°chi-squared test; §t-test; ^Mann-Whitney test; PCG: pre-COVID group; CG: COVID group; BMI: body mass index; F: female; M: male; CCI: Charlson Comorbidity Index; ASA: America Society of Anaesthesiologists; WBC: white blood cells; CRP: C-reactive protein; AD: acute diverticulitis. Nominal data are expressed in number (%), continuous quantitative variables in mean±standard deviation; non-continuous variables in median and range. Here, CRP is linked to Alzheimer disease.