Abstract
We undertook a prospective study to assess the long-term compliance of Japanese male workers with drug treatment for hypercholesterolemia. In workers who accepted treatment with simvastatin, an HMG-CoA reductase inhibitor, compliance was monitored every 6 months with an interview. Factors affecting compliance were identified by using the background characteristics of subjects and a self-administered questionnaire on their type of job, job style, private lifestyle and psychological status at work. Mean (SD) follow-up periods were 21.5 (10.6) months for 640 workers, and 240 noncompliant (<75% of prescription) subjects were found. Of these 240, 23 (9.6%) were restored to be finally compliant at the last follow-up (re-compliant). We assessed the time-course rate of compliant subjects and factors affecting drug compliance using Cox proportional hazard model by setting occurrence of a noncompliant attitude to an endpoint. The cumulative compliance rate at 36 months was 0.508 when excluding 23 re-compliant subjects and 0.529 when considering them as compliant. Multivariate analysis showed that age and present medical illness with hypertension (HT) in background characteristics of subjects and the habit of having breakfast daily in factors related to private-lifestyle were significantly associated with compliance. Baseline lipid profiles and work related issues were not associated with compliance. The occurrence rate of side effects did was similar in compliant and noncompliant workers. In this study, even though considering the re-compliant subjects, the rate of compliant subjects over a 3-yr period was considerably low (around 50%). The factors related to compliance were age, present illness with HT and the habit of having breakfast daily.
