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).