Statistical analyses
Continuous variables are expressed as mean ± standard deviation for
normal distribution and as median and interquartile range in case of
skewed distribution. Categorical data are expressed as number and
percentages. To compare proportions of patients with at least 1 episode
in the two periods of comparison (reference and lockdown periods) we
used a test for categorical dependent samples (McNemar). To assess
differences in numbers of events over the two periods of interest
(reference and lockdown periods) we used a non-parametric paired samples
test (Wilcoxon). A two-sided p-value of less than 0.05 was considered
significant. Statistical analyses were undertaken using SPSS version 22
(IBM SPSS Statistics).
Observation time was divided in 3 periods: lockdown period (March 9
through May 4, 2020) with the corresponding reference period in 2019
(March 9 through May 4, 2019) with a global observation period of 16
months (January 1, 2019 to May 4, 2020). We compared cardiac arrhythmias
rate during lockdown period (March
9 through May 4, 2020) to the corresponding reference period in 2019.