2:4 Statistical analysis
We present results as number (percentages), mean (±standard deviation)
or median (interquartile range). We used Fischer-Freeman-Halton exact
test to compare proportions and Mann Whitney U test to compare means and
medians between the groups. Comparisons were made in SPSS version 28. To
calculate incidence rates (IR) for appendectomy for the years 2016-2020
we used numerators from the quality register [8] and denominator
from statistics Sweden. Estimates and confidence intervals for the IR
were done in open Epi version 3.01. A p -value < 0.05
was considered as a significant difference.