Clinical Pharmacology and Pharmacy, Department of Public Health, University of Southern Denmark, DK-5000, Odense, Denmark.
Quality Use of Medicines and Pharmacy Research Centre, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia.
Pharmacoepidemiol Drug Saf. 2018 Aug;27(8):867-871. doi: 10.1002/pds.4582. Epub 2018 Jun 27.
Standard Kaplan-Meier (KM) survival analysis is often used to study treatment persistence estimating the proportion of patients who have not yet experienced a treatment break by a given day after treatment initiation. This method only allows patients to be studied until their first treatment break. The "proportion of patients covered" (PPC) method is another approach to study treatment persistence. It measures the proportion of live patients currently covered by treatment. We aimed to describe the PPC method, show how the KM survival analysis and the PPC method can describe treatment persistence, and discuss the interpretation/application of the methods.
We identified new users of statins, selective serotonin reuptake inhibitors, hormone replacement therapy, and ibuprofen. We used KM estimates and the PPC to describe persistence in the 3 years post treatment initiation, using a grace period of 90 days to define a treatment break.
Three years after statin initiation, approximately 40% of patients were still in continuous treatment (KM survival) and 60% of patients still alive were in current treatment (PPC). Corresponding numbers were 12% and 25% for selective serotonin reuptake inhibitors and 9% and 29% for hormone replacement therapy. At 1 year, numbers were 5% and 10% for ibuprofen. The PPC showed markedly less variability than the KM survival analysis with different choices of grace periods.
The KM survival analysis and the PPC method can be used to study different aspects of treatment persistence. Together, they provide a more complete picture of treatment persistence and drug use patterns.
标准 Kaplan-Meier（KM）生存分析常用于研究治疗持续性，通过计算起始治疗后特定时间点尚未经历治疗中断的患者比例来估计患者的治疗持续情况。该方法仅允许患者在首次治疗中断前进行研究。“患者覆盖率比例（PPC）”方法是另一种研究治疗持续性的方法。它衡量了当前接受治疗的存活患者的比例。我们旨在描述 PPC 方法，展示 KM 生存分析和 PPC 方法如何描述治疗持续性，并讨论这些方法的解释/应用。
我们确定了新使用他汀类药物、选择性 5-羟色胺再摄取抑制剂、激素替代疗法和布洛芬的患者。我们使用 KM 估计值和 PPC 来描述起始治疗后 3 年内的持续性，使用 90 天的宽限期来定义治疗中断。
他汀类药物起始治疗 3 年后，约 40%的患者仍在持续治疗（KM 生存），60%仍存活的患者仍在接受当前治疗（PPC）。选择性 5-羟色胺再摄取抑制剂和激素替代疗法分别对应为 12%和 25%，9%和 29%。在 1 年内，布洛芬的数值分别为 5%和 10%。与不同宽限期选择相比，PPC 显示出明显小于 KM 生存分析的变异性。
KM 生存分析和 PPC 方法可用于研究治疗持续性的不同方面。两者结合可更全面地描述治疗持续性和药物使用模式。
