School of Public Health, University of Alberta, Edmonton, Alberta, Canada.
Faculty of Pharmacy, Université Laval, Quebec City, Quebec, Canada.
PLoS One. 2019 Sep 25;14(9):e0223062. doi: 10.1371/journal.pone.0223062. eCollection 2019.
Thresholds defining medication adherence are rarely evidence-based. A threshold of 0.8 is typically presumed to achieve improved outcomes. We aimed to assess the optimal threshold of adherence to lipid-lowering drugs (LLD) in predicting cardiovascular-related (CV) outcomes in patients with hypertension.
Cohort study of new users of LLDs.
Comprehensive healthcare administrative databases of the province of Alberta (Canada) from 2008 to 2016.
Patients with hypertension, who were new users of LLDs. Patients who had the outcomes prior to the initiation of LLD were excluded.
Hospitalization for acute coronary syndrome (ACS)/stroke, CV-related mortality and all-cause mortality.
Adherence to LLDs was assessed as the proportion of days covered (PDC) by any LLD, from drug initiation to censoring, outcome, or study end. Three methods were used to assess the threshold: Contal and O'Quigley method, minimum distance method, and Youden's J index. Cox regressions were used to assess the risk associated with each method-specific threshold and Akaike information criteria were used to retain the optimal threshold after adjustment.
52229 patients were included; 4.0% were hospitalized for ACS/stroke, 3.4% died, and 1.3% died from CV-related cause. In predicting ACS/stroke, CV-related and all-cause mortality, the optimal adherence threshold was 0.52 (range: 0.51-0.54), 0.79 (0.45-0.87), and 0.84 (0.79-0.89), respectively. These results were consistent among patients aged ≥ 65 years (n = 19804). However, the results varied among those aged < 65 years, where the incidence rates of outcomes were low.
In new-users of LLDs with hypertension, approximately 50% days covered by LLDs may be enough to prevent long-term occurrence of ACS, or stroke. However, a threshold near 0.80 may be needed to prevent or reduce the risk of all-cause or CV-related mortality.
用于定义药物依从性的阈值很少基于证据。通常假定依从性阈值为 0.8 可以改善结果。我们旨在评估降脂药物（LLD）依从性的最佳阈值，以预测高血压患者的心血管相关结局。
新使用 LLD 的患者的队列研究。
2008 年至 2016 年加拿大艾伯塔省全面的医疗保健管理数据库。
新使用 LLD 的高血压患者。在开始使用 LLD 之前发生结局的患者被排除在外。
急性冠状动脉综合征（ACS）/中风住院、心血管相关死亡率和全因死亡率。
从药物开始到 censoring、结局或研究结束，用任何 LLD 覆盖的天数（PDC）评估 LLD 的依从性。使用三种方法评估阈值：Contal 和 O'Quigley 方法、最小距离法和 Youden 的 J 指数。Cox 回归用于评估每种方法特定阈值的风险，Akaike 信息准则用于在调整后保留最佳阈值。
共纳入 52229 例患者；4.0%因 ACS/中风住院，3.4%死亡，1.3%死于心血管相关原因。在预测 ACS/中风、心血管相关和全因死亡率方面，最佳依从性阈值分别为 0.52（范围：0.51-0.54）、0.79（0.45-0.87）和 0.84（0.79-0.89）。在≥65 岁的患者（n=19804）中，结果一致。然而，在<65 岁的患者中，结果有所不同，结局的发生率较低。
在新使用 LLD 的高血压患者中，大约 50%的 LLD 覆盖天数可能足以预防 ACS 或中风的长期发生。然而，可能需要接近 0.80 的阈值来预防或降低全因或心血管相关死亡率的风险。
