The impact of the single exit price policy on a basket of generic medicines in South Africa, using a time series analysis from 1999 to 2014

Background
Regulating pharmaceutical markets have become a key strategy by most governments in ensuring the availability and accessibility of quality medicines to its citizens. The South African government, when faced with high medicine prices, implemented the Single Exit Price (SEP) in 2004. This study assessed the impact of the of the Single Exit Price (SEP) regulation introduced in South Africa in 2004 on a basket of generic.
Method
Private sector price data of a basket of medicines (December 1999 to December 2014) was obtained from various price files (Pharmacy Software Vendors and Community Pharmacy). The price of the medicine was expressed in a single unit dose. The medicines investigated used the WHO/HAI methodology. The Interrupted Time-Series (ITS) model was used to estimate the change in slope and level of medicines investigated (50 originator and its available generics) before and after the policy change.
Results
Majority of the medicines analysed reflect a substantial decrease in medicine prices immediately after implementation of the pricing regulations as reflected in both the change in level and the change in slope using the interrupted time series analysis.
Discussion
This study indicates that the SEP regulation had an impact on medicine pricing in South Africa in both the short (immediately on the introduction) and long term (over the study period). Most medicines investigated showed a smaller yearly increase in price compared to before regulations.
Conclusion
This study provides evidence of the impact of medicine pricing intervention from a middle–income country, and useful lessons can be drawn by other developing countries looking at introducing medicine price controls.

研究背景
监管医药市场已成为多数国家保障本国公民可获得且可及优质药品的核心策略。南非政府在面临高企的药品价格问题时，于2004年推出了单一出口价格（Single Exit Price, SEP）政策。本研究旨在评估南非2004年实施的单一出口价格（SEP）监管政策对一批仿制药的影响。

研究方法
本研究从两类价格数据源（药房软件供应商及社区药房的价格文件）获取了1999年12月至2014年12月期间的私营部门药品价格数据。所有药品价格均以单剂剂量作为计价单位。本研究采用世界卫生组织/健康行动国际（WHO/HAI）标准方法开展药品调研，并运用中断时间序列（Interrupted Time-Series, ITS）模型，估算政策变更前后所调研药品（50种原研药及其可获得的仿制药）的价格斜率与水平变化。

研究结果
经中断时间序列分析显示，多数被分析药品在价格监管政策实施后即刻出现了显著的价格下降，这一变化同时体现在价格水平与价格增速（斜率）的改变上。

讨论
本研究表明，单一出口价格监管政策对南非药品定价的影响兼具短期（政策实施即刻）与长期（研究全周期）效应。相较于政策实施前，多数被调研药品的年度价格涨幅显著收窄。

结论
本研究为中等收入国家的药品定价干预政策效果提供了实证依据，同时可为其他拟实施药品价格管控的发展中国家提供有益借鉴。