Background: Patient adherence to treatment regimens may be a critical mediator between physician recommendations and patient outcomes, but levels of adherence have not been compared across disease groups, and patient self-reports have not been well validated.
Methods: To determine recall of and adherence to physicians' recommendations among patients with chronic medical conditions and to measure the correspondence between self-reported adherence and disease activity, we analyzed data from the Medical Outcomes Study. A total of 1751 patients with diabetes mellitus, hypertension, and heart disease were identified among 20,223 patients visiting family physicians, general internists, cardiologists, and endocrinologists in 1986. Main outcome measures included recall of 15 disease-specific recommendations, self-reported general and specific adherence, and correlations between adherence and clinical measures of disease activity and control.
Results: Among patients in all three disease groups, the proportion recalling recommendations to take prescribed medications (> or = 90%) exceeded the fraction recalling recommendations to follow a restricted diet, exercise regularly, and perform various self-care activities (22% to 84%). Adherence to recalled recommendations was similar across conditions but varied markedly according to the nature of the recommendations; for example, 91% of diabetics took prescribed medications but 69% followed a diabetics diet and 19% engaged in regular exercise. Adherence to recommendations was correlated with reduced serum glucose (r = -.33) and glycohemoglobin (r = -.25) levels among insulin-dependent diabetics and with reduced diastolic blood pressure among patients with hypertension (r = -.15).
Conclusions: The majority of chronically ill patients failed to recall elements of potentially important medical advice and did not always adhere to advice that was recalled. Self-reported adherence was correlated with clinical measures of disease activity and control. Additional research is needed not only to improve adherence to medical advice in patients with chronic illnesses but also to determine which life-style changes are truly beneficial for these patients.