Respiratory failure & ventilation
What is the optimal approach to analyse ventilator-free days? A simulation study
Authors' conclusion
The multistate model could be recommended as the optimal approach for analysing VFDs, as it outperformed the other methods and offers a more interpretable effect size than the proportional odds model and the win ratio.
Study context
- Population
- Simulated datasets of 300 individuals (control vs intervention with varying survival rates and ventilation durations) and four clinical trial datasets (LIVE, ARMA, ACURASYS, COVIDICUS)16 simulated datasets
- Comparison
- Twelve statistical methods for analysing ventilator-free days (VFDs)
- Outcome
- Statistical power and Type I error rate of methods for analysing VFDs
Methodological detailsapplication to 4 clinical trial datasets, sensitivity analyses
- Application to 4 clinical trial datasets
- Sensitivity analyses
Main finding
As reported in the abstract
- Most methods controlled Type I error rate, except zero-inflated and hurdle Poisson/negative binomial count submodels and cause-specific Cox regression for death
- Power to detect survival benefit and ventilation duration effects varied; time-to-event approaches, Mann-Whitney test, proportional odds model and win ratio generally best
Further findings
Sensitivity analyses
- Similar results
Real trial datasets
- Multistate model, Mann-Whitney test, proportional odds model and win ratio generally showed a significant association between VFDs and randomisation groups
Original publication
What is the optimal approach to analyse ventilator-free days? A simulation study. Crit Care. Published 19 June 2025. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →