Identification of Subgroups within a Japanese Older Adult Population for whom Statin Therapy is Effective in Reducing Mortality

The effects of statin use for primary prevention in reducing mortality among older adults in Asian populations are unknown. This study aimed to determine whether use of statins for primary prevention was associated with a decreased risk of all-cause mortality in a Japanese older adult population. A regional, population-based, longitudinal cohort study was conducted using the Shizuoka Kokuho Database (SKDB). Data were compared between the statin-treated group and a non-statin-treated (control) group using the inverse probability of treatment weighting (IPTW) method. In the SKDB cohort aged ≥65 years, new statin use was associated with a decreased risk of all-cause mortality (hazard ratio, 0.40; 95% confidence interval [CI], 0.33–0.48) after IPTW adjustment. The risk difference for mortality at 5 years in the statin-treated group (7.9%) compared with that in the control group (92.1%) was 0.05 (95% CI, 0.04–0.06), and the number needed to treat was 21.20 (95% CI, 18.10–24.70). In conclusion, statin use for primary prevention in older adults may reduce the risk of all-cause mortality in the population without atherosclerotic disease. Furthermore, statin use for primary prevention is feasible in patients aged 75 to <85 years and in patients with comorbidities such as diabetes, or dementia.