Competing Risk Regression Models for Epidemiologic Data

TLDR

Competing events can preclude the event of interest in epidemiologic data, requiring extensions of survival analysis that epidemiologists should select based on their scientific question. The paper outlines three regression approaches for estimating cause‑specific and subdistribution relative hazards in competing risks analysis. The authors compare risk‑set structures and parameter interpretations of these methods and illustrate them using WIHS data on time to antiretroviral therapy initiation versus disease progression. In the WIHS example, women with injection drug use history were less likely to start therapy before AIDS or death (csRH = 0.67, sdRH = 0.60), while the risk of disease progression before treatment was higher (csRH = 1.71, sdRH = 2.01).

Abstract

Competing events can preclude the event of interest from occurring in epidemiologic data and can be analyzed by using extensions of survival analysis methods. In this paper, the authors outline 3 regression approaches for estimating 2 key quantities in competing risks analysis: the cause-specific relative hazard (csRH) and the subdistribution relative hazard (sdRH). They compare and contrast the structure of the risk sets and the interpretation of parameters obtained with these methods. They also demonstrate the use of these methods with data from the Women's Interagency HIV Study established in 1993, treating time to initiation of highly active antiretroviral therapy or to clinical disease progression as competing events. In our example, women with an injection drug use history were less likely than those without a history of injection drug use to initiate therapy prior to progression to acquired immunodeficiency syndrome or death by both measures of association (csRH = 0.67, 95% confidence interval: 0.57, 0.80 and sdRH = 0.60, 95% confidence interval: 0.50, 0.71). Moreover, the relative hazards for disease progression prior to treatment were elevated (csRH = 1.71, 95% confidence interval: 1.37, 2.13 and sdRH = 2.01, 95% confidence interval: 1.62, 2.51). Methods for competing risks should be used by epidemiologists, with the choice of method guided by the scientific question.