Abstract
BackgroundWhile the benefit of adherence to statins on clinical outcomes has been proved, this benefit may be heterogeneous among patients who initiated statins for primary or secondary prevention purpose. This study aimed to investigate the impact of statin adherence on clinical outcomes among patients who initiated statins for primary and secondary prevention in China.MethodsAdult patients in Tianjin Urban Employee Basic Medical Insurance database who initiated ≥2 prescriptions of statins from 2012 through 2013 were included and grouped into primary and secondary prevention subgroups according to their cardiovascular diseases (CVD) history during the prior 12-month baseline period. Proportion of days covered (PDC) was used to measure statin adherence in the initial 12-month follow-up. Clinical outcomes were measured by the incidence of major adverse cardiovascular events (MACE) during the 13th–24th months follow-up, and were compared between the patients with PDC ≥ 0.5 and patients with PDC < 0.5 using Cox regression models in primary and secondary prevention subgroups. Sensitivity analyses were conducted in propensity score matched groups.Results99,655 patients were finally included. The mean (SD) PDC was 0.19 (0.15) in primary prevention subgroup (N = 34,372), with 5.4% patients had PDC ≥ 0.5. The patients with PDC ≥ 0.5 had a 37% reduced risk of MACE compared with patients with PDC < 0.5 (Unadjusted incidence rate of MACE: 1.1% vs. 1.4%; all-adjusted HR = 0.63; 95% CI, 0.41–0.98). While, no significant difference was observed in the secondary prevention subgroup (N = 65,283) between patients with PDC ≥ 0.5 and patients with PDC < 0.5 (Unadjusted incidence rate of MACE: 4.6% vs. 2.8%; all-adjusted HR = 1.08, 95% CI, 0.92–1.28). These findings were confirmed by the sensitivity analyses in propensity score matched groups.ConclusionsStatin adherence was very poor in China, and statin adherence is associated with decreased risk of MACE in patients for primary prevention, while further exploration is needed for secondary prevention.
Highlights
While the benefit of adherence to statins on clinical outcomes has been proved, this benefit may be heterogeneous among patients who initiated statins for primary or secondary prevention purpose
It was reported that only 35% ~ 70% patients were adherent to statins with a ≥ 80% proportion of days covered (PDC) or medication possession ratio (MPR) in developed countries including UK, Italy and Finland [8,9,10,11,12,13], and statin adherence could be even poorer in developing countries such as China
Different from the previous studies which focused all statin users as a whole, this study was conducted among statin users for primary and secondary prevention separately, which presented new evidence on the impact of statin adherence on the adverse clinical outcomes in new statin users
Summary
While the benefit of adherence to statins on clinical outcomes has been proved, this benefit may be heterogeneous among patients who initiated statins for primary or secondary prevention purpose. This study aimed to investigate the impact of statin adherence on clinical outcomes among patients who initiated statins for primary and secondary prevention in China. HMG-CoA reductase inhibitors (statins) are recommended as the first-line of lipid-lowering drug therapy in the primary and secondary prevention of cardiovascular events [1,2,3]. The impact of poor adherence on clinical outcomes may be different between statin users for primary prevention (those who don’t have prior cardiovascular disease, CVD) and secondary prevention (those who have prior CVD) of CVD. Related studies based on Asian population were very limited [8, 12, 21]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call