Statistical Analysis
REGRESSION, EVENT
Assuming that the cumulative incidence would be 10% in the deferred vaccination group during the month 3 follow-up and the proportion dropping out in both groups would be 15%, we estimated that an overall sample of 1314 participants would provide 80% power to detect a hazard ratio (HR) for early vaccination recommendation of 1.50 for the primary outcome compared with deferred vaccination recommendation, at a 2-sided significance level of The primary analysis was performed according to the intention-to-treat principle in all randomized participants, regardless of their adherence to the assigned recommendation. Outcome times were calculated from randomization to the encounter reporting the end point event or the last follow-up. Time-to-event data were analyzed using the Kaplan-Meier method, with trial groups compared using a log-rank test and HRs calculated using Cox proportional hazards regression. The proportional hazards assumption was met as confirmed by inspection of log-log survival plot (eFigure in Binary outcomes are presented as numbers with proportions. We calculated 95% CIs for between-group differences in proportions using the Wilson score method.