Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK; Centre for Health Economics and Policy Innovation, Imperial College Business School, Imperial College London, London, UK.
Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK.
Lancet Glob Health. 2019 Sep;7(9):e1189-e1196. doi: 10.1016/S2214-109X(19)30266-9. Epub 2019 Jul 27.
Voluntary licences are increasingly being used to expand access to patented essential medicines in low-income and middle-income countries (LMICs). Since 2014, non-exclusive voluntary licences have been issued by Gilead and Bristol-Myers Squibb for key drugs for hepatitis C virus (HCV) infection. We aimed to evaluate the effect of these licences on access to HCV treatment.
We conducted a difference-in-differences analysis, exploiting the staggered and selective introduction of voluntary licensing in different countries, to identify the effect of voluntary licensing agreements on treatment uptake. We extracted Polaris Observatory data on the total number of people infected with HCV, diagnosed with HCV, and treated for HCV, and constructed a longitudinal panel of LMICs over a 13-year period (2004-16). Countries were included if they were classified as LMICs by the World Bank in 2014, and had available data on HCV outcomes. The exposure was defined as inclusion in any voluntary licence agreement for HCV drugs. Treatment uptake was calculated as the number of people treated for HCV in a given year per 1000 living people ever diagnosed with HCV. We fit difference-in-differences linear regression models controlling for different confounders that could influence treatment access and uptake, including country and year fixed effects and a range of country-level factors. We additionally assessed the dynamics of the effect and the robustness of our findings.
35 countries were included in the panel: 19 in the intervention group and 16 in the control group. In the simplest model, adjusting only for country and year fixed effects, voluntary licences were associated with an increase in the annual number of people accessing HCV treatment of 69·3 per 1000 diagnosed (95% CI 46·7-91·9; p=0·0060). After adjusting for country-level covariates, this increase was 53·6 per 1000 diagnosed (25·8-81·5; p=0·0354). The effect of licensing increased over time, and was largest in the second year after implementation. Results were robust to alternative specifications.
Voluntary licensing initiatives appear to substantially improve HCV treatment uptake in eligible countries. This evidence supports the expansion of licensing strategies to include more countries and more treatments.
Unitaid and Médecins Sans Frontières.
自愿许可正越来越多地被用于扩大在低收入和中等收入国家（LMICs）获得专利基本药物的机会。自 2014 年以来，吉利德和百时美施贵宝为丙型肝炎病毒（HCV）感染的关键药物颁发了非独占自愿许可。我们旨在评估这些许可对 HCV 治疗获得的影响。
我们进行了差异中的差异分析，利用自愿许可在不同国家的交错和选择性引入，以确定自愿许可协议对治疗效果的影响。我们从 Polaris 观察站提取了关于 HCV 感染人数、诊断 HCV 人数和 HCV 治疗人数的总人数，并在 13 年期间（2004-16 年）构建了一个 LMICs 的纵向面板。如果这些国家在 2014 年被世界银行归类为 LMICs，并且有 HCV 结果的数据，那么这些国家就包括在内。暴露被定义为纳入任何 HCV 药物的自愿许可协议。治疗效果的计算方法是在特定年份接受 HCV 治疗的人数除以曾诊断出 HCV 的活人数。我们使用差异中的差异线性回归模型控制了可能影响治疗效果和接受度的不同混杂因素，包括国家和年份固定效应以及一系列国家层面的因素。我们还评估了效果的动态和我们发现的稳健性。
该面板包括 35 个国家：19 个在干预组，16 个在对照组。在最简单的模型中，仅调整国家和年份固定效应，自愿许可与每年接受 HCV 治疗的人数增加 69.3 人/1000 人有关（95%CI46.7-91.9；p=0.0060）。在调整了国家层面的协变量后，这一数字增加了 53.6 人/1000 人（25.8-81.5；p=0.0354）。许可的效果随着时间的推移而增加，在实施后的第二年最大。结果在替代规格下是稳健的。
自愿许可举措似乎大大提高了符合条件的国家的 HCV 治疗效果。这一证据支持扩大许可策略，以包括更多的国家和更多的治疗方法。
联合国艾滋病规划署和无国界医生组织。
