Statistical analyses
The number of participants was calculated to detect an arbitrary median difference between groups of one recourse to a second-line method among the ten presented records. Given a two-sided test with 90% statistical power and 95% confidence interval (CI), 44 participants needed to be included. Based on this number and with the assumption that 10 to 15 more obstetricians would agree to participate after each monthly reminder, we decided to allow access to the online questionnaire for four months (July to October 2020).
Professional characteristics of the participants and attitudes towards the presented cases were compared between the two groups. Qualitative variables are presented as counts (percentages) and were compared between groups using the χ2 test or Fisher’s exact test when appropriate. Continuous variables are presented as the median (interquartile range [IQR]) and were compared using Student’s t-test or the Mann–Whitney U test when appropriate.
All of the statistical analyses were two-tailed, and the results were taken to be statistically significant when P values <0.05 were obtained. The analyses were performed using IBM SPSS Statistics version 20.0 (IBM Corporation, Armonk, New York, US).