Department of Public Health, Environments and Society, London School of Hygiene and Tropical Medicine, London, UK.
Centre for Statistical Methodology, London School of Hygiene & Tropical Medicine, London, UK.
Int J Epidemiol. 2018 Dec 1;47(6):2082-2093. doi: 10.1093/ije/dyy135.
Interrupted time series analysis differs from most other intervention study designs in that it involves a before-after comparison within a single population, rather than a comparison with a control group. This has the advantage that selection bias and confounding due to between-group differences are limited. However, the basic interrupted time series design cannot exclude confounding due to co-interventions or other events occurring around the time of the intervention. One approach to minimizse potential confounding from such simultaneous events is to add a control series so that there is both a before-after comparison and an intervention-control group comparison. A range of different types of controls can be used with interrupted time series designs, each of which has associated strengths and limitations. Researchers undertaking controlled interrupted time series studies should carefully consider a priori what confounding events may exist and whether different controls can exclude these or if they could introduce new sources of bias to the study. A prudent approach to the design, analysis and interpretation of controlled interrupted time series studies is required to ensure that valid information on the effectiveness of health interventions can be ascertained.
中断时间序列分析与大多数其他干预研究设计不同，它涉及在单个人群内进行前后比较，而不是与对照组进行比较。这具有优势，即由于组间差异导致的选择偏差和混杂因素受到限制。然而，基本的中断时间序列设计不能排除由于同时发生的干预措施或其他事件引起的混杂。一种最小化潜在混杂的方法是添加一个对照系列，以便既有前后比较，又有干预对照比较。中断时间序列设计可以使用多种不同类型的对照，每种对照都有其相关的优势和局限性。进行对照中断时间序列研究的研究人员应仔细考虑事先可能存在哪些混杂事件，以及不同的对照是否可以排除这些事件，或者它们是否会给研究带来新的偏倚来源。需要谨慎地设计、分析和解释对照中断时间序列研究，以确保可以确定健康干预措施的有效性的有效信息。
