Statistical analysis
sepsis
REGRESSION, SEPSIS, ACUTE PANCREATITIS, PERIPANCREATIC NECROSIS
Analyses were performed in the intention-to-treat population, i.e., all patients randomized except those who had withdrawn consent or did not retrospectively meet inclusion criteria. For the primary analysis, we used a Mann–Whitney U test and computed effect-sizes or absolute median differences with 95% confidence intervals (CIs). Given that a high proportion of patients never required intubation (i.e., had 30 ventilator-free days), we performed post-hoc zero-inflated negative binomial regression to estimate the odds ratio for having 30 ventilator-free days and the incident rate ratio for the number of ventilator-free days (when not equal to 30), before and after adjustment for the randomization-stratification variables, including site as random effect.Analyses of the primary outcome were also performed in the per-protocol population, as defined by all randomized patients, except for patients who withdrew their consent or did not meet the inclusion criteria, including those assigned to the intervention group who received epidural analgesia for less than 72 h. Post-hoc subgroup analyses of the primary outcome based on potential risk factors of worse outcome of acute pancreatitis were performed (including randomization-stratification variables, the need for vasopressor support or intubation at baseline, the presence of sepsis or peripancreatic necrosis at baseline, age, and serum C-reactive protein at baseline) using unadjusted zero-inflated negative binomial regression and testing for heterogeneity between subgroups in the number of ventilator-free days by fitting an interaction between treatment and subgroup.Secondary outcomes were analyzed as described in the statistical analysis plan (see Additional file 