Slejko Julia F, Ho Michael, Anderson Heather D, Nair Kavita V, Sullivan Patrick W, Campbell Jonathan D
University of Washington School of Pharmacy, Seattle, WA, 98195-7630, USA.
J Manag Care Pharm. 2014 Jan;20(1):51-7. doi: 10.18553/jmcp.2014.20.1.51.
Adherence to statins in real-world practice settings is known to be suboptimal. However, less is known about how adherence changes over time and whether changes in adherence are associated with adverse cardiovascular (CV) outcomes.
To (a) characterize yearly changes in adherence among initially adherent patients taking statins for primary prevention and (b) assess the association between changes in statin adherence with subsequent risk of CV events.
A 10% random sample of the IMS LifeLink Health Plan Claims Database covering the time period from July 1, 1997, to December 31, 2008, was used to identify a cohort of primary prevention statin users. Adherence was estimated in yearly segments beginning with the index statin prescription using proportion of days covered (PDC). PDC was categorized into 3 levels: PDC ≥ 0.80, 0.20 ≤ PDC < 0.80, PDC < 0.20. Patients were excluded if they experienced CV events or had PDC < 0.80 in their first year of statin exposure. Descriptive statistics were used to explore proportions of the cohort in each PDC category during each year. Cox-proportional hazards models were used to estimate the 5-year CV event risk associated with yearly adherence transitions.
Of the 11,126 patients beginning at the highest level of adherence (PDC ≥ 0.80) in year 1, 70% remained at this level in year 2. Of those in this level during year 2, 73% remained at this level in year 3. 828 (7.44%) experienced a CV event during their observable follow-up time. It was found that those who transitioned from the highest to the lowest level of adherence in year 2 (PDC < 0.20) experienced 2.26 greater CV event hazard (P < 0.0001). Adjusting for year 2 adherence, patients at the lowest level in year 3 experienced a 271% increase in CV hazard (P < 0.0001), as compared with the highest level of adherence.
This study found that patients' adherence levels tend to decline over time, and a transition to levels of adherence lower than a PDC of 80% was associated with increased risk of CV events. These results are useful in the context of targeting interventions that aim to improve patients' adherence.
在现实世界的实践环境中，他汀类药物的依从性普遍欠佳。然而，关于依从性如何随时间变化以及依从性变化是否与不良心血管（CV）结局相关，我们所知甚少。
（a）描述最初依从的他汀类药物一级预防使用者的依从性年度变化情况；（b）评估他汀类药物依从性变化与后续CV事件风险之间的关联。
使用IMS LifeLink健康计划索赔数据库10%的随机样本，该数据库涵盖1997年7月1日至2008年12月31日的时间段，以确定一组一级预防他汀类药物使用者。从他汀类药物索引处方开始，按年度段使用覆盖天数比例（PDC）估算依从性。PDC分为3个水平：PDC≥0.80、0.20≤PDC＜0.80、PDC＜0.20。如果患者发生CV事件或在他汀类药物暴露的第一年PDC＜0.80，则将其排除。使用描述性统计来探索每年各PDC类别中该队列的比例。使用Cox比例风险模型来估计与年度依从性转变相关的5年CV事件风险。
在第1年开始时依从性最高水平（PDC≥0.80）的11126例患者中，70%在第2年仍保持该水平。在第2年处于该水平的患者中，73%在第3年仍保持该水平。828例（7.44%）患者在可观察的随访期内发生了CV事件。研究发现，在第2年从最高依从水平转变为最低依从水平（PDC＜0.20）的患者发生CV事件的风险增加2.26倍（P＜0.0001）。在调整第2年的依从性后，第3年处于最低依从水平的患者与最高依从水平相比，CV风险增加271%（P＜0.0001）。
本研究发现患者的依从性水平往往会随着时间下降，转变为低于PDC 80%的依从水平与CV事件风险增加相关。这些结果对于旨在改善患者依从性的靶向干预措施具有指导意义。
