Using natural experimental studies to guide public health action: turning the evidence-based medicine paradigm on its head
Using natural experimental studies to guide public health action: turning the evidence-based medicine paradigm on its head
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DOI：
10.1136/jech-2019-213085
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发表时间：
2020-02-01
影响因子：
6.3
通讯作者：
White, Martin
中科院分区：
文献类型：
--
作者：
Ogilvie, David;Adams, Jean;White, Martin
尽管效果较小，但在人口一级提供的预防非传染性疾病的干预措施通常比向高危群体提供的干预措施具有更大的范围、影响和公平性。然而，如何以这种方式改变人口行为模式仍然是研究和政策的最大不确定因素之一。更容易评价的行为改变干预措施的证据往往掩盖了产生和维持更健康行为的全人口和全系统办法的证据。人口健康干预措施通常作为自然实验实施，这使得其评估比典型的随机对照试验（RCT）更加复杂和不可预测。我们讨论了评估自然实验及其对公共卫生政策证据的独特贡献日益重要。我们对比既定的循证实践途径，其中随机对照试验为特定的干预措施产生“明确”的证据，与基于实践的证据途径，其中评估可以帮助调整现有政策的指南针轴承。我们建议，干预研究应侧重于减少关键的不确定性，非随机研究设计应被接受，而不是容忍，需要一个更细致入微的方法来评估不同类型的证据的效用。指导公共卫生行动所需的复杂证据不一定与提供无偏效应量估计所需的证据相同。基于实践的证据途径既不差，也不只是最好的，当所有其他方法都失败了。这往往是产生有意义的证据来解决有关投资于人口健康干预措施的关键问题的唯一途径。
Despite smaller effect sizes, interventions delivered at population level to prevent non-communicable diseases generally have greater reach, impact and equity than those delivered to high-risk groups. Nevertheless, how to shift population behaviour patterns in this way remains one of the greatest uncertainties for research and policy. Evidence about behaviour change interventions that are easier to evaluate tends to overshadow that for population-wide and system-wide approaches that generate and sustain healthier behaviours. Population health interventions are often implemented as natural experiments, which makes their evaluation more complex and unpredictable than a typical randomised controlled trial (RCT). We discuss the growing importance of evaluating natural experiments and their distinctive contribution to the evidence for public health policy. We contrast the established evidence-based practice pathway, in which RCTs generate 'definitive' evidence for particular interventions, with a practice-based evidence pathway in which evaluation can help adjust the compass bearing of existing policy. We propose that intervention studies should focus on reducing critical uncertainties, that non-randomised study designs should be embraced rather than tolerated and that a more nuanced approach to appraising the utility of diverse types of evidence is required. The complex evidence needed to guide public health action is not necessarily the same as that which is needed to provide an unbiased effect size estimate. The practice-based evidence pathway is neither inferior nor merely the best available when all else fails. It is often the only way to generate meaningful evidence to address critical questions about investing in population health interventions.