Department of Global Health and Population, Harvard School of Public Health, Boston, Massachusetts, USA.
Sex Transm Infect. 2012 Mar;88(2):e2. doi: 10.1136/sextrans-2011-050303.
International donors financing the delivery of antiretroviral treatment in developing countries have recently emphasised their commitment to rigorous evaluation of antiretroviral treatment impact on population health. At the same time frame, but for different reasons, they have announced that they will shift funding from vertically structured (ie, disease-specific) interventions to horizontally structured interventions (ie, staff, systems and infrastructure that can deliver care for many diseases). The authors analyse likely effects of the latter shift on the feasibility of impact evaluation.
The authors examine the effect of the shift in intervention strategy on (1) outcome measurement, (2) cost measurement, (3) study-design options and the (4) technical and (5) political feasibility of programme evaluation.
As intervention structure changes from vertical to horizontal, outcome and cost measurements are likely to become more difficult (because the number of relevant outcomes and costs increases and the sources holding data on these measures become more diverse); study-design options become more limited (because it is often impossible to identify a rigorously defined counterfactual in horizontal interventions); the technical feasibility of interventions is reduced (because lag times between intervention and impact increase in length and effect-mediating and -modifying factors increase in number) and political feasibility of evaluation is decreased (because national policymakers may be reluctant to support the evaluation).
In the choice of intervention strategy, policymakers need to consider the effect of intervention strategy on impact evaluation. Methodological studies are needed to identify the best approaches to evaluate the population health impact of horizontal interventions.
为发展中国家提供抗逆转录病毒治疗资金的国际捐助者最近强调，他们致力于严格评估抗逆转录病毒治疗对人口健康的影响。与此同时，出于不同的原因，他们宣布将把资金从垂直结构（即针对特定疾病的干预措施）转向水平结构（即能够为多种疾病提供护理的人员、系统和基础设施）的干预措施。作者分析了后者转变对影响评估可行性的可能影响。
作者考察了干预策略转变对（1）结果测量、（2）成本测量、（3）研究设计方案以及（4）方案评估的技术和（5）政治可行性的影响。
随着干预结构从垂直向水平转变，结果和成本测量可能变得更加困难（因为相关结果和成本的数量增加，持有这些措施数据的来源变得更加多样化）；研究设计方案的选择变得更加有限（因为在水平干预措施中，通常不可能确定一个严格定义的反事实）；干预的技术可行性降低（因为干预和影响之间的滞后时间变长，影响中介和调节因素的数量增加），评估的政治可行性降低（因为国家政策制定者可能不愿意支持评估）。
在干预策略的选择中，政策制定者需要考虑干预策略对影响评估的影响。需要进行方法学研究，以确定评估水平干预对人口健康影响的最佳方法。
