Emory University, Office of Health Promotion and Disease Prevention, Atlanta, GA 30303, USA.
Curr Med Res Opin. 2013 Jul;29(7):773-81. doi: 10.1185/03007995.2013.802229. Epub 2013 May 23.
Statin dose, adherence, and cardiovascular (CV) outcomes are important factors when considering switching statin therapies. The objective of the study was to compare CV event rates and risk in managed care patients receiving atorvastatin versus those switched to simvastatin from atorvastatin.
Patients 18-64 years, with ≥3 continuous pharmacy claims for atorvastatin between 1/1/05-11/30/07 and ≥12 months pre- and ≥3 months post-index continuous eligibility were identified using HealthCore Integrated Research Database (HIRD). Patients were stratified into two cohorts: one continued atorvastatin without interruption and the other switched to simvastatin. Patients were matched 1:10 (continue atorvastatin/switch simvastatin) on five variables, excluding lipid parameters due to limited data availability. Descriptive statistics were reported for sample characteristics. A multivariate Cox proportional hazards model was developed to evaluate adjusted CV risk.
In total 73,960 atorvastatin patients and 7396 simvastatin-switch patients were analyzed. The mean age was 54 ± 7 years (both cohorts). Mean follow-up was 440 days for atorvastatin patients and 237 days for simvastatin-switch patients. Mean dose and therapy duration for atorvastatin was 20 mg and 321 days compared with 33 mg and 195 days for simvastatin-switch, respectively. Of the simvastatin-switch patients, 32% were switched to a less potent simvastatin dose (<2× prior atorvastatin dose). After adjusting for demographic/clinical characteristics, no significant differences were found in CV risk between cohorts.
Limitations include use of administrative claims data without lipid level laboratory results data and the length of follow-up which may not have been sufficient to demonstrate significant differences in event rates between groups.
In this managed care population, no significant differences were found in risk of CV events among patients switching to simvastatin compared to patients continuing atorvastatin. Switched patients may differ from controls for reasons not captured in the database.
在考虑转换他汀类药物治疗时，他汀类药物剂量、依从性和心血管（CV）结局是重要因素。本研究的目的是比较接受阿托伐他汀治疗的患者和从阿托伐他汀转换为辛伐他汀的患者的 CV 事件发生率和风险。
使用 HealthCore Integrated Research Database（HIRD），确定 2005 年 1 月 1 日至 2007 年 11 月 30 日期间有≥3 次连续阿托伐他汀用药记录，且在索引前≥12 个月和索引后≥3 个月连续符合资格的 18-64 岁患者。将患者分为两组：一组继续使用阿托伐他汀且无中断，另一组转换为辛伐他汀。由于数据有限，排除血脂参数，根据五个变量对患者进行 1:10 配对（继续使用阿托伐他汀/转换为辛伐他汀）。报告样本特征的描述性统计数据。采用多变量 Cox 比例风险模型评估调整后的 CV 风险。
共分析了 73960 例阿托伐他汀患者和 7396 例辛伐他汀转换患者。平均年龄为 54±7 岁（两组）。阿托伐他汀患者的平均随访时间为 440 天，辛伐他汀转换患者为 237 天。阿托伐他汀的平均剂量和治疗时间分别为 20mg 和 321 天，而辛伐他汀转换患者分别为 33mg 和 195 天。辛伐他汀转换患者中，32%的患者转换为低剂量辛伐他汀（<2 倍于之前的阿托伐他汀剂量）。调整人口统计学/临床特征后，两组间 CV 风险无显著差异。
本研究存在一定局限性，包括使用行政索赔数据，而没有血脂水平实验室结果数据，以及随访时间可能不足以证明两组之间的事件发生率存在显著差异。
在本管理式医疗人群中，与继续使用阿托伐他汀的患者相比，转换为辛伐他汀的患者的 CV 事件风险无显著差异。转换患者可能因数据库中未捕获的原因与对照组存在差异。
