Table 2.

Risk of colectomy in UC analysed by Cox regression. No. = number of patients included in the analysis.

Variables	No.	HR	CI	p-value	HR	CI	p-value
Female [ref.]	252	1.0
Male	267	0.9	0.6–1.6	0.9	Ni
Age at diagnosis
<40 years [ref.]	289	1.0
≥40 years	230	0.5	0.3–0.9	0.018	0.5	0.2–0.9	0.036
Extent at diagnosis
E1 [ref.]	171	1.0
E2	182	1.3	0.6–2.9	0.49	Excl.
E3	166	3.4	1.7–6.7	0.001	2.8	1.3–6.1	0.011
Biomarkers at diagnosis
ESR [mm/h] or CRP [mg/L]
<30 [ref.]	324	1.0
≥30	185	0.9	0.5–1.5	0.63	Ni
Systemic steroids at diagnosis
No [ref.]	357	1.0
Yes	161	1.2	0.7–2.0	0.60	Ni
Smoking status at diagnosis
Non-smoker [ref.]	448	1.0
Current smoker	69	0.5	0.2–1.4	0.18	Excl.
Mucosal healing at 1 year
No [ref.]	213	1.0			1.0
Yes	199	0.4	0.2–0.8	0.007	0.4	0.2–0.8	0.007

HR, hazard ratio; CI, 95% confidence interval; Ni, the variable was not entered in the multiple model; Excl, the variable was entered in the multiple models, but was excluded because of later non-significance; [ref.], reference category; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; UC ulcerative colitis.