Evaluating the Desirability of Outcome Ranking (DOOR) and Response Adjusted for Duration of Antibiotic Risk (RADAR) for Clinical Trials of Antibiotics in Pediatric Pneumonia.

Objective outcomes for pediatric community-acquired pneumonia (CAP) are lacking. The desirability of outcome ranking (DOOR) and response adjusted for duration of antibiotic risk (RADAR) outcome encompass clinical benefit and adverse effects, while also accounting for antibiotic exposure. We evaluated DOOR/RADAR through simulations and compared sample size considerations to non-inferiority designs in a hypothetical trial comparing antibiotics to no antibiotics (i.e., placebo) for children with mild CAP. We also evaluated a trial comparing different durations of antibiotics. Three scenarios were considered - one with no difference in DOOR between the two groups, one in which placebo is more efficacious, and another in which amoxicillin is more efficacious than placebo. Power to detect a difference between arms was greater using DOOR/RADAR compared to DOOR. Assuming a sample size of 200, DOOR had 2.5%, 50%, and 65% power to detect a statistical difference between arms for Scenarios 1-3, respectively, significantly less than DOOR/RADAR. Importantly, DOOR/RADAR incorrectly identified placebo as superior in Scenario 3 where amoxicillin was truly efficacious. Sample size requirements for non-inferiority designs were larger to achieve similar levels of power as DOOR and DOOR/RADAR. DOOR/RADAR has the potential to lead to an incorrect conclusion declaring placebo superior when amoxicillin is efficacious.