The effectiveness of community interventions to increase fruit and vegetable consumption in people four years of age and older

Abstract

To examine the effectiveness of community interventions to increase fruit and vegetable consumption in people aged 4 years and older. Studies that examined an intervention intended to alter fruit and vegetable consumption were eligible for inclusion in the review. Four studies were targeted at parents of young children, six at school-aged children, and five at adults, with two of the latter about worksite interventions. A professional nutritionist conducted most of the interventions. Studies that included participants over 4 years of age were eligible for inclusion. The participants included in the review were: low-income mothers (n=4,106), grade 4 to 9 school children and Girl Scout troops (number not reported), adult patients at family practice offices (n=394), women at risk of breast cancer (n=303), adult workers (n=29,762) and unspecified (1 study). Studies that provided information on the process or outcome evaluation were eligible for inclusion in the review. The specific outcome measures assessed were the consumption of fruit and vegetables, attitude change towards eating nutritious foods and vegetables, and knowledge about healthy eating. Prospective studies with a comparison group were eligible for inclusion. Randomised controlled trials (RCT), controlled trials (CCTs) and cohort analytic studies were included. Studies that were rated as 'weak' for the validity assessment were excluded. CINAHL, the Cochrane Library, Current Contents, Dissertation Abstracts, EMBASE, ERIC, HealthSTAR, MEDLINE, the Public Health Effectiveness Project Database, PsycINFO and Sociological Abstracts were searched without language restrictions from the first year of each of the databases to August 1998. The search terms were provided in the paper. In addition, journals were handsearched back to either 1993 or 1988 : American Journal of Public Health, American Journal of Epidemiology, American Journal of Health Promotion, Canadian Journal of Public Health, Health Education and Behaviour, Health Promotion International, Journal of Epidemiology and Community Health (back to 1993); Journal of Nutrition Education, Journal of School Health, Canadian Journal of Dietetic Practice and Research, Journal of the American Dietetic Association, Nutrition Reviews, Australian Journal of Dietetics, European Journal of Nutrition, and Health Education Quarterly (back to 1988). The validity of the articles was assessed according to the following criteria: selection bias, study design, confounders, blinding, data collection methods, and the handling of withdrawals and drop-outs. Each criterion was rated as strong, moderate or weak, then a global rating (strong, moderate or weak) of the paper was also achieved. A study was rated as 'strong' if four of the six individual ratings were strong with no weak ratings; 'moderate' if it achieved less than four strong ratings and only one weak; and 'weak' if two or more criteria received weak ratings. Two reviewers independently assessed the validity of the primary studies. The reviewers did not state how any disagreements were resolved. Two reviewers independently assessed the retrieved articles for inclusion in the review. The reviewers did not state how any disagreements were resolved. Two reviewers independently extracted the data. The reviewers did not state how any disagreements were resolved. Data on study author, year and geographical location, design and quality, participants, intervention, outcomes and results were extracted and tabulated. A narrative synthesis was undertaken with the studies being grouped by intervention. Differences between the studies were discussed by recourse to the type of intervention, the length of the programme and whether or not it was a multi- or uni-component intervention. Fifteen studies (total n from 12 studies = 36,926) were included: 1 RCT (n=150), 12 CCTs (n=36,671, n not reported for 2 studies) and 2 cohort analytic studies (n=171, n not reported for 1 study). There was support for the use of peer educators and paraprofessionals with low-income mothers, although a study of a direct comparison of two groups led by a professional nutritionist versus a paraprofessional has not been found. The most effective interventions gave clear messages about increasing fruit and vegetable consumption; incorporated multiple strategies that reinforced the messages; involved the family; were more intensive; were provided over a longer period of time, rather than one or two contacts; and were based on a theoretical framework. The authors addressed a clear review question in terms of the type of intervention, participants and outcome measures that were to be included in the review. The literature search was thorough, but was restricted to published studies; this means that relevant unpublished studies may have been missed. The review process, in terms of the inclusion of studies, the validity assessment and data extraction, was explicit and was undertaken systematically by more than one reviewer, although it was not stated how any discrepancies between the reviewers were handled. Appropriate steps were taken in all of these processes to minimise bias. Adequate details of the primary study characteristics were provided in the paper, allowing the reader to assess whether the authors' results and conclusion are consistent with the evidence base reviewed. The narrative summary of the results was appropriate. Overall, this was a reasonably well-conducted review in which a number of steps were taken to minimise bias in the review process. The authors' results and conclusions are consistent with the primary studies reviewed. Practice: The authors stated that managers who make decisions about nutrition interventions need to consider the resource requirement of the more intensive intervention programmes. The use of paraprofessionals was effective in the EFNEP studies. Consideration should, therefore, be given to the use of paraprofessionals or peer educators who are trained and supervised by nutritionists to deliver education and skill-based programmes to low-income populations. Managers will also need to ensure that the intervention has been developed from a theoretical base, has a specific message about increasing fruit and vegetable consumption, and has a component about behaviour change.