Table 1.

Patient demographics

Characteristics
Patients included, n	475
Male sex, n (%)	322 (67.8)
Age, years, median (IQR)	45 (33–58)
BMI, median (IQR)	26.1 (23.0–30.2)
Smoking status, n (%)
Never	163 (34.3)
Earlier	83 (17.5)
Active	166 (34.9)
Unknown	63 (13.3)
Alcohol, n (%)
Never	165 (34.7)
Earlier	13 (2.7)
Active	221 (46.5)
Unknown	74 (15.6)
Diabetes, n (%)	44 (9.3)
Type 1, n (%)	7 (1.5)
Type 2, n (%)	37 (7.8)
Inflammatory bowel disease, n (%)	29 (6.1)
Crohn’s disease, n (%)	25 (5.3)
Ulcerative colitis, n (%)	4 (0.8)
Preop. leucocyte count, median, billions/L (IQR)	11.6 (9.1–14.2)
Preop. CRP, median, mg/L (IQR)	30.0 (13.0–64.3)
Known with recurrent abscesses, n (%)	121 (25.5)
Known fistula disease, n (%)	37 (7.8)