Estimating the Overall Risk Difference in the Analysis of Comparative Studies with Binary Outcomes

Thomas M. Menino Convention & Exhibition Center 

Multiple comparative studies with binary outcomes are frequently used in biomedical research to estimate the overall risk difference (ORD) for evaluating drug efficacy and profile safety. However, estimating the ORD is challenging, particularly when trial sizes are small or when studies report zero events. While the ORD is traditionally estimated using a weighted average of summary statistics from 2x2 tables, this approach is often biased because it excludes zero-event studies or relies on continuity corrections. In contrast, model-based methods can more effectively incorporate zero-event studies. In this article, we develop several efficient model-based estimation procedures for the ORD and compare them against weighted average-based methods through simulation studies. Finally, we demonstrate these procedures by analyzing a real-world dataset related to COVID-19 and associated diseases.

Binary outcomes

Comparative studies

Estimation procedures

Overall risk difference, 

Biometrics Section