Contracts between patients and healthcare practitioners for improving patients' adherence to treatment, prevention and health promotion activities

BACKGROUND: Contracts are a verbal or written agreement that a patient makes with themselves, with healthcare practitioners, or with carers, where participants commit to a set of behaviours related to the care of a patient. Contracts aim to improve the patients' adherence to treatment or health promotion programmes. OBJECTIVES: To assess the effects of contracts between patients and healthcare practitioners on patients' adherence to treatment, prevention and health promotion activities, the stated health or behaviour aims in the contract, patient satisfaction or other relevant outcomes, including health practitioner behaviour and views, health status, reported harms, costs, or denial of treatment as a result of the contract. SEARCH STRATEGY: We searched: the Cochrane Consumers and Communication Review Group's Specialised Register (in May 2004); the Cochrane Central Register of Controlled Trials (CENTRAL), (The Cochrane Library 2004, issue 1); MEDLINE 1966 to May 2004); EMBASE (1980 to May 2004); PsycINFO (1966 to May 2004); CINAHL (1982 to May 2004); Dissertation Abstracts. A: Humanities and Social Sciences (1966 to May 2004); Sociological Abstracts (1963 to May 2004); UK National Research Register (2000 to May 2004); and C2-SPECTR, Campbell Collaboration (1950 to May 2004). SELECTION CRITERIA: We included randomised controlled trials comparing the effects of contracts between healthcare practitioners and patients or their carers on patient adherence, applied to diagnostic procedures, therapeutic regimens or any health promotion or illness prevention initiative for patients. Contracts had to specify at least one activity to be observed and a commitment of adherence to it. We included trials comparing contracts with routine care or any other intervention. DATA COLLECTION AND ANALYSIS: Selection and quality assessment of trials were conducted independently by two review authors; single data extraction was checked by a statistician. We present the data as a narrative summary, given the wide range of interventions, participants, settings and outcomes, grouped by the health problem being addressed. MAIN RESULTS: We included thirty trials, all conducted in high income countries, involving 4691 participants. Median sample size per group was 21. We examined the quality of each trial against eight standard criteria, and all trials were inadequate in relation to three or more of these standards. Trials evaluated contracts in addiction (10 trials), hypertension (4 trials), weight control (3 trials) and a variety of other areas (13 trials). Sixteen trials reported at least one outcome that showed statistically significant differences favouring the contracts group, five trials reported at least one outcome that showed differences favouring the control group and 26 trials reported at least one outcome without differences between groups. Effects on adherence were not detected when measured over longer periods. AUTHORS' CONCLUSIONS: There is limited evidence that contracts can potentially contribute to improving adherence, but there is insufficient evidence from large, good quality studies to routinely recommend contracts for improving adherence to treatment or preventive health regimens