institute
of Metabolic Science, Box 285,
Addenbrooke’s Hospital,
Cambridge CB2 0QQ
5King’s College London,
Department of Primary Care and
Public Health Sciences, Guy’s
Campus, London SE1 3QD
Correspondence to: T M Marteau
theresa.marteau@kcl.ac.uk
Cite this as: BMJ 2010;340:c2138
doi:10.1136/bmj.c2138
BMJ | ONLINE FIRST | bmj.com page 1 of 7
Impact of an informed choice invitation on uptake of
screening for diabetes in primary care (DICISION):
randomised trial
Theresa M Marteau, professor of health psychology,1 Eleanor Mann, research assistant in psychology,1
A Toby Prevost, reader in medical statistics,5 Joana C Vasconcelos, medical statistician,2 Ian Kellar, research
psychologist,2 Simon Sanderson, senior clinical research associate,2 Michael Parker, professor of bioethics
and director,3 Simon Griffin, assistant director,4 Stephen Sutton, professor of behavioural science,2
Ann Louise Kinmonth, foundation professor of general practice2
ABSTRACT
Objective To compare the effect of an invitation promoting
informed choice for screening with a standard invitation
on attendance and motivation to engage in preventive
action.
Design Randomised controlled trial.
Setting Four English general practices.
Participants 1272 people aged 40-69 years, at risk for
diabetes, identified from practice registers using a
validated risk score and invited to attend for screening.
Intervention Intervention was a previously validated
invitation to inform the decision to attend screening,
presenting diabetes as a serious potential problem, and
providing details of possible costs and benefits of
screening and treatment in text and pie charts. This was
compared with a brief, standard invitation simply
describing diabetes as a serious potential problem.
Main outcome measures The primary end point was
attendance for screening. The secondary outcome
measures were intention to make changes to lifestyle and
satisfaction with decisions made among attenders.
Results The primary end point was analysed for all 1272
participants. 55.8% (353/633) of those in the informed
choice group attended for screening, compared with
57.6% (368/639) in the standard invitation group (mean
difference −1.8%, 95% confidence interval −7.3% to
3.6%; P=0.51). Attendance was lower among the more
deprived group (most deprived third 47.5% v least
deprived third 64.3%; P<0.001). Interaction between
deprivation and effect of invitation type on attendance
was not significant. Among attenders, intention to change
behaviour was strong and unaffected by invitation type.
Conclusions Providing information to support choice did
not adversely affect attendance for screening for
diabetes. Those frommore socially deprived groupswere,
however, less likely to attend, regardless of the type of
invitation received. Further attention to invitation content
alone is unlikely to achieve equity in uptake of preventive
services.
Trial registration Current Controlled Trials ISRCTN
73125647.
INTRODUCTION
Population screening programmes are an increasingly
important component of health care. Their public
health benefits depend on the participation of most
people at risk, although each individual has low odds
of personal benefit.1 Response rates to invitations to
attend formedical screening varyby condition and cul-
ture and are notably lower among socially deprived
groups.2 Invitations are traditionally brief and aim to
achieve high attendance rates. They most often pro-
vide information about the prevalence and severity of
the disease to be screened for, and rarely describe the
absolute chances of individual benefit or harms.3 Pol-
icy in the United Kingdom and elsewhere now advo-
cates that participation should reflect “informed
choice,” which can be defined as individual choices
informed by the nature and frequency of individual
benefits and harms of screening and actions consistent
with participants’ values.4 This differs from informed
consent by its emphasis on choices that are congruent
with individuals’ values.5
This policy change is not yet evident in the content of
invitations people routinely receive to participate in
screening programmes. This may reflect concern that
people reading information about the limited indivi-
dual benefits and possible harms of screening will feel
less positive about screening and not attend.6 7
A particular concern is that providing information to
support individual choice might have a differential
effect on attendance across social groups, resulting in
even lower uptake amongmore socially deprived peo-
ple, an example of the “inverse care law.”8 Social depri-
vation is associated with an orientation more towards
the present than the future.9 Information that the ben-
efits of screening through early diagnosis of disease
accrue in the future while the harms and burdens of
screening and preventive treatment are more
1King’s College London, Psychology
Department (at Guy’s), Health
Psychology Section, Psychology
and Genetics Research Group,
Guy’s Campus, London SE1 9RT
2University of Cambridge
Department of Public Health and
Primary Care, Cambridge
3The Ethox Centre, Division of
Public Health and Primary Health
Care, University of Oxford
4MRC Epidemiology Unit, Institute
of Metabolic Science, Box 285,
Addenbrooke’s Hospital,
Cambridge CB2 0QQ
5King’s College London,
Department of Primary Care and
Public Health Sciences, Guy’s
Campus, London SE1 3QD
Correspondence to: T M Marteau
theresa.marteau@kcl.ac.uk
Cite this as: BMJ 2010;340:c2138
doi:10.1136/bmj.c2138
BMJ | ONLINE FIRST | bmj.com page 1 of 7
Page 2
immediate may thus reduce attendance, particularly
among more socially deprived groups.10 This would
include more of those at highest risk of disease for
whom the benefits of screening might be greatest,11
including those at risk of type 2 diabetes, a common,
serious condition that can remain undiagnosed until
complications occur.12 The adverse consequences of
screening are likely to be limited13 and intensive treat-
ment of screen detected patients is likely to be
beneficial.14
Screening for type 2 diabetes and cardiovascular risk
provides examples of situations where change in beha-
viour is an important component of preventive action
and for which population based screening pro-
grammes for people at risk are now being proposed
and implemented.15 16 The evaluation of screening
invitations therefore needs to include assessment of
effects on motivation to change behaviour if diabetes
were diagnosed.
We tested three hypotheses when comparing the
informed choice invitation with a standard invitation.
Firstly, that attendance at screening for diabetes would
be lower after receipt of an informed choice invitation.
Secondly, that an interaction exists between the type of
invitation and social deprivation, such that attendance
would be lower among those from more socially
deprived groups. Thirdly, that among those who
attend for screening, intentions to change behaviour
to reduce the risk of complications, if diabetes were
subsequently diagnosed, would be stronger after an
informed choice invitation.
METHODS
More details of the trial methods can be found in the
published protocol.17 We recruited participants from
four practices based in the English counties of Cam-
bridgeshire and Suffolk, each of which varies in degree
of deprivation.We assessed the level of social depriva-
tion by using the index of multiple deprivation 2007,
which is based on UK postcodes. One practice was
from the least deprived postcode fifth, one from the
middle fifth, and two from the most deprived fifth.
We identified potentially eligible participants from
practice registers using aMIQUEST search for routine
data, which was used to calculate diabetes risk scores
for all adults aged 40-69 without known type 2 dia-
betes. MIQUEST is the National Health Service
licensed softwareused to extract information fromgen-
eral practicemedical records. The validated score used
age, sex, body mass index, and prescribed oral anti-
hypertensive and steroid drugs.12
No standard approach is used to select groups for
screening. Systematic reviews and modelling studies
suggest that restricting screening to those at high risk,
as we have done, might be the most cost effective
approach.18 We randomly sampled household clusters
in the top 25% of the risk score distribution to generate
the 1500people approached for the study.Thepractice
in the most deprived area provided data only on body
mass index, which we used to identify 407 people at
high risk. High body mass index (top fourth) is a
good proxy measure of diabetes risk.12 We subse-
quently excluded 43 people with known diabetes
who were pregnant, breast feeding, psychotic, or had
a life threatening illness. The remainder were sent let-
ters by their general practitioner asking them to return
a reply paid opt-out form to their practice within
28 days if they did not wish to receive an invitation
for practice based screening. Overall, 183 people
optedout (183/1500; 12.2%) andwe excluded a further
twobecause consent letterswere returnedundelivered.
Those who opted out were older than those who parti-
cipated, but similar in terms of deprivation and sex.
Randomisation
We randomly assigned 1272 participants to receive
one of two invitations to screening: an extended invita-
tion designed to facilitate informed choice, or a short,
standard invitation. Members from the same house-
hold were assigned to receive the same invitation
type (mean cluster size 1.14). Randomisation was
done at once for all participants in each practice and
was undertaken by the study statistician from a central
site. For each practice separately, allocations were gen-
erated simultaneously in a batch by random numbers
using Excel spreadsheet software, stratifying by num-
ber of participants in the household.
We cluster randomised 281 people with at least one
other participant from the same household. Clinical
and trial staff taking measurements and entering data
were unaware of the study arm to which participants
hadbeen assigned. Fifty six participants did not receive
an invitation: 53 were not sent an invitation and three
Allocated to receive
standard invitation (n=639)
Allocated to receive informed
choice invitation (n=633)
Sent invitation (n=618)Sent invitation (n=601)
Received invitation (n=617)Received invitation (n=599)
Sample at high risk of type 2 diabetes (n=1500)
Randomised (n=1272)
Excluded (n=228):
Criteria not met (n=43)
Opted out (n=183)
Opt-out form undelivered (n=2)
Invitation not sent (n=32):
Died (n=1)
Record unavailable (n=3)
Left practice (n=13)
Unknown (n=15)
Attended screening appointment (n=353):
Completed questionnaire (n=332)
Did not consent (n=19)
Ineligible (n=2)
Attended screening appointment (n=368):
Completed questionnaire (n=347)
Did not consent (n=18)
Ineligible (n=2)
Questionnaire missing (n=1)
Invitation returned undelivered (n=2) Invitation returned undelivered (n=1)
Invitation not sent (n=21):
Died (n=3)
Record unavailable (n=1)
Left practice (n=9)
Late exclusion by general practitioner (n=2)
Unknown (n=6)
Flow of participants through trial
RESEARCH
page 2 of 7 BMJ | ONLINE FIRST | bmj.com
among more socially deprived groups.10 This would
include more of those at highest risk of disease for
whom the benefits of screening might be greatest,11
including those at risk of type 2 diabetes, a common,
serious condition that can remain undiagnosed until
complications occur.12 The adverse consequences of
screening are likely to be limited13 and intensive treat-
ment of screen detected patients is likely to be
beneficial.14
Screening for type 2 diabetes and cardiovascular risk
provides examples of situations where change in beha-
viour is an important component of preventive action
and for which population based screening pro-
grammes for people at risk are now being proposed
and implemented.15 16 The evaluation of screening
invitations therefore needs to include assessment of
effects on motivation to change behaviour if diabetes
were diagnosed.
We tested three hypotheses when comparing the
informed choice invitation with a standard invitation.
Firstly, that attendance at screening for diabetes would
be lower after receipt of an informed choice invitation.
Secondly, that an interaction exists between the type of
invitation and social deprivation, such that attendance
would be lower among those from more socially
deprived groups. Thirdly, that among those who
attend for screening, intentions to change behaviour
to reduce the risk of complications, if diabetes were
subsequently diagnosed, would be stronger after an
informed choice invitation.
METHODS
More details of the trial methods can be found in the
published protocol.17 We recruited participants from
four practices based in the English counties of Cam-
bridgeshire and Suffolk, each of which varies in degree
of deprivation.We assessed the level of social depriva-
tion by using the index of multiple deprivation 2007,
which is based on UK postcodes. One practice was
from the least deprived postcode fifth, one from the
middle fifth, and two from the most deprived fifth.
We identified potentially eligible participants from
practice registers using aMIQUEST search for routine
data, which was used to calculate diabetes risk scores
for all adults aged 40-69 without known type 2 dia-
betes. MIQUEST is the National Health Service
licensed softwareused to extract information fromgen-
eral practicemedical records. The validated score used
age, sex, body mass index, and prescribed oral anti-
hypertensive and steroid drugs.12
No standard approach is used to select groups for
screening. Systematic reviews and modelling studies
suggest that restricting screening to those at high risk,
as we have done, might be the most cost effective
approach.18 We randomly sampled household clusters
in the top 25% of the risk score distribution to generate
the 1500people approached for the study.Thepractice
in the most deprived area provided data only on body
mass index, which we used to identify 407 people at
high risk. High body mass index (top fourth) is a
good proxy measure of diabetes risk.12 We subse-
quently excluded 43 people with known diabetes
who were pregnant, breast feeding, psychotic, or had
a life threatening illness. The remainder were sent let-
ters by their general practitioner asking them to return
a reply paid opt-out form to their practice within
28 days if they did not wish to receive an invitation
for practice based screening. Overall, 183 people
optedout (183/1500; 12.2%) andwe excluded a further
twobecause consent letterswere returnedundelivered.
Those who opted out were older than those who parti-
cipated, but similar in terms of deprivation and sex.
Randomisation
We randomly assigned 1272 participants to receive
one of two invitations to screening: an extended invita-
tion designed to facilitate informed choice, or a short,
standard invitation. Members from the same house-
hold were assigned to receive the same invitation
type (mean cluster size 1.14). Randomisation was
done at once for all participants in each practice and
was undertaken by the study statistician from a central
site. For each practice separately, allocations were gen-
erated simultaneously in a batch by random numbers
using Excel spreadsheet software, stratifying by num-
ber of participants in the household.
We cluster randomised 281 people with at least one
other participant from the same household. Clinical
and trial staff taking measurements and entering data
were unaware of the study arm to which participants
hadbeen assigned. Fifty six participants did not receive
an invitation: 53 were not sent an invitation and three
Allocated to receive
standard invitation (n=639)
Allocated to receive informed
choice invitation (n=633)
Sent invitation (n=618)Sent invitation (n=601)
Received invitation (n=617)Received invitation (n=599)
Sample at high risk of type 2 diabetes (n=1500)
Randomised (n=1272)
Excluded (n=228):
Criteria not met (n=43)
Opted out (n=183)
Opt-out form undelivered (n=2)
Invitation not sent (n=32):
Died (n=1)
Record unavailable (n=3)
Left practice (n=13)
Unknown (n=15)
Attended screening appointment (n=353):
Completed questionnaire (n=332)
Did not consent (n=19)
Ineligible (n=2)
Attended screening appointment (n=368):
Completed questionnaire (n=347)
Did not consent (n=18)
Ineligible (n=2)
Questionnaire missing (n=1)
Invitation returned undelivered (n=2) Invitation returned undelivered (n=1)
Invitation not sent (n=21):
Died (n=3)
Record unavailable (n=1)
Left practice (n=9)
Late exclusion by general practitioner (n=2)
Unknown (n=6)
Flow of participants through trial
RESEARCH
page 2 of 7 BMJ | ONLINE FIRST | bmj.com
Page 3
invitations were returned undelivered. Among those
attending for screening, consent to participate further
was obtained at screening appointments.
Standard invitation
The standard invitation reflected those commonly
used to invite people to screening for diabetes and cor-
onaryheart disease219 andwas based on examples used
in a trial and a national pilot of screening.20 21
The text stated that screening was offered because
the participant may have a higher chance of develop-
ing type 2 diabetes and that diabetes is a common,
often undiagnosed condition with serious long term
consequences (see web extra).
Informed choice invitation
The informed choice invitation contained the same
information as the standard invitation, along with
information about the risk of diabetes and its complica-
tions and the consequences of screening and treatment,
including a description of the possible harms asso-
ciated with attending for screening. The invitations
drew on best evidence andwere based on theUKGen-
eral Medical Council guidelines for consent.22 These
recommend that the following information is pre-
sented when obtaining consent for screening: the pur-
pose of screening; details of diagnosis and prognosis
with andwithout treatment; and the probability of ben-
efits and risks, presented with an emphasis on patient
choice (see web extra).
Drawing on these guidelines, the draft invitation text
was developed iteratively using “think-aloud” meth-
ods with volunteers.23 The method requires respon-
dents to verbalise their thoughts while reading the
invitation and has typically been used to examine deci-
sionmaking.24 25 In this case we used the verbal reports
to ascertain where information was not being under-
stood as intended and then refined the text by using
readability tools.26 By using a decisional balance
sheet we encouraged participants to make a choice
that reflected their values. Texts of both invitations
were comprehensible to those with reading ages of 11
and above.27
These invitations were developed and evaluated in a
study inwhich 417 adultswithout knowndiabeteswere
randomised to receive one of the invitations. Levels of
informed choice were significantly higher two weeks
after receipt of the informed choice invitation com-
pared with the standard invitation (42.9% v 11.2%; dif-
ference 31.7%, 95% confidence interval 22.5% to
40.5%)27—an outcome largely attributable to higher
levels of knowledge.
Procedure
Participants were invited by letter sent from their gen-
eral practice to attend pre-assigned screening appoint-
ments for diabetes with a research nurse at their
practice. Appointments took about 20 minutes and
were done according to a written clinical protocol.
The research nurse recorded attendance as partici-
pants arrived and sought their written consent to be
screened for diabetes. Consent was also sought to com-
plete research questionnaires at the consultation and
by post four weeks later. Thirty seven participants
(5%) declined consent to complete questionnaires and
four met the exclusion criteria (three had diagnosed
diabetes and one was judged unable to give consent).
The nurse carried out a finger prick random capillary
blood glucose test using a glucose analyser based on
the glucose dehydrogenase reaction (HemoCue B-glu-
cose analyser; HemoCue, Angelholm, Sweden). The
optimal screening test remains uncertain,18 but suitable
tests certainly include capillary blood samples in the
non-fasted state, as used in this trial.
The stability of the analyses was checked daily and
an external calibration with the quality assurance
scheme was undertaken monthly. Participants were
given their results immediately, along with brief stan-
dardised advice about healthy lifestyle. Those with
blood glucose levels of 5.5 mmol/l or more were
invited to return for a fasting capillary blood glucose
test and a full cardiovascular risk assessment, carried
out by the research nurse. The nursemeasured the fast-
ing blood glucose level, full lipid profile, height,
weight, blood pressure, and cardiovascular risk score.
Patients were given further standardised advice on life-
style, and those with fasting blood glucose levels of
6.1mmol/l ormorewere referred to their general prac-
titioner for further testing and confirmation of a diag-
nosis of diabetes. Four weeks after the appointment for
the random glucose blood test, attenders were posted a
follow-up questionnaire, which included a measure of
satisfaction with their decision.
Outcome measures
The primary outcome measure was attendance for
screening. This was recorded by the research nurse
and measured as the proportion of those invited who
attended for screening. The secondary outcome mea-
sures were intention to make changes to lifestyle and
satisfaction with decisions made.
We assessed the intention to make changes to life-
style if diabetes were subsequently diagnosed among
attenders using the arithmetic mean of three intention
Table 1 | Personal characteristics of participants randomised to receive an invitation for
screening
Variable Overall (n=1272)
Informed choice
invitation arm (n=633)
Standard invitation
arm (n=639)
% (No) women 45.5 (579) 47.6 (301) 43.5 (278)
Mean (SD) age (years) 55.5 (8.1) 55.4 (8.0) 55.6 (8.2)
Mean (SD) body mass index* 33.6 (6.0) 33.8 (6.0) 33.4 (6.0)
% (No) obese* 69.1 (817) 69.4 (413) 68.8 (404)
% (No) prescribed antihypertensives† 44.3 (383) 43.6 (187) 45.0 (196)
Mean (SD) index of multiple deprivation
2007 score‡
20.1 (10.3) 20.1 (10.0) 20.0 (10.5)
*Based on 595 participants in the informed choice arm and 587 in the standard invitation arm.
†Based on 429 participants in the informed choice arm and 436 in the standard arm from three practices,
unavailable from one practice.
‡Score combines several indicators, chosen to cover a range of economic, social, and housing issues at district
level, into a transformed index from 0-100. UK average is 21.67; eastern England regional average is 15.40. Top
10% deprived areas have average scores above 50.
RESEARCH
BMJ | ONLINE FIRST | bmj.com page 3 of 7
attending for screening, consent to participate further
was obtained at screening appointments.
Standard invitation
The standard invitation reflected those commonly
used to invite people to screening for diabetes and cor-
onaryheart disease219 andwas based on examples used
in a trial and a national pilot of screening.20 21
The text stated that screening was offered because
the participant may have a higher chance of develop-
ing type 2 diabetes and that diabetes is a common,
often undiagnosed condition with serious long term
consequences (see web extra).
Informed choice invitation
The informed choice invitation contained the same
information as the standard invitation, along with
information about the risk of diabetes and its complica-
tions and the consequences of screening and treatment,
including a description of the possible harms asso-
ciated with attending for screening. The invitations
drew on best evidence andwere based on theUKGen-
eral Medical Council guidelines for consent.22 These
recommend that the following information is pre-
sented when obtaining consent for screening: the pur-
pose of screening; details of diagnosis and prognosis
with andwithout treatment; and the probability of ben-
efits and risks, presented with an emphasis on patient
choice (see web extra).
Drawing on these guidelines, the draft invitation text
was developed iteratively using “think-aloud” meth-
ods with volunteers.23 The method requires respon-
dents to verbalise their thoughts while reading the
invitation and has typically been used to examine deci-
sionmaking.24 25 In this case we used the verbal reports
to ascertain where information was not being under-
stood as intended and then refined the text by using
readability tools.26 By using a decisional balance
sheet we encouraged participants to make a choice
that reflected their values. Texts of both invitations
were comprehensible to those with reading ages of 11
and above.27
These invitations were developed and evaluated in a
study inwhich 417 adultswithout knowndiabeteswere
randomised to receive one of the invitations. Levels of
informed choice were significantly higher two weeks
after receipt of the informed choice invitation com-
pared with the standard invitation (42.9% v 11.2%; dif-
ference 31.7%, 95% confidence interval 22.5% to
40.5%)27—an outcome largely attributable to higher
levels of knowledge.
Procedure
Participants were invited by letter sent from their gen-
eral practice to attend pre-assigned screening appoint-
ments for diabetes with a research nurse at their
practice. Appointments took about 20 minutes and
were done according to a written clinical protocol.
The research nurse recorded attendance as partici-
pants arrived and sought their written consent to be
screened for diabetes. Consent was also sought to com-
plete research questionnaires at the consultation and
by post four weeks later. Thirty seven participants
(5%) declined consent to complete questionnaires and
four met the exclusion criteria (three had diagnosed
diabetes and one was judged unable to give consent).
The nurse carried out a finger prick random capillary
blood glucose test using a glucose analyser based on
the glucose dehydrogenase reaction (HemoCue B-glu-
cose analyser; HemoCue, Angelholm, Sweden). The
optimal screening test remains uncertain,18 but suitable
tests certainly include capillary blood samples in the
non-fasted state, as used in this trial.
The stability of the analyses was checked daily and
an external calibration with the quality assurance
scheme was undertaken monthly. Participants were
given their results immediately, along with brief stan-
dardised advice about healthy lifestyle. Those with
blood glucose levels of 5.5 mmol/l or more were
invited to return for a fasting capillary blood glucose
test and a full cardiovascular risk assessment, carried
out by the research nurse. The nursemeasured the fast-
ing blood glucose level, full lipid profile, height,
weight, blood pressure, and cardiovascular risk score.
Patients were given further standardised advice on life-
style, and those with fasting blood glucose levels of
6.1mmol/l ormorewere referred to their general prac-
titioner for further testing and confirmation of a diag-
nosis of diabetes. Four weeks after the appointment for
the random glucose blood test, attenders were posted a
follow-up questionnaire, which included a measure of
satisfaction with their decision.
Outcome measures
The primary outcome measure was attendance for
screening. This was recorded by the research nurse
and measured as the proportion of those invited who
attended for screening. The secondary outcome mea-
sures were intention to make changes to lifestyle and
satisfaction with decisions made.
We assessed the intention to make changes to life-
style if diabetes were subsequently diagnosed among
attenders using the arithmetic mean of three intention
Table 1 | Personal characteristics of participants randomised to receive an invitation for
screening
Variable Overall (n=1272)
Informed choice
invitation arm (n=633)
Standard invitation
arm (n=639)
% (No) women 45.5 (579) 47.6 (301) 43.5 (278)
Mean (SD) age (years) 55.5 (8.1) 55.4 (8.0) 55.6 (8.2)
Mean (SD) body mass index* 33.6 (6.0) 33.8 (6.0) 33.4 (6.0)
% (No) obese* 69.1 (817) 69.4 (413) 68.8 (404)
% (No) prescribed antihypertensives† 44.3 (383) 43.6 (187) 45.0 (196)
Mean (SD) index of multiple deprivation
2007 score‡
20.1 (10.3) 20.1 (10.0) 20.0 (10.5)
*Based on 595 participants in the informed choice arm and 587 in the standard invitation arm.
†Based on 429 participants in the informed choice arm and 436 in the standard arm from three practices,
unavailable from one practice.
‡Score combines several indicators, chosen to cover a range of economic, social, and housing issues at district
level, into a transformed index from 0-100. UK average is 21.67; eastern England regional average is 15.40. Top
10% deprived areas have average scores above 50.
RESEARCH
BMJ | ONLINE FIRST | bmj.com page 3 of 7
Page 4
items relating to treatment adherence, reducing fat
intake, and increasing physical activity (Cronbach’s
α=0.58). Itemswere rated on a 7 point scale—for exam-
ple, “If the tests show that you definitely do have dia-
betes, how likely is it that you will increase the amount
of physical activity that you do over the next 3months?
” (1 extremely unlikely to 7 extremely likely).
Satisfaction with the decision was assessed among
attenders at four weeks by postal questionnaire using
the mean of three items (Cronbach’s α=0.92)—for
example, “How sure are you that the decision you
madewas the right one for you?” (1 not at all to 7 extre-
mely).
Statistical analysis
We determined that a sample size of 1200 participants
would provide 90% power to detect a 10% difference
between arms in the proportion attending for screen-
ing using a χ2 test at the 5% level of significance.Assum-
ing an average attendance of 65%2 gave an expectation
of 780 attenders. Full response to the initial question-
naire allowed 80% power to detect a small effect size
(0.2 standardised difference) between arms in the
intention measure using a t test at the 5% level of sig-
nificance.
We tested the first hypothesis by comparing atten-
dance rates in the informed choice and standard invita-
tion arms using the χ2 test in an intention to treat
analysis. For the second hypothesis, we used logistic
regression to test for moderating effects of social depri-
vation on the impact of invitation type on attendance
by including an interaction between arm and social
deprivation index. We carried out per protocol ana-
lyses for both these hypotheses, which excluded parti-
cipants who did not receive an invitation (n=56) and
those randomised but subsequently found to meet
exclusion criteria (n=4). For the third hypothesis we
used a t test to assess the difference between attenders’
intentions to change behaviour in the informed choice
arm compared with standard invitation arm. Using a t
test we also compared the groups for satisfaction with
the decision. All tests were two tailed and assessed at
the 5% level of significance. Further analyses that
allowed for clustering of participants in randomised
households were defined as secondary owing to the
anticipated small mean cluster size. The results of
these did not materially affect the primary results or
conclusions.
RESULTS
Recruitment to the trial started in November 2006 and
ended in July 2008.We analysed screening attendance
for all 1272 randomised participants (figure). Baseline
characteristics of the two groups were similar (table 1).
Those invited for screeningweremiddle agedmen and
women, many of whom were obese or taking anti-
hypertensive drugs. Overall, 721 (56.7%) of the rando-
mised participants attended. Compared with
attenders, non-attenders were younger, had a higher
body mass index, lived in more deprived areas, and
were less likely to be prescribed antihypertensive
drugs (table 2).
Attendance at screening for diabetes was not signifi-
cantly lower after an informed choice invitation com-
pared with a standard invitation: 56.7% v 57.6%
(difference −1.8%, 95% confidence interval −7.3% to
3.6%, P=0.51; table 3). The interaction between type
of invitation and social deprivation was not significant.
However, attendance fell with increasing deprivation
(64.3% in the lowest third v 47.5% in the highest third,
P<0.001). Per protocol analyses did not affect these
findings.
Overall, 680/721 participants (94.3%) agreed to
answer questionnaires at first attendance and 525/721
(72.8%) returned their four week follow-up question-
naires. Intention to make changes to lifestyle at first
attendance was unaffected by screening invitation:
mean intention to change behaviour if diabetes were
to be diagnosed was 5.84 (SD 1.09) in the informed
choice arm and 5.84 (SD 1.04) in the standard invita-
tion arm. Satisfaction with the decision to attend (mea-
sured in the four week follow-up questionnaire) was
high and unaffected by screening invitation: mean
6.47 (SD 0.84) in the informed choice arm and 6.48
(SD 0.87) in the standard invitation arm (difference
−0.01, 95% confidence interval −0.17 to 0.16; P=0.90).
No adverse events were recorded during the trial.
DISCUSSION
An informed choice invitation for diabetes screening
did not significantly reduce rates of attendance com-
paredwith a standard letter.No interactionwas present
between type of invitation and levels of deprivation.
Table 2 | Characteristics of non-attenders and attenders pooled over trial arms
Variable
Overall
P value*Non-attenders (n=551) Attenders (n=721)
% (No) women 42.8 (236) 47.6 (343) 0.092
Mean (SD) age (years) 53.0 (7.9) 57.4 (7.8) <0.001
Mean (SD) body mass index† 34.8 (6.3) 32.7 (5.6) <0.001
% (No) prescribed drugs‡ 46.2 (150) 53.0 (286) 0.052
% (No) prescribed antihypertensives 39.7 (129) 47.0 (254) 0.035
Mean (SD) index of multiple deprivation 2007 score 21.6 (10.6) 18.8 (9.9) <0.001
*Unpaired t test for age, body mass index, and index of multiple deprivation 2007 score; Pearson χ2 test for other variables.
†Based on 513 non-attenders and 669 attenders.
‡Based on 325 non-attenders and 540 attenders.
RESEARCH
page 4 of 7 BMJ | ONLINE FIRST | bmj.com
intake, and increasing physical activity (Cronbach’s
α=0.58). Itemswere rated on a 7 point scale—for exam-
ple, “If the tests show that you definitely do have dia-
betes, how likely is it that you will increase the amount
of physical activity that you do over the next 3months?
” (1 extremely unlikely to 7 extremely likely).
Satisfaction with the decision was assessed among
attenders at four weeks by postal questionnaire using
the mean of three items (Cronbach’s α=0.92)—for
example, “How sure are you that the decision you
madewas the right one for you?” (1 not at all to 7 extre-
mely).
Statistical analysis
We determined that a sample size of 1200 participants
would provide 90% power to detect a 10% difference
between arms in the proportion attending for screen-
ing using a χ2 test at the 5% level of significance.Assum-
ing an average attendance of 65%2 gave an expectation
of 780 attenders. Full response to the initial question-
naire allowed 80% power to detect a small effect size
(0.2 standardised difference) between arms in the
intention measure using a t test at the 5% level of sig-
nificance.
We tested the first hypothesis by comparing atten-
dance rates in the informed choice and standard invita-
tion arms using the χ2 test in an intention to treat
analysis. For the second hypothesis, we used logistic
regression to test for moderating effects of social depri-
vation on the impact of invitation type on attendance
by including an interaction between arm and social
deprivation index. We carried out per protocol ana-
lyses for both these hypotheses, which excluded parti-
cipants who did not receive an invitation (n=56) and
those randomised but subsequently found to meet
exclusion criteria (n=4). For the third hypothesis we
used a t test to assess the difference between attenders’
intentions to change behaviour in the informed choice
arm compared with standard invitation arm. Using a t
test we also compared the groups for satisfaction with
the decision. All tests were two tailed and assessed at
the 5% level of significance. Further analyses that
allowed for clustering of participants in randomised
households were defined as secondary owing to the
anticipated small mean cluster size. The results of
these did not materially affect the primary results or
conclusions.
RESULTS
Recruitment to the trial started in November 2006 and
ended in July 2008.We analysed screening attendance
for all 1272 randomised participants (figure). Baseline
characteristics of the two groups were similar (table 1).
Those invited for screeningweremiddle agedmen and
women, many of whom were obese or taking anti-
hypertensive drugs. Overall, 721 (56.7%) of the rando-
mised participants attended. Compared with
attenders, non-attenders were younger, had a higher
body mass index, lived in more deprived areas, and
were less likely to be prescribed antihypertensive
drugs (table 2).
Attendance at screening for diabetes was not signifi-
cantly lower after an informed choice invitation com-
pared with a standard invitation: 56.7% v 57.6%
(difference −1.8%, 95% confidence interval −7.3% to
3.6%, P=0.51; table 3). The interaction between type
of invitation and social deprivation was not significant.
However, attendance fell with increasing deprivation
(64.3% in the lowest third v 47.5% in the highest third,
P<0.001). Per protocol analyses did not affect these
findings.
Overall, 680/721 participants (94.3%) agreed to
answer questionnaires at first attendance and 525/721
(72.8%) returned their four week follow-up question-
naires. Intention to make changes to lifestyle at first
attendance was unaffected by screening invitation:
mean intention to change behaviour if diabetes were
to be diagnosed was 5.84 (SD 1.09) in the informed
choice arm and 5.84 (SD 1.04) in the standard invita-
tion arm. Satisfaction with the decision to attend (mea-
sured in the four week follow-up questionnaire) was
high and unaffected by screening invitation: mean
6.47 (SD 0.84) in the informed choice arm and 6.48
(SD 0.87) in the standard invitation arm (difference
−0.01, 95% confidence interval −0.17 to 0.16; P=0.90).
No adverse events were recorded during the trial.
DISCUSSION
An informed choice invitation for diabetes screening
did not significantly reduce rates of attendance com-
paredwith a standard letter.No interactionwas present
between type of invitation and levels of deprivation.
Table 2 | Characteristics of non-attenders and attenders pooled over trial arms
Variable
Overall
P value*Non-attenders (n=551) Attenders (n=721)
% (No) women 42.8 (236) 47.6 (343) 0.092
Mean (SD) age (years) 53.0 (7.9) 57.4 (7.8) <0.001
Mean (SD) body mass index† 34.8 (6.3) 32.7 (5.6) <0.001
% (No) prescribed drugs‡ 46.2 (150) 53.0 (286) 0.052
% (No) prescribed antihypertensives 39.7 (129) 47.0 (254) 0.035
Mean (SD) index of multiple deprivation 2007 score 21.6 (10.6) 18.8 (9.9) <0.001
*Unpaired t test for age, body mass index, and index of multiple deprivation 2007 score; Pearson χ2 test for other variables.
†Based on 513 non-attenders and 669 attenders.
‡Based on 325 non-attenders and 540 attenders.
RESEARCH
page 4 of 7 BMJ | ONLINE FIRST | bmj.com
Page 5
Social deprivation did, however, strongly predict
attendance. Regardless of invitation type, those from
more deprived areas were less likely to attend for
screening. Among those attending for screening, the
type of invitation did not affect their intentions to
change their behaviour to reduce risks were diabetes
subsequently diagnosed. Among both groups inten-
tions were strong. Similarly, satisfaction with the deci-
sion to attend for screening was high in both groups.
Meaning of the study results
We considered several possible explanations for our
main finding. Firstly, although the informed choice
invitation was longer and contained more information
than the standard one, recipients may have treated the
two invitations as similar. If, for example, they had
gone no further than the opening paragraph, they
would have read the same information as that pre-
sented in the standard invitation. Secondly, the provi-
sionof a prearranged screening appointmentmayhave
been regarded as an implicit recommendation for
screening, over-riding any influence of different invita-
tions. Thirdly, recipients may have gained more infor-
mation from the informed choice invitation, but this
knowledge did not affect attendance. This may be
because they perceived the harms associated with
screening to be negligible or the benefits to be very
good. In support of this, in our pilot study we found
that the informed choice invitation increased knowl-
edge about screening for diabetes but did not affect
attitudes, which were consistently positive, or inten-
tions to attend for screening.27 Other studies have
found knowledge about screening to be a weak predic-
tor of attendance and to have little or no association
with attitudes towards attending for screening.27 28 In
contrast, attitudes towards screening have been found
to be moderately strong predictors of attendance.6
The gradient in uptake with social advantage has
been observed previously.29 30 This gradient may
reflect differences in people’s attitudes or differences
in their enactment of similar positive intentions accord-
ing to their different social circumstance. In our pilot
study, individual attitudes and intentions to attend for
diabetes screening were positive regardless of social
deprivation,27 a finding supported by other studies.31
This suggests a social patterning not to intentions but
to the enactment of intentions, perhaps reflecting prac-
tical barriers to keeping appointments.
Implications for clinicians and policy makers
Taken together the evidence from this trial and other
studies suggests that providing information to support
choice does not adversely affect attendance for screen-
ing: written information can increase knowledge about
screening but this does not necessarily alter uptake or
increase the likelihood that choices are more value
consistent—that is, informed.27 28 32 33 But although we
found no evidence of harm, there was little to suggest
any quantitative benefit. The informed choice invita-
tions may have resulted in people being better
informed which, from the perspective of individual
autonomy, is a benefit. People with better knowledge
are less anxious when recalled for further tests,34 so
such invitations may be preferred, although anxiety is
not a major concern in screening for diabetes.13
Importantly, our findings raise further questions
about the equity of programmes that fail to engage
those who are more socially deprived and therefore
with lower health and life chances. Overall attendance
was low, albeit similar to a national pilot screening pro-
gramme in deprived areas in England.35 Compared
with attenders, non-attenders were not only more
likely to be from more deprived areas but also to
have a higher bodymass index, despite being younger,
and less likely to be prescribed antihypertensive drugs.
A mix of opportunistic approaches to screening (for
example, during planned reviews of drugs for hyper-
tension) combined with a range of systematic
approaches that go beyond repeated invitation letters,
however elaborate, may be most effective in creating
environments that enable people to enact their choices.
These include visiting patients at home36 and training
receptionists to telephone and talk to patients.37 The
effectiveness and appropriateness of these and other
interventions merit further consideration given the
large gap in screening uptake between the most and
least deprived groups, which is not accompanied by
evidence of a difference in motivation or preference,
both of which are uniformly high.
Strengths and limitations of the study
The trial design was rigorous for several reasons. We
defined a real world at risk population through pri-
mary care, and 87.3% of the eligible population were
randomised and participated. Both invitations were
delivered in the same way and were similar for read-
ability. Attendance was measured reliably for every
participant, and those recording it were blind to the
Table 3 | Attendance at diabetes screening after receipt of informed choice invitation or standard invitation, grouped by
social deprivation thirds. Values are percentages (numbers) unless stated otherwise
Deprivation* Overall (n=1272)
Informed choice invitation
(n=633)
Standard invitation
(n=639)
% difference in uptake
between arms
Overall 56.7 (721) 55.8 (353) 57.6 (368) −1.8 (−7.3 to 3.6); P=0.51
Lowest third (<13.7) 64.3 (272) 64.3 (133) 64.4 (139) −0.1 (−9.2 to 9.0)
Middle third (13.7-23.5) 58.5 (244) 55.8 (116) 61.2 (128) −5.5 (−14.9 to 4.0)
Highest third (>23.5) 47.5 (205) 47.7 (104) 47.2 (101) 0.5 (−8.9 to 9.9)
P=0.50 for interaction between arm and index of multiple deprivation 2007 on uptake.
*Index of multiple deprivation 2007 third.
RESEARCH
BMJ | ONLINE FIRST | bmj.com page 5 of 7
attendance. Regardless of invitation type, those from
more deprived areas were less likely to attend for
screening. Among those attending for screening, the
type of invitation did not affect their intentions to
change their behaviour to reduce risks were diabetes
subsequently diagnosed. Among both groups inten-
tions were strong. Similarly, satisfaction with the deci-
sion to attend for screening was high in both groups.
Meaning of the study results
We considered several possible explanations for our
main finding. Firstly, although the informed choice
invitation was longer and contained more information
than the standard one, recipients may have treated the
two invitations as similar. If, for example, they had
gone no further than the opening paragraph, they
would have read the same information as that pre-
sented in the standard invitation. Secondly, the provi-
sionof a prearranged screening appointmentmayhave
been regarded as an implicit recommendation for
screening, over-riding any influence of different invita-
tions. Thirdly, recipients may have gained more infor-
mation from the informed choice invitation, but this
knowledge did not affect attendance. This may be
because they perceived the harms associated with
screening to be negligible or the benefits to be very
good. In support of this, in our pilot study we found
that the informed choice invitation increased knowl-
edge about screening for diabetes but did not affect
attitudes, which were consistently positive, or inten-
tions to attend for screening.27 Other studies have
found knowledge about screening to be a weak predic-
tor of attendance and to have little or no association
with attitudes towards attending for screening.27 28 In
contrast, attitudes towards screening have been found
to be moderately strong predictors of attendance.6
The gradient in uptake with social advantage has
been observed previously.29 30 This gradient may
reflect differences in people’s attitudes or differences
in their enactment of similar positive intentions accord-
ing to their different social circumstance. In our pilot
study, individual attitudes and intentions to attend for
diabetes screening were positive regardless of social
deprivation,27 a finding supported by other studies.31
This suggests a social patterning not to intentions but
to the enactment of intentions, perhaps reflecting prac-
tical barriers to keeping appointments.
Implications for clinicians and policy makers
Taken together the evidence from this trial and other
studies suggests that providing information to support
choice does not adversely affect attendance for screen-
ing: written information can increase knowledge about
screening but this does not necessarily alter uptake or
increase the likelihood that choices are more value
consistent—that is, informed.27 28 32 33 But although we
found no evidence of harm, there was little to suggest
any quantitative benefit. The informed choice invita-
tions may have resulted in people being better
informed which, from the perspective of individual
autonomy, is a benefit. People with better knowledge
are less anxious when recalled for further tests,34 so
such invitations may be preferred, although anxiety is
not a major concern in screening for diabetes.13
Importantly, our findings raise further questions
about the equity of programmes that fail to engage
those who are more socially deprived and therefore
with lower health and life chances. Overall attendance
was low, albeit similar to a national pilot screening pro-
gramme in deprived areas in England.35 Compared
with attenders, non-attenders were not only more
likely to be from more deprived areas but also to
have a higher bodymass index, despite being younger,
and less likely to be prescribed antihypertensive drugs.
A mix of opportunistic approaches to screening (for
example, during planned reviews of drugs for hyper-
tension) combined with a range of systematic
approaches that go beyond repeated invitation letters,
however elaborate, may be most effective in creating
environments that enable people to enact their choices.
These include visiting patients at home36 and training
receptionists to telephone and talk to patients.37 The
effectiveness and appropriateness of these and other
interventions merit further consideration given the
large gap in screening uptake between the most and
least deprived groups, which is not accompanied by
evidence of a difference in motivation or preference,
both of which are uniformly high.
Strengths and limitations of the study
The trial design was rigorous for several reasons. We
defined a real world at risk population through pri-
mary care, and 87.3% of the eligible population were
randomised and participated. Both invitations were
delivered in the same way and were similar for read-
ability. Attendance was measured reliably for every
participant, and those recording it were blind to the
Table 3 | Attendance at diabetes screening after receipt of informed choice invitation or standard invitation, grouped by
social deprivation thirds. Values are percentages (numbers) unless stated otherwise
Deprivation* Overall (n=1272)
Informed choice invitation
(n=633)
Standard invitation
(n=639)
% difference in uptake
between arms
Overall 56.7 (721) 55.8 (353) 57.6 (368) −1.8 (−7.3 to 3.6); P=0.51
Lowest third (<13.7) 64.3 (272) 64.3 (133) 64.4 (139) −0.1 (−9.2 to 9.0)
Middle third (13.7-23.5) 58.5 (244) 55.8 (116) 61.2 (128) −5.5 (−14.9 to 4.0)
Highest third (>23.5) 47.5 (205) 47.7 (104) 47.2 (101) 0.5 (−8.9 to 9.9)
P=0.50 for interaction between arm and index of multiple deprivation 2007 on uptake.
*Index of multiple deprivation 2007 third.
RESEARCH
BMJ | ONLINE FIRST | bmj.com page 5 of 7
Page 6
study arm. Randomisation was at the level of the indi-
vidual, hence potential confounders were equally dis-
tributed across trial groups despite the small number of
participating practices. The results confirm the find-
ings of other trials, that informed choice invitations
have no impact on attendance. However, these trials
either failed to assess behaviour objectively32 or
recruited only those who had opted into the study33
as opposed to using an opt-out method as here, which
is preferred for minimising bias.38
The trial has several limitations. Our measure of
social deprivation was based on postcode, which was
available for all those invited. This had limited preci-
sion for individual measurement. We did not recruit
many participants in themost deprived 10% of the dis-
tribution. Despite these limitations, the measures were
sensitive enough for a strong gradient in attendance to
be shown across levels of deprivation. From an ethical
point of view it was imperative to recruit eligible parti-
cipants using an opt-out form for those not wishing to
receive an invitation for practice based screening. This
is unlikely to have influenced the generalisability of the
findings or the trial group comparisons, given the small
number who opted out and the limited information
provided comparedwith the informed choice and stan-
dard invitations to attend screening. The findings are,
however, limited in the extent to which they may be
generalised to other invitations for diabetes screening
as well as invitations for other types of screening.
Although the invitation materials were pilot tested
and found to increase knowledge27 we did not extend
the information provided using web based supple-
ments. Providing these would have allowed patients
to gain further information in a preferred format,
including the generation of a personalised risk
score.39 Additionally, web based systems allow moni-
toring of the information accessed, something not pos-
sible with paper based materials. Tailored approaches
can be more effective in generating change in
behaviour,40 but whether they more effectively facili-
tate informed choices is unknown. Furthermore, since
web access is socially patterned, its use was not appro-
priate for the current trial. In 2009, 21% of UK adults
had never used the internet,41 a group disproportio-
nately represented among the participants of particular
interest in this trial—namely, those who are socially
deprived.
Unanswered questions and future research
The generalisability of these findings to other screen-
ing programmes is unknown. The harms that can arise
from screening for diabetes were described in the invi-
tation as comprising worry and false reassurance,
which participants may not consider serious. By con-
trast, participation in other screening programmes can
entail serious physical harms from subsequent invasive
testing such as colonoscopy, or treatment such as pros-
tatectomy. The impact of increasing knowledge about
the limited individual benefit and potential harms of
treatment after screening has been studiedmost exten-
sively in the context of screening for prostate cancer.
The evidence is mixed: in one review increasing
knowledge had no impact28 but in another it reduced
uptake.42 Studies are needed to compare the impact of
presenting uncertainty about individual benefit and
harm across screening programmes with different
types and levels of harm and benefit. Our findings
also contribute to a broader debate about the most
effective and acceptable ways to communicate about
screening programmes.43 Furthermore, the study
hypotheses focused on attendance, and little informa-
tion was collected on non-attenders. Future studies
need to focus on non-attenders to understand better
their reasons for non-attendance as a basis for enabling
informed choices in this group.
Conclusions
We observed no conflict between efforts to achieve
informed choices and attendance for a population
health screening programme for diabetes. Attendance
was low, however, and socially deprived groups, who
are most vulnerable to disease, were least likely to
attend. Further attention to only the content of an invi-
tation is unlikely to achieve equity in uptake of preven-
tive services. Those designing and implementing
screening as well as other prevention programmes
need to consider how to overcome these inequities
most effectively.
We thank study participants and the staff at Bretton Medical Practice,
Peterborough; Old Fletton Surgery, Peterborough; The Rookery Medical
Centre, Newmarket; and Thorney Medical Practice, Peterborough; the
nurses who conducted the screening clinics led by Marian Bosman; the
Medical Research Council field epidemiology team; Nicola Popplewell,
Helen Morris, Kate Williams, and Rachel Crockett for their contribution to
the development of the study and the materials; and Irwin Nazareth,
Graham Watt, and Dan Mason for their contribution to discussion of the
results. ALK, TMM, SG, and SS are founder members of the National
Institute for Health Research School for Primary Care Research. ALK and
SS are National Institute of Health Research senior investigators. SG
receives support from the Department of Health National Institute for
Health Research programme grant funding scheme (RP-PG-0606-1259).
The General Practice and Primary Care Research Unit is supported by
WHAT IS ALREADY KNOWN ON THIS TOPIC
Health policies now hold that participation in screening
programmes should reflect “informed choice”
Informed choice requires the communication of the chances
of individual benefit and harm of screening, and actions
consistent with participants’ values
Such choice may deter attendance, particularly among
socially disadvantaged groups, and so increase inequalities
in health
WHAT THIS STUDY ADDS
Providing information to support choice does not adversely
affect attendance for screening
More socially deprived groups are, however, less likely to
attend regardless of type of invitation
Those designing and implementing screening and other
prevention programmes need to consider how to most
effectively overcome inequities in use of screening
RESEARCH
page 6 of 7 BMJ | ONLINE FIRST | bmj.com
vidual, hence potential confounders were equally dis-
tributed across trial groups despite the small number of
participating practices. The results confirm the find-
ings of other trials, that informed choice invitations
have no impact on attendance. However, these trials
either failed to assess behaviour objectively32 or
recruited only those who had opted into the study33
as opposed to using an opt-out method as here, which
is preferred for minimising bias.38
The trial has several limitations. Our measure of
social deprivation was based on postcode, which was
available for all those invited. This had limited preci-
sion for individual measurement. We did not recruit
many participants in themost deprived 10% of the dis-
tribution. Despite these limitations, the measures were
sensitive enough for a strong gradient in attendance to
be shown across levels of deprivation. From an ethical
point of view it was imperative to recruit eligible parti-
cipants using an opt-out form for those not wishing to
receive an invitation for practice based screening. This
is unlikely to have influenced the generalisability of the
findings or the trial group comparisons, given the small
number who opted out and the limited information
provided comparedwith the informed choice and stan-
dard invitations to attend screening. The findings are,
however, limited in the extent to which they may be
generalised to other invitations for diabetes screening
as well as invitations for other types of screening.
Although the invitation materials were pilot tested
and found to increase knowledge27 we did not extend
the information provided using web based supple-
ments. Providing these would have allowed patients
to gain further information in a preferred format,
including the generation of a personalised risk
score.39 Additionally, web based systems allow moni-
toring of the information accessed, something not pos-
sible with paper based materials. Tailored approaches
can be more effective in generating change in
behaviour,40 but whether they more effectively facili-
tate informed choices is unknown. Furthermore, since
web access is socially patterned, its use was not appro-
priate for the current trial. In 2009, 21% of UK adults
had never used the internet,41 a group disproportio-
nately represented among the participants of particular
interest in this trial—namely, those who are socially
deprived.
Unanswered questions and future research
The generalisability of these findings to other screen-
ing programmes is unknown. The harms that can arise
from screening for diabetes were described in the invi-
tation as comprising worry and false reassurance,
which participants may not consider serious. By con-
trast, participation in other screening programmes can
entail serious physical harms from subsequent invasive
testing such as colonoscopy, or treatment such as pros-
tatectomy. The impact of increasing knowledge about
the limited individual benefit and potential harms of
treatment after screening has been studiedmost exten-
sively in the context of screening for prostate cancer.
The evidence is mixed: in one review increasing
knowledge had no impact28 but in another it reduced
uptake.42 Studies are needed to compare the impact of
presenting uncertainty about individual benefit and
harm across screening programmes with different
types and levels of harm and benefit. Our findings
also contribute to a broader debate about the most
effective and acceptable ways to communicate about
screening programmes.43 Furthermore, the study
hypotheses focused on attendance, and little informa-
tion was collected on non-attenders. Future studies
need to focus on non-attenders to understand better
their reasons for non-attendance as a basis for enabling
informed choices in this group.
Conclusions
We observed no conflict between efforts to achieve
informed choices and attendance for a population
health screening programme for diabetes. Attendance
was low, however, and socially deprived groups, who
are most vulnerable to disease, were least likely to
attend. Further attention to only the content of an invi-
tation is unlikely to achieve equity in uptake of preven-
tive services. Those designing and implementing
screening as well as other prevention programmes
need to consider how to overcome these inequities
most effectively.
We thank study participants and the staff at Bretton Medical Practice,
Peterborough; Old Fletton Surgery, Peterborough; The Rookery Medical
Centre, Newmarket; and Thorney Medical Practice, Peterborough; the
nurses who conducted the screening clinics led by Marian Bosman; the
Medical Research Council field epidemiology team; Nicola Popplewell,
Helen Morris, Kate Williams, and Rachel Crockett for their contribution to
the development of the study and the materials; and Irwin Nazareth,
Graham Watt, and Dan Mason for their contribution to discussion of the
results. ALK, TMM, SG, and SS are founder members of the National
Institute for Health Research School for Primary Care Research. ALK and
SS are National Institute of Health Research senior investigators. SG
receives support from the Department of Health National Institute for
Health Research programme grant funding scheme (RP-PG-0606-1259).
The General Practice and Primary Care Research Unit is supported by
WHAT IS ALREADY KNOWN ON THIS TOPIC
Health policies now hold that participation in screening
programmes should reflect “informed choice”
Informed choice requires the communication of the chances
of individual benefit and harm of screening, and actions
consistent with participants’ values
Such choice may deter attendance, particularly among
socially disadvantaged groups, and so increase inequalities
in health
WHAT THIS STUDY ADDS
Providing information to support choice does not adversely
affect attendance for screening
More socially deprived groups are, however, less likely to
attend regardless of type of invitation
Those designing and implementing screening and other
prevention programmes need to consider how to most
effectively overcome inequities in use of screening
RESEARCH
page 6 of 7 BMJ | ONLINE FIRST | bmj.com
Page 7
funds from the National Institute for Health Research. IK is supported by a
Medical Research Council co-op grant (RG35746).
Contributors:TMM and ALK defined the research question. TMM, ALK, SS,
ATP, IK, and SG participated in the design of the trial and intervention. SS,
EM, and SG directed the intervention team; and EM directed the trial
coordination team. ATP wrote the statistical analysis plan and JV did the
statistical analyses. All authors participated in the acquisition and analysis
of data and critical revision of the manuscript, have seen and approved
the final version, had full access to all study data, and were jointly
responsible for the decision to submit for publication. TMM is guarantor
for the paper.
Funding: This trial was funded by the Wellcome Trust (grant No 076838
“Didactic versus informed choice invitations: balancing public health
benefits and individual choice” principal investigator TMM). The funding
body had no role in study design, data collection, analysis, interpretation,
or writing of the report.
Competing interests: All authors have completed the unified competing
interest form at www.icmje.org/coi_disclosure.pdf (available on request
from the corresponding author). SG has received honorariums from Eli
Lilly, GlaxoSmithKline, Merck, Sharp & Dohme, Colgate Palmolive,
Unilever, the University of Western Ontario, and the National Health
Service for undertaking lectures at educational meetings not directly
related to the topic of this paper. His second class rail travel costs for
attending Department of Health meetings concerning the NHS health
check were reimbursed by the Department of Health.
Ethical approval: This study was approved by the Cambridgeshire 1
research ethics committee (reference 06/Q0104/17).
Data sharing: Study materials and documents described in the General
Medical Council guidelines for consent are available from the
corresponding author at theresa.marteau@kcl.ac.uk.
1 Rose G. Sick individuals and sick populations. Int J Epidemiol
2001;30:427-32.
2 Wood DA, Kinmonth AL, Davies GA, Yarwood J, Thompson SD, Pyke
SDM, et al. Randomised controlled trial evaluating cardiovascular
screening and intervention in general practice: principal results of
British family heart study. BMJ 1994;308:313-20.
3 Jorgensen K, Gotzsche PC. Content of invitations for publicly funded
screening mammography. BMJ 2006;332:538-41.
4 Marteau TM, Dormandy E, Michie S. A measure of informed choice.
Health Expect 2001;4:99-108.
5 Marteau TM. Informed choice: a construct in search of a name. In:
Edwards A, Elwyn G, eds. Shared decision-making in health care.
Oxford University Press, 2009:87-94.
6 Cooke R, French D. How well do the theory of reasoned action and
theory of planned behaviour predict intentions and attendance at
screening programmes? A meta-analysis. Psychol Health
2008;23:745-65.
7 Marteau TM, Hankins M, Collins B. Perceptions of risk of cervical
cancer and attitudes towards cervical screening: a comparison of
smokers and non-smokers. Fam Pract 2002;19:18-22.
8 Tudor Hart J. The inverse care law. Lancet 1971;1:405-12.
9 Crockett R, Wienmann J, Hankins M, Marteau TM. Time orientation
and health-related behaviour: measurement in general population
samples. Psychol Health 2009;24:18.
10 Orbell S, HaggerM. Temporal framingand thedecision to takepart in
type 2 diabetes screening: effects of individual differences in
consideration of future consequences on persuasion.Health Psychol
2006;25:537-48.
11 Raffle AE. Information about screening—is it to achieve high uptake
or to ensure informed choice? Health Expect 2001;4:92-8.
12 Griffin SJ, Little PS, Hales CN, Kinmonth AL, Wareham NJ. Diabetes
risk score: towards earlier detection of type 2 diabetes in general
practice. Diabetes Metab Res Rev 2000;16:164-71.
13 Adriaanse CA, Snoek FJ. The psychological impact of screening for
type 2 diabetes. Diabetes Metab Res Rev 2006;22:20-5.
14 Holman RR, Paul SK, Bethel MA, Matthews DR, Neil HA. 10-year
follow-up of intensive glucose control in type 2 diabetes. N Engl J
Med 2008;359:1577-89.
15 Department of Health. Putting prevention first. Vascular checks: risk
assessment and management. Stationery Office, 2008.
16 Kohro T, Furui Y, Mitsutake N, Fujii R, Morita H, Oku S, et al. The
Japanese national health screening and intervention program aimed
at preventing worsening of the metabolic syndrome. Int Heart J
2008;49:193-203.
17 MannE, Prevost AT,Griffin S, Kellar I, SuttonS, ParkerM, et al. Impact
of an informed choice invitation on uptake of screening for diabetes
in primary care (DICISION): trial protocol. BMC Public Health
2009;9:63.
18 Waugh N, Scotland G, McNamee P, Gillett M, Brennan A, Goyder E,
et al. Screening for type 2 diabetes: literature review and economic
modelling. Health Technol Assess 2007;11:iii-iv,ix-xi,1-125.
19 Muir J, Mant D, Jones L, Yudkin P, on behalf of the Imperial Cancer
Research FundOXCHECK study group. Effectiveness of health checks
conducted by nurses in primary care: results of the OXCHECK study
after one year. BMJ 1994;308:308-12.
20 Goyder EC. Screening for and prevention of type 2 diabetes. BMJ
2008;336:1140-1.
21 Echouffo-Tcheugui JB, Simmons RK, Williams KM, Barling RS,
Prevost AT, Kinmonth AL, et al. The ADDITION-Cambridge trial
protocol: a cluster-randomised controlled trial of screening for type 2
diabetes and intensive treatment for screen-detected patients. BMC
Public Health 2009;9:136.
22 General Medical Council. Seeking patients’ consent: the ethical
considerations. GMC, 1998.
23 Gilhooley C, Green C. Protocol analysis: theoretical background. In:
Richardson JTE, ed. Handbook of qualitative research methods for
psychology and the social sciences. BPS Books, 1996:43-54.
24 Patel VL, Arocha JF, Diermeier M, How J, Mottur-Pilson C. Cognitive
psychological studies of representation and use of clinical practice
guidelines. Int J Med Inf 2001;63:147-67.
25 Skaner Y, Backlund L, Montgomery H, Bring J, Strender LE. General
practitioners’ reasoning when considering the diagnosis heart
failure: a think-aloud study. BMC Fam Pract 2005;6:4.
26 Flesch [Java program]. 2.0 version, 2007.
27 Kellar I, Sutton S, Griffin S, Prevost AT, Kinmonth AL, Marteau TM.
Evaluation of an informed choice invitation for type 2 diabetes
screening. Patient Educ Couns 2008;72:232-8.
28 Fox R. Informed choice in screening programmes: do leaflets help? A
critical literature review. J Public Health 2006;28:309-17.
29 Kim LG, Thompson SG, Marteau TM, Scott RA. Screening for
abdominal aortic aneurysms: the effects of age and social
deprivation on screening uptake, prevalence and attendance at
follow-up in the MASS trial. J Med Screen 2004;11:50-3.
30 McCaffery K, Wardle J, Nadel M, Atkin W. Socioeconomic variation in
participation in colorectal cancer screening. J Med Screen
2002;9:104-8.
31 Dormandy E, Michie S, Hooper R, Marteau T. Informed choice in
antenatal Down syndrome screening: a cluster-randomised trial of
combined versus separate visit testing. Patient Educ Couns
2006;61:56-64.
32 Trevena LJ, Irwig L, Barratt A. Randomized trial of a self-administered
decision aid for colorectal cancer screening. J Med Screen
2008;15:76-82.
33 Mathieu E, Barratt A, Davey HM, McGeechan K, Howard K,
Houssami N. Informed choice in mammography screening: a
randomized trial of a decision aid for 70-year-oldwomen.Arch Intern
Med 2007;167:2039-46.
34 Shaw C, Abrams K, Marteau T. Psychological impact of predicting
individuals’ risks of illness: a systematic review. Soc Sci Med
1999;49:1571-98.
35 Goyder E, Wild S, Fischbacher C, Carlisle J, Peters J. Evaluating the
impact of a national pilot screeningprogramme for type2diabetes in
deprived areas of England. Fam Pract 2008;25:370-5.
36 Marsh GN, Channing DM. Narrowing the health gap between a
deprived and an endowed community. BMJ 1988;296:173-6.
37 Atri J, Falshaw M, Gregg R, Robson J, Omar RZ, Dixon S. Improving
uptake of breast screening inmultiethnic populations: a randomised
controlled trial using practice reception staff to contact non-
attenders. BMJ 1997;315:1356-9.
38 Gallo C, Perrone F, De Placido S, Giusti C. Informed versus
randomised consent to clinical trials. Lancet 1995;346:1060-4.
39 Kreuter MW, Bull FC, Clark EM, Oswald DL. Understanding how
people process health information: a comparison of tailored and
nontailored weight-loss materials. Health Psychol 1999;18:487-94.
40 Noar SM, Benac CN, Harris MS. Does tailoring matter? Meta-analytic
reviewof tailoredprint healthbehavior change interventions.Psychol
Bull 2007;133:673-93.
41 Office for National Statistics. Internet access: Households and
individuals. Stat Bull 28 Aug;2009.
42 O’Connor AM, Stacey D, Entwistle V, Llewellyn-Thomas H, Rovner D,
Holmes-Rovner M, et al. Decision aids for people facing health
treatment or screening decisions. Cochrane Database Syst Rev
2003;(2):CD001431.
43 Entwistle VA, Carter SM, Trevena L, Flitcroft K, Irwig L, McCaffery K,
et al. Communicating about screening. BMJ 2008;337:a1591.
Accepted: 27 January 2010
RESEARCH
BMJ | ONLINE FIRST | bmj.com page 7 of 7
Medical Research Council co-op grant (RG35746).
Contributors:TMM and ALK defined the research question. TMM, ALK, SS,
ATP, IK, and SG participated in the design of the trial and intervention. SS,
EM, and SG directed the intervention team; and EM directed the trial
coordination team. ATP wrote the statistical analysis plan and JV did the
statistical analyses. All authors participated in the acquisition and analysis
of data and critical revision of the manuscript, have seen and approved
the final version, had full access to all study data, and were jointly
responsible for the decision to submit for publication. TMM is guarantor
for the paper.
Funding: This trial was funded by the Wellcome Trust (grant No 076838
“Didactic versus informed choice invitations: balancing public health
benefits and individual choice” principal investigator TMM). The funding
body had no role in study design, data collection, analysis, interpretation,
or writing of the report.
Competing interests: All authors have completed the unified competing
interest form at www.icmje.org/coi_disclosure.pdf (available on request
from the corresponding author). SG has received honorariums from Eli
Lilly, GlaxoSmithKline, Merck, Sharp & Dohme, Colgate Palmolive,
Unilever, the University of Western Ontario, and the National Health
Service for undertaking lectures at educational meetings not directly
related to the topic of this paper. His second class rail travel costs for
attending Department of Health meetings concerning the NHS health
check were reimbursed by the Department of Health.
Ethical approval: This study was approved by the Cambridgeshire 1
research ethics committee (reference 06/Q0104/17).
Data sharing: Study materials and documents described in the General
Medical Council guidelines for consent are available from the
corresponding author at theresa.marteau@kcl.ac.uk.
1 Rose G. Sick individuals and sick populations. Int J Epidemiol
2001;30:427-32.
2 Wood DA, Kinmonth AL, Davies GA, Yarwood J, Thompson SD, Pyke
SDM, et al. Randomised controlled trial evaluating cardiovascular
screening and intervention in general practice: principal results of
British family heart study. BMJ 1994;308:313-20.
3 Jorgensen K, Gotzsche PC. Content of invitations for publicly funded
screening mammography. BMJ 2006;332:538-41.
4 Marteau TM, Dormandy E, Michie S. A measure of informed choice.
Health Expect 2001;4:99-108.
5 Marteau TM. Informed choice: a construct in search of a name. In:
Edwards A, Elwyn G, eds. Shared decision-making in health care.
Oxford University Press, 2009:87-94.
6 Cooke R, French D. How well do the theory of reasoned action and
theory of planned behaviour predict intentions and attendance at
screening programmes? A meta-analysis. Psychol Health
2008;23:745-65.
7 Marteau TM, Hankins M, Collins B. Perceptions of risk of cervical
cancer and attitudes towards cervical screening: a comparison of
smokers and non-smokers. Fam Pract 2002;19:18-22.
8 Tudor Hart J. The inverse care law. Lancet 1971;1:405-12.
9 Crockett R, Wienmann J, Hankins M, Marteau TM. Time orientation
and health-related behaviour: measurement in general population
samples. Psychol Health 2009;24:18.
10 Orbell S, HaggerM. Temporal framingand thedecision to takepart in
type 2 diabetes screening: effects of individual differences in
consideration of future consequences on persuasion.Health Psychol
2006;25:537-48.
11 Raffle AE. Information about screening—is it to achieve high uptake
or to ensure informed choice? Health Expect 2001;4:92-8.
12 Griffin SJ, Little PS, Hales CN, Kinmonth AL, Wareham NJ. Diabetes
risk score: towards earlier detection of type 2 diabetes in general
practice. Diabetes Metab Res Rev 2000;16:164-71.
13 Adriaanse CA, Snoek FJ. The psychological impact of screening for
type 2 diabetes. Diabetes Metab Res Rev 2006;22:20-5.
14 Holman RR, Paul SK, Bethel MA, Matthews DR, Neil HA. 10-year
follow-up of intensive glucose control in type 2 diabetes. N Engl J
Med 2008;359:1577-89.
15 Department of Health. Putting prevention first. Vascular checks: risk
assessment and management. Stationery Office, 2008.
16 Kohro T, Furui Y, Mitsutake N, Fujii R, Morita H, Oku S, et al. The
Japanese national health screening and intervention program aimed
at preventing worsening of the metabolic syndrome. Int Heart J
2008;49:193-203.
17 MannE, Prevost AT,Griffin S, Kellar I, SuttonS, ParkerM, et al. Impact
of an informed choice invitation on uptake of screening for diabetes
in primary care (DICISION): trial protocol. BMC Public Health
2009;9:63.
18 Waugh N, Scotland G, McNamee P, Gillett M, Brennan A, Goyder E,
et al. Screening for type 2 diabetes: literature review and economic
modelling. Health Technol Assess 2007;11:iii-iv,ix-xi,1-125.
19 Muir J, Mant D, Jones L, Yudkin P, on behalf of the Imperial Cancer
Research FundOXCHECK study group. Effectiveness of health checks
conducted by nurses in primary care: results of the OXCHECK study
after one year. BMJ 1994;308:308-12.
20 Goyder EC. Screening for and prevention of type 2 diabetes. BMJ
2008;336:1140-1.
21 Echouffo-Tcheugui JB, Simmons RK, Williams KM, Barling RS,
Prevost AT, Kinmonth AL, et al. The ADDITION-Cambridge trial
protocol: a cluster-randomised controlled trial of screening for type 2
diabetes and intensive treatment for screen-detected patients. BMC
Public Health 2009;9:136.
22 General Medical Council. Seeking patients’ consent: the ethical
considerations. GMC, 1998.
23 Gilhooley C, Green C. Protocol analysis: theoretical background. In:
Richardson JTE, ed. Handbook of qualitative research methods for
psychology and the social sciences. BPS Books, 1996:43-54.
24 Patel VL, Arocha JF, Diermeier M, How J, Mottur-Pilson C. Cognitive
psychological studies of representation and use of clinical practice
guidelines. Int J Med Inf 2001;63:147-67.
25 Skaner Y, Backlund L, Montgomery H, Bring J, Strender LE. General
practitioners’ reasoning when considering the diagnosis heart
failure: a think-aloud study. BMC Fam Pract 2005;6:4.
26 Flesch [Java program]. 2.0 version, 2007.
27 Kellar I, Sutton S, Griffin S, Prevost AT, Kinmonth AL, Marteau TM.
Evaluation of an informed choice invitation for type 2 diabetes
screening. Patient Educ Couns 2008;72:232-8.
28 Fox R. Informed choice in screening programmes: do leaflets help? A
critical literature review. J Public Health 2006;28:309-17.
29 Kim LG, Thompson SG, Marteau TM, Scott RA. Screening for
abdominal aortic aneurysms: the effects of age and social
deprivation on screening uptake, prevalence and attendance at
follow-up in the MASS trial. J Med Screen 2004;11:50-3.
30 McCaffery K, Wardle J, Nadel M, Atkin W. Socioeconomic variation in
participation in colorectal cancer screening. J Med Screen
2002;9:104-8.
31 Dormandy E, Michie S, Hooper R, Marteau T. Informed choice in
antenatal Down syndrome screening: a cluster-randomised trial of
combined versus separate visit testing. Patient Educ Couns
2006;61:56-64.
32 Trevena LJ, Irwig L, Barratt A. Randomized trial of a self-administered
decision aid for colorectal cancer screening. J Med Screen
2008;15:76-82.
33 Mathieu E, Barratt A, Davey HM, McGeechan K, Howard K,
Houssami N. Informed choice in mammography screening: a
randomized trial of a decision aid for 70-year-oldwomen.Arch Intern
Med 2007;167:2039-46.
34 Shaw C, Abrams K, Marteau T. Psychological impact of predicting
individuals’ risks of illness: a systematic review. Soc Sci Med
1999;49:1571-98.
35 Goyder E, Wild S, Fischbacher C, Carlisle J, Peters J. Evaluating the
impact of a national pilot screeningprogramme for type2diabetes in
deprived areas of England. Fam Pract 2008;25:370-5.
36 Marsh GN, Channing DM. Narrowing the health gap between a
deprived and an endowed community. BMJ 1988;296:173-6.
37 Atri J, Falshaw M, Gregg R, Robson J, Omar RZ, Dixon S. Improving
uptake of breast screening inmultiethnic populations: a randomised
controlled trial using practice reception staff to contact non-
attenders. BMJ 1997;315:1356-9.
38 Gallo C, Perrone F, De Placido S, Giusti C. Informed versus
randomised consent to clinical trials. Lancet 1995;346:1060-4.
39 Kreuter MW, Bull FC, Clark EM, Oswald DL. Understanding how
people process health information: a comparison of tailored and
nontailored weight-loss materials. Health Psychol 1999;18:487-94.
40 Noar SM, Benac CN, Harris MS. Does tailoring matter? Meta-analytic
reviewof tailoredprint healthbehavior change interventions.Psychol
Bull 2007;133:673-93.
41 Office for National Statistics. Internet access: Households and
individuals. Stat Bull 28 Aug;2009.
42 O’Connor AM, Stacey D, Entwistle V, Llewellyn-Thomas H, Rovner D,
Holmes-Rovner M, et al. Decision aids for people facing health
treatment or screening decisions. Cochrane Database Syst Rev
2003;(2):CD001431.
43 Entwistle VA, Carter SM, Trevena L, Flitcroft K, Irwig L, McCaffery K,
et al. Communicating about screening. BMJ 2008;337:a1591.
Accepted: 27 January 2010
RESEARCH
BMJ | ONLINE FIRST | bmj.com page 7 of 7
Sign up today - FREE
Mendeley saves you time finding and organizing research. Learn more
- All your research in one place
- Add and import papers easily
- Access it anywhere, anytime
Start using Mendeley in seconds!
Readership Statistics
5 Readers on Mendeley
by Discipline
60% Medicine
40% Psychology
by Academic Status
60% Post Doc
20% Ph.D. Student
20% Researcher (at an Academic Institution)
by Country
40% United Kingdom
20% Canada
20% United States
Groups
 |