Department of Economics and Finance, University of Rome Tor Vergata, CHP PCOR Stanford University, Via Columbia, 2, 00133, Rome, Italy,
Int J Public Health. 2014 Apr;59(2):329-39. doi: 10.1007/s00038-013-0528-4. Epub 2013 Dec 15.
In this article we investigate the causal effect of cost-sharing schemes on compliance with statins in a quantile regression framework.
We use the health search CSD-LPD data, a longitudinal observational dataset containing computer-based patient records collected by Italian general practitioners. We exploit a series of natural experiments referring to several introductions of co-payment schemes in some of the Italian regions between 2000 and 2009. We adopt an extended difference-in-differences approach to provide quantile estimates of the impact of co-payments on compliance.
We find that (i) introduction of co-payments hurts residents of regions with worse quality and provision of health care; (ii) within these regions, co-payments were particularly harmful for high compliers; (iii) gender, clinical history and geographic residence are important determinants of compliance among poor compliers; (iv) compliance decreases with the potency and dosage of statins, particularly for poor compliers.
In the presence of inefficient health-care provision, co-payments are harmful for drug compliance, and this is especially true for patients who are originally good compliers.
本文旨在通过分位数回归框架研究成本分担方案对他汀类药物依从性的因果效应。
我们使用健康搜索 CSD-LPD 数据，这是一个包含意大利全科医生收集的基于计算机的患者记录的纵向观察数据集。我们利用了一系列自然实验，这些实验涉及 2000 年至 2009 年间意大利部分地区引入的几次共付方案。我们采用扩展的差异中差异方法来提供共付对依从性影响的分位数估计。
我们发现，（i）共付制度的引入对医疗质量和服务较差地区的居民不利；（ii）在这些地区，共付制度对高依从者尤其有害；（iii）性别、临床病史和地理居住是低依从者依从性的重要决定因素；（iv）依从性随他汀类药物的效力和剂量降低，尤其是对低依从者。
在医疗服务效率低下的情况下，共付制度对药物依从性不利，而对于原本依从性较好的患者尤其如此。
