目的探讨反向配比设计在流行病学研究中的应用。方法以评价基因-环境交互作用的乳腺癌病因学研究为实例,介绍反向配比的设计方法和统计分析方法。结果该实例说明当人群中基因突变和感兴趣的环境暴露因素均为罕见因素时,使用反向配比设计可提高研究基因与环境交互作用的潜能。结论反向配比设计比传统的流行病学方法更适合研究包括罕见因素在内的交互作用。 Objective To explore the application of reverse ratio design in epidemiological studies. Methods The etiology of breast cancer with gene-environment interaction was evaluated as an example to introduce the design method and statistical analysis method of reverse proportioning. Results This example demonstrates that using reverse fit design can increase the potential for studying the interaction of a gene with the environment when both genetic mutations and environmental exposure factors of interest are rare in the population. Conclusion Reverse ratio design is more suitable than conventional epidemiological methods for studying interactions including rare factors.