Table 2. Risk of fracture in patients with IBD.

Characteristics			Total No.	Fracture events	Duration (PY)	IR (per 1,000 PY)	HR (95% CI)
							Model 1	Model 2	Model 3	Model 4
Total fracture
	IBD
		Control	40,193	1,160	118,611.74	9.780	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)
		Case	9,855	333	28,851.15	11.542	1.18 (1.04–1.33)	1.29 (1.14–1.46)	1.31 (1.16–1.48)	1.31 (1.16–1.48)
	CD
		Control	6,786	204	19,559.68	10.430	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)
		Case	1,509	74	4,213.82	17.561	1.68 (1.28–2.19)	1.93 (1.48–2.52)	1.87 (1.43–2.44)	1.92 (1.47–2.52)
	UC
		Control	33,407	956	99,052.06	9.652	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)
		Case	8,346	259	24,637.33	10.513	1.09 (0.95–1.25)	1.17 (1.02–1.34)	1.20 (1.04–1.37)	1.19 (1.03–1.37)
Other fracture
	IBD
		Control	40,193	612	118,611.74	5.160	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)
		Case	9,855	155	28,851.15	5.372	1.04 (0.87–1.24)	1.10 (0.93–1.32)	1.12 (0.94–1.33)	1.12 (0.94–1.34)
	CD
		Control	6,786	110	19,559.68	5.624	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)
		Case	1,509	33	4,213.82	7.831	1.39 (0.94–2.05)	1.50 (1.02–2.22)	1.49 (1.01–2.20)	1.53 (1.03–2.28)
	UC
		Control	33,407	502	99,052.06	5.068	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)
		Case	8,346	122	24,637.33	4.952	0.98 (0.80–1.19)	1.03 (0.84–1.25)	1.04 (0.85–1.27)	1.04 (0.85–1.27)
Hip fracture
	IBD
		Control	40,193	64	118,611.74	0.540	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)
		Case	9,855	19	28,851.15	0.659	1.22 (0.73–2.04)	1.39 (0.83–2.33)	1.43 (0.86–2.39)	1.36 (0.81–2.28)
	CD
		Control	6,786	12	19,559.68	0.610	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)
		Case	1,509	3	4,213.82	0.712	1.16 (0.33–4.11)	1.51 (0.42–5.41)	1.35 (0.37–4.84)	1.14 (0.31–4.21)
	UC
		Control	33,407	52	99,052.06	0.525	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)
		Case	8,346	16	24,637.33	0.649	1.24 (0.71–2.17)	1.36 (0.78–2.38)	1.41 (0.80–2.48)	1.34 (0.76–2.37)
Vertebral fracture
	IBD
		Control	40,193	471	118,611.74	3.971	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)
		Case	9,855	157	28,851.15	5.441	1.37 (1.14–1.64)	1.55 (1.29–1.86)	1.58 (1.32–1.90)	1.59(1.33–1.92)
	CD
		Control	6,786	80	19,559.68	4.090	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)
		Case	1,509	37	4,213.82	8.781	2.14 (1.45–3.15)	2.59 (1.75–3.82)	2.50 (1.69–3.70)	2.60 (1.74–3.88)
	UC
		Control	33,407	391	99,052.06	3.947	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)	1.00 (Ref.)
		Case	8,346	120	24,637.33	4.871	1.23 (1.01–1.51)	1.37 (1.11–1.68)	1.41 (1.15–1.74)	1.42 (1.15–1.75)

Model 1: unadjusted analysis. Model 2: adjusted for age and sex. Model 3: adjusted for Model 2 + place of residence, income level, diabetes mellitus, hypertension, dyslipidemia and previous fracture within 5 years. Model 4: adjusted for Model 3 + body mass index, chronic kidney disease, current smoking, alcohol consumption and regular exercise.

CD = Crohn’s disease, CI = confidence interval, HR = hazard ratio, IBD = inflammatory bowel disease, IR = incidence rate, PY = person-years, Ref. = reference, UC = ulcerative colitis.