Wellcome Centre for Cultures & Environments of Health, University of Exeter, Exeter, UK.
Institute for Culture and Society, Western Sydney University, Sydney, Australia.
BMC Med Res Methodol. 2022 Dec 1;22(1):307. doi: 10.1186/s12874-022-01790-8.
Case study methodology is widely used in health research, but has had a marginal role in evaluative studies, given it is often assumed that case studies offer little for making causal inferences. We undertook a narrative review of examples of case study research from public health and health services evaluations, with a focus on interventions addressing health inequalities. We identified five types of contribution these case studies made to evidence for causal relationships. These contributions relate to: (1) evidence about system actors' own theories of causality; (2) demonstrative examples of causal relationships; (3) evidence about causal mechanisms; (4) evidence about the conditions under which causal mechanisms operate; and (5) inference about causality in complex systems. Case studies can and do contribute to understanding causal relationships. More transparency in the reporting of case studies would enhance their discoverability, and aid the development of a robust and pluralistic evidence base for public health and health services interventions. To strengthen the contribution that case studies make to that evidence base, researchers could: draw on wider methods from the political and social sciences, in particular on methods for robust analysis; carefully consider what population their case is a case 'of'; and explicate the rationale used for making causal inferences.
案例研究方法在健康研究中被广泛应用，但在评估性研究中作用不大，因为人们通常认为案例研究对做出因果推断贡献不大。我们对来自公共卫生和卫生服务评估的案例研究进行了叙述性综述，重点关注解决健康不平等问题的干预措施。我们确定了这些案例研究对因果关系证据的五种贡献。这些贡献涉及：（1）关于系统参与者自身因果理论的证据；（2）因果关系的示范性示例；（3）因果机制的证据；（4）因果机制运作条件的证据；以及（5）复杂系统中因果关系的推断。案例研究可以并且确实有助于理解因果关系。在报告案例研究时提高透明度，将提高其可发现性，并有助于为公共卫生和卫生服务干预措施建立一个稳健而多元化的证据基础。为了加强案例研究对该证据基础的贡献，研究人员可以：借鉴政治学和社会科学中的更广泛方法，特别是稳健分析方法；仔细考虑他们的案例是针对哪个群体的；并说明做出因果推断所使用的基本原理。
