Statin adherence and risk of all-cause, cancer, and cardiovascular mortality among dyslipidemia patients: A time-dependent analysis

Background and aim: Results have been mixed and uncertainty still remains regarding the impact of statin adherence on premature deaths. Thus, we investigated the association between statin adherence and risks of all-cause, cancer, and cardiovascular mortality among dyslipidemia patients in South Korea. Methods and results: We used data from the National Health Insurance Service (NHIS) National Sample Cohort for the years 2003–2013, which included data on 107,954 middle-aged and elderly dyslipidemia patients. Among these patients, a time-dependent Cox proportional hazards model was used to estimate the hazard ratios (HRs) of all-cause, cancer, and cardiovascular mortality depending on proportion of days covered (PDC) by statin medication. A total of 3073 (2.85%) individuals died within the study period. Of these individuals, 1143 (1.06%) died from cancer, and 687 (0.64%) died from cardiovascular diseases. Relative to good medication adherence (>80%), moderate (50–80%) (hazard ratio [HR]: 1.28, 95% confidence interval [CI]: 1.14–1.43) and poor (<50%) (HR: 1.58, 95% CI: 1.41–1.78) adherence were associated with increased risk of all-cause mortality. Poor adherence was also associated with increased risk of cancer (HR: 1.33, 95% CI: 1.16–1.52) and cardiovascular (HR: 1.27, 95% CI: 1.06–1.51) mortality. Conclusion: Such findings reveal that relative to good statin adherence, moderate and/poor adherence is associated with increased risks of all-cause, cancer, and cardiovascular mortality. Clinicians should assess for dyslipidemia, link statin adherence problems to potential mortality risk, and monitor outcomes in both medication adherence and disease complications.