The win ratio approach did not alter study conclusions and may mitigate concerns regarding unequal composite end points in kidney transplant trials

Abstract

Objectives: The aim of the study was to determine the impact of using the win ratio approach and investigate whether this approach alters the interpretations or conclusions of a randomized trial in kidney transplantation.

Study design and setting: We present an application of the win ratio approach in a kidney transplant trial that assessed the clinical effectiveness of ramipril treatment vs. placebo. The primary composite outcome included the time to death, kidney transplant failure, or doubling of serum creatinine. We compare the win ratio to a conventional hazard ratio (HR) from the original trial. A win ratio with a lower 95% confidence limit greater than 1 indicates a positive treatment effect with statistical significance.

Results: For the primary composite end point, ramipril treatment resulted in a win ratio of 1.21 (95% confidence interval [CI], 0.55-2.59) vs. a HR of 0.76 (95% CI, 0.38-1.51). With extended follow-up (mean 48 months), ramipril was associated with a win ratio of 1.02 (95% CI, 0.54-1.83) vs. a HR of 0.96 (95% CI, 0.55-1.65).

Conclusion: The win ratio approach produced results similar to the original time-to-event analysis. Using this approach would not alter the conclusion of the original trial and lessens concerns associated with composite components of unequal clinical importance.

Keywords: ACE inhibitor; Composite end points; Kidney transplant; Novel analysis methods; Randomized controlled trial; Unequal trial composite; Win ratio.