Confidence limits for the averted infections ratio estimated via the counterfactual placebo incidence rate.

ABSTRACT:

Objectives

The averted infections ratio (AIR) is a novel measure for quantifying the preservation-of-effect in active-control non-inferiority clinical trials with a time-to-event outcome. In the main formulation, the AIR requires an estimate of the counterfactual placebo incidence rate. We describe two approaches for calculating confidence limits for the AIR given a point estimate of this parameter, a closed-form solution based on a Taylor series expansion (delta method) and an iterative method based on the profile-likelihood.

Methods

For each approach, exact coverage probabilities for the lower and upper confidence limits were computed over a grid of values of (1) the true value of the AIR (2) the expected number of counterfactual events (3) the effectiveness of the active-

SUBMITTER: Dunn DT 

PROVIDER: S-EPMC9204757 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature