Trends in medication use and treatment patterns in Chinese patients with inflammatory bowel disease

Table 2 Comparison of demographic and clinical characteristics of patients with inflammatory bowel disease included and excluded from analysis in 1999-2020

	Excluded (n = 2653)	Included (n = 957)	P value
Male sex, n (%)	1268 (47.8)	398 (41.6)	0.0009
Median age of onset (IQR), yr	32.0 (23.0-46.0)	30.0 (22.0-41.0)	< 0.001
Median age at diagnosis (IQR), yr	35.0 (25.0-49.0)	32.0 (24.0-44.0)	< 0.001
Median interval from onset to diagnosis (IQR), mo	12.2 (2.4-36.6)	12.2 (2.4-32.9)	0.3270
Smoking status at diagnosis, n (%)			0.0005
Non-smoker	2067 (77.9)	793 (82.8)
Current smoker	273 (10.3)	83 (8.7)
Former smoker	174 (6.6)	59 (6.2)
Unknown	139 (5.2)	22 (2.3)
Region of urbanization, n (%)			0.0411
City	1450 (54.7%)	509 (53.2)
Rural	1164 (43.9)	443 (46.3)
Unknown	39 (1.4)	5 (0.5)
Occupation, n (%)			< 0.0001
Unemployed	371 (14.0)	124 (12.9)
Employed	1226 (46.2)	625 (65.3)
Student	272 (10.2)	105 (11.0)
Retire	201 (7.6)	57 (6.0)
Unknown	583 (22.0)	46 (4.8)
BMI category at diagnosis, n (%)			< 0.0001
Normal	694 (26.1)	320 (33.4)
Underweight	1100 (41.5)	424 (44.4)
Overweight + Obese	278 (10.5)	101 (10.6)
Unknown	580 (21.9)	111 (11.6)
Disease location, n (%)
L1—ileal location	441 (29.1)	185 (27.0)	0.3722
L2—colon location	158 (10.4)	66 (9.6)
L3—ileocolon location	768 (50.6)	374 (54.6)
L4—including upper GI location	151 (9.9)	60 (8.8)
E1—proctitis	156 (13.8)	45 (16.6)	0.0005
E2—left-sided	360 (31.8)	98 (36.2)
E3—extensive colitis	534 (47.2)	126 (46.5)
Unknown	81 (7.2)	2 (0.7)
Disease activity (CDAI), n (%)			0.0002
Remission	75 (4.9)	25 (3.6)
Mild	314 (20.6)	103 (15.0)
Moderate	748 (49.1)	408 (59.5)
Severe	136 (9.0)	52 (7.6)
Unknown	249 (16.4)	98 (14.3)
Disease activity (Mayo), n (%)			< 0.0001
Remission	18 (1.6)	4 (1.5)
Mild	231 (20.4)	71 (26.2)
Moderate	406 (35.9)	121 (44.7)
Severe	192 (17.0)	60 (22.1)
Unknown	284 (25.1)	15 (5.5)
Disease behavior (CD), n (%)			0.4273
B1—inflammatory disease	797 (52.5)	378 (55.2)
B2—stricturing disease	488 (32.1)	202 (29.5)
B3—penetrating disease	233 (15.4)	105 (15.3)
Perianal involvement (CD), n (%)			0.0800
Fistula	524 (34.4)	248 (36.2)
Abscess	262 (17.2)	130 (19.0)
Fissure	24 (1.6)	14 (2.0)
Extraintestinal manifestations, n (%)	318 (12.0)	146 (15.3)	0.0096
Family history, n (%)	19 (0.7)	8 (0.8)	0.7124
History of gastrointestinal surgery, n (%)	423 (15.9)	171 (17.9)	0.1687
History of perianal surgery, n (%)	263 (9.9)	208 (21.7)	< 0.0001
Medication use within 6 mo before diagnosis, n (%)	646 (24.3)	262 (27.4)	0.0643

The classification of body mass index: Underweight: < 18.5; Normal: 18.5-23.9; Overweight: 24-28; Obese > 28. Disease behavior was not available in 1407 patients. IQR: Interquartile ranges; BMI: Body mass index; CDAI: Crohn’s disease Activity Index; CD: Crohn’s Disease.