DECIPHer, School of Social Sciences, Cardiff University, Cardiff, UK.
EPPI-Centre, UCL Institute of Education, London, UK.
Res Synth Methods. 2019 Sep;10(3):389-397. doi: 10.1002/jrsm.1341. Epub 2019 Feb 20.
Qualitative comparative analysis (QCA) was originally developed as a tool for cross-national comparisons in macrosociology, but its use in evaluation and evidence synthesis of complex interventions is rapidly developing. QCA is theory-driven and relies on Boolean logic to identify pathways to an outcome (eg, is the intervention effective or not?). We use the example of two linked systematic reviews on weight management programs (WMPs) for adults-one focusing on user views (a "views synthesis") and one focusing on the effectiveness of WMPs incorporating dietary and physical activity-to demonstrate how a synthesis of user views can supply a working theory to structure a QCA. We discuss how a views synthesis is especially apt to supply this working theory because user views can (a) represent a "middle-range theory" of the intervention; (b) bring a participatory, democratic perspective; and (c) provide an idiographic understanding of how the intervention works that external taxonomies may not be able to furnish. We then discuss the practical role that the views synthesis played in our QCA examining pathways to effectiveness: (a) by suggesting specific intervention features and sharpening the focus on the most salient features to be examined, (b) by supporting interpretation of findings, and (c) by bounding data analysis to prevent data dredging.
定性比较分析（QCA）最初是作为一种用于宏观社会学跨国比较的工具而开发的，但它在复杂干预措施的评估和证据综合中的应用正在迅速发展。QCA是理论驱动的，依赖于布尔逻辑来确定通向结果的途径（例如，干预是否有效？）。我们以两个关于成人体重管理计划（WMP）的系统评价为例，一个侧重于用户观点（“观点综合”），另一个侧重于纳入饮食和身体活动的 WMP 的有效性，来说明如何将用户观点综合起来为结构 QCA 提供一个工作理论。我们讨论了为什么观点综合特别适合提供这种工作理论，因为用户观点可以：（a）代表干预的“中观理论”；（b）带来参与式、民主的视角；（c）提供干预如何运作的个体理解，而外部分类法可能无法提供。然后，我们讨论了观点综合在我们的 QCA 中对有效性途径的实际作用：（a）通过建议特定的干预特征，并关注最显著的特征进行分析；（b）通过支持对发现的解释；（c）通过限制数据分析来防止数据挖掘。
