Pharmacist-led management of chronic pain in primary care: The PIPPC study

Abstract

Background: Chronic pain, (pain lasting >3 months) affects approximately half the population.[1] Recovery is rare. Most people are managed in primary care with drugs; sub-optimal prescribing, imperfect monitoring, and therapeutic duplication can lead to unsatisfactory management. Practice pharmacists are ideally placed to deal with these issues. A definitive RCT is planned to test the hypothesis that pharmacist medication-review, with or without prescribing, will lead to better patient functioning and/or better pain control than standard care. In line with the MRC framework for development and evaluation of complex interventions[2] an iterative approach including theoretical modelling, feasibility and pilot trials has been followed. This paper reports the main three month results of the pilot RCT. The main aims were to obtain estimates of patient recruitment and attrition rates; select outcome measures; estimate effect size and optimise the intervention. Ethical approval was obtained. Method(s): Six general practices with prescribing pharmacists in Grampian (3) and East Anglia (3) were recruited. A two-day pharmacist update in pain management was provided. Patients with chronic pain were identified by their prescribed analgesics/adjuvant drugs using a computerised search strategy[3]. GPs screened patients against inclusion criteria and mailed study invitations to a random sub-sample. Consenting patients were sent a baseline questionnaire (comprising SF-12, Chronic Pain Grade, Health Utility Index, ICECAP-O, HADS, demographic and cost items). Patients returning questionnaires were randomised to either one of two intervention groups (pharmacist medication-review with feedback to GP or pharmacist-medication review with ongoing pharmacist prescribing) or a control, treatment as usual, group. Patients were followed-up via postal questionnaire at three months post-randomisation. GPs and practice pharmacists were invited to interviews post-intervention to explore their experiences. Interviews were audiotaped, transcribed and content analysed. Result(s): Of 1397 patients contacted, 356 consented, 289 were sent a baseline questionnaire, 251 returned the questionnaire (87%) and 232 (145 females, mean age 65 years (SD = 12.3)) were randomised: review group (n = 84); prescribing group (n = 85); control group (n = 63). There was no difference between participants and non-participants in age, gender or deprivation. 99% received the intervention in the review group and 79% in prescribing group. 186 (86%) patients returned the three month follow-up questionnaire. At baseline 47 had had pain for <3 years, 92 for 3-10 years, and 93 for >10 years. CPG grading (a higher grade indicates high disability and pain intensity) could be calculated for (n = 211) and was for 24 (I), 60 (II), 48 (III), 79 (IV). Applying intention to treat analysis, at three months 19 patients in prescribing arm had a lower i.e. improved grading on the CPG, 14 in the review arm and 10 controls. Patients in the prescribing arm reported greater improvement in 6 of the 8 SF-12 subscales. Interviews showed that pharmacists were positive about the intervention. There was some ambivalence amongst GPs. Conclusion(s): The pilot trial has confirmed recruitment, response rates and change in outcomes support progressing to a definitive trial. There are indications that pharmacist prescribing confers benefit over medication-review alone or usual care.