Twenty-eight studies were included in the review (13 RCTs and 15 observational studies). The number of patients could not be calculated, as the online supplementary material could not be located. Two RCTs reporting the secondary outcome scored 2 on quality and two RCTs scored 3. Three RCTs reported adequate methods for randomisation, none were double-blinded, none adequately described allocation concealment, and three reported withdrawals.
Studies reporting minor adverse events were clinically heterogeneous and the results could not be pooled. There were no statistically significant differences in the proportion of major adverse events between patients receiving propofol and those receiving midazolam (nine RCTs and 15 observational studies).
There was no statistically significant difference in the success rate for midazolam and propofol (four RCTs).
Sensitivity analyses did not significantly alter the results.