What influences persistence with medicines? A multinational discrete choice experiment of 2549 patients.

AIM: The aim was to examine patients' stated preferences to persist with medicines and to explore the influence of psychosocial and sociocognitive factors. METHODS: Community-dwelling, hypertensive patients recruited from nine European countries were invited to complete a discrete choice experiment (DCE) with attributes for treatment benefits, mild yet common adverse drug reactions (ADRs), rare but potentially life-threatening ADRs and dosing frequency. Patients responded to the binary choice of which medicine would they be most likely to continue taking. Data were analyzed using a random effects logit model. RESULTS: Two thousand five hundred and forty-nine patients from Austria (n = 321), Belgium (n = 175), England (n = 315), Germany (n = 266), Greece (n = 288), Hungary (n = 322), the Netherlands (n = 231), Poland (n = 312) and Wales (n = 319) completed the DCE. All attributes significantly influenced patients' stated preference to persist with medications (P < 0.05). Patients were willing to accept decreases in treatment benefits of 50.6 percentage points (95% CI 46.1, 57.9) for a very rare (as opposed to rare) risk of severe ADR, 28.3 percentage points (95% CI 25.2, 33.1) for a once daily instead of twice daily dosing and 0.74 percentage points (95% CI 0.67, 0.85) for a 1% point reduction in mild ADRs. Models accounting for psychosocial and sociocognitive characteristics were significantly different from the base case. CONCLUSION: Patients' intention to persist with treatment was associated with their willingness to trade potential benefits, harms and dosing frequency. Psychosocial and sociocognitive factors influenced the extent of trading. The utility model may have value in assessing patients' likelihood of persisting with medicines and to tailor treatment to maximize persistence.

Predictors of self-reported adherence to antihypertensive medicines: a multinational, cross-sectional survey.

BACKGROUND: Nonadherence to antihypertensive medicines limits their effectiveness, increases the risk of adverse health outcome, and is associated with significant health care costs. The multiple causes of nonadherence differ both within and between patients and are influenced by patients' care settings. OBJECTIVES: The objective of this article was to identify determinants of patient nonadherence to antihypertensive medicines, drawing from psychosocial and economic models of behavior. METHODS: Outpatients with hypertension from Austria, Belgium, England, Germany, Greece, Hungary, The Netherlands, Poland, and Wales were recruited to a cross-sectional online survey. Nonadherence to medicines was assessed using the Morisky Medication Adherence Scale (primary outcome) and the Medication Adherence Rating Scale. Associations with adherence and nonadherence were tested for demographic, clinical, and psychosocial factors. RESULTS: A total of 2595 patients completed the questionnaire. The percentage of patients classed as nonadherent ranged from 24% in The Netherlands to 70% in Hungary. Low age, low self-efficacy, and respondents' perceptions of their illness and cost-related barriers were associated with nonadherence measured on the Morisky Medication Adherence Scale across several countries. In multilevel, multivariate analysis, low self-efficacy (odds ratio = 0.73; 95% confidence interval 0.70-0.77) and a high number of perceived barriers to taking medicines (odds ratio = 1.70; 95% confidence interval 1.38-2.09) were the main significant determinants of nonadherence. Country differences explained 11% of the variance in nonadherence. CONCLUSIONS: Among the variables measured, patients' adherence to antihypertensive medicines is influenced primarily by their self-efficacy, illness beliefs, and perceived barriers. These should be targets for interventions for improving adherence, as should an appreciation of differences among the countries in which they are being delivered.

Predicting adherence to medications using health psychology theories: a systematic review of 20 years of empirical research.

OBJECTIVES: This review sought to identify the empirical evidence for the application of models from sociocognitive theory, self-regulation theory, and social support theory at predicting patient adherence to medications. METHODS: A systematic review of the published literature (1990-2010) using MEDLINE, EMBASE, Cochrane Library, CINAHL, and PsychINFO identified studies examining the application of health psychology theory to adherence to medication in adult patients. Two independent reviewers extracted data on medication, indication, study population, adherence measure, theory, model, survey instruments, and results. Heterogeneity in theoretical model specification and empirical investigation precluded a meta-analysis of data. RESULTS: Of 1756 unique records, 67 articles were included (sociocognitive = 35, self-regulation = 21, social support = 11). Adherence was most commonly measured by self-report (50 of 67). Synthesis of studies highlighted the significance (P ≤ 0.05) of self-efficacy (17 of 19), perceived barriers (11 of 17), perceived susceptibility (3 of 6), necessity beliefs (8 of 9), and medication concerns (7 of 8). CONCLUSIONS: The results of this review provide a foundation for the development of theory-led adherence-enhancing interventions that could promote sustainable behavior change in clinical practice.