Statistical analyses
The study population was described using means and standard deviations
(SD) for quantitative variables with normal distribution or medians and
minimal/maximal values [min; max] otherwise. Frequencies and their
associated percentage were used for qualitative variables. The normal
distribution of continuous variables was explored graphically.
Quantitative variables were compared using Student’s t-test when the
distribution was Gaussian, or the Mann-Whitney test otherwise. For
qualitative variables, groups were compared using the chi-squared test
or Fisher’s exact test. The statistical significance was set at 0.05 and
analyses were performed using Excel® software.