Abstract
BACKGROUND: Clinicians’ decision-making regarding the use of noninvasive ventilation (NIV) after abdominal surgery requires evaluating the probability of a clinically meaningful benefit. The Bayesian framework may help caregivers interpret the findings of a randomized controlled trial (NIVAS) assessing curative NIV after abdominal surgery by incorporating their prior beliefs, yielding more precise estimates of treatment effects. This study aimed to use a Bayesian framework to estimate posterior probabilities of NIV effect under various prior assumptions, reflecting diverse clinicians’ beliefs. METHOD: A prospectively registered, post-hoc Bayesian reanalysis of the NIVAS multicenter trial was conducted. The study included 293 patients with acute respiratory failure following abdominal surgery who were randomly assigned to receive either conventional oxygen therapy or NIV. Four statistical priors were defined: minimally informative, skeptical, enthusiastic, and pessimistic, reflecting a range of clinical beliefs. The primary outcome was day-7 reintubation. Secondary outcomes included day-30 mortality. Effect sizes were presented as odds ratios (OR) and absolute risk reduction (ARR) with 95% credible intervals (CrI). RESULTS: The minimally informative prior resulted in a posterior median OR for day-7 reintubation of 0.59 (95% CrI 0.37 to 0.95) in favor of NIV. Under the pessimistic prior, the posterior median OR was 0.64 (95% CrI 0.40 to 1.00). The posterior probability that NIV is superior to oxygen therapy varied from 96 to 99% across various priors, from pessimistic to enthusiastic. The probability of benefit beyond an ARR ≥ 5% ranged from 77 to 93%. Regarding day-30 mortality, the posterior median OR was 0.63 (95% CrI 0.32 to 1.31) under minimally informative prior and 0.79 (95% CrI 0.48 to 1.29) under the skeptical prior. The probability of NIV superiority ranged from 82 to 90%. CONCLUSION: This Bayesian trial re-analysis indicates that NIV has a high probability of achieving a clinically meaningful reduction in day 7 reintubation, even under pessimistic prior beliefs. These results suggest that use of NIV to treat respiratory failure after abdominal surgery is reasonable. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13054-025-05795-9.