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

Table 1 Demographic and clinical characteristics of patients with inflammatory bowel disease in 1999-2020

	Total (n = 3610)	CD (n = 2208)	UC (n = 1402)	P value
Male sex, n (%)	1666 (46.2)	935 (42.3)	731 (52.1)	< 0.0001
Median age of onset (IQR), yr	31.0 (23.0-45.0)	27.0 (21.0-37.0)	42.0 (30.0-54.0)	< 0.0001
Median age at diagnosis (IQR), yr	33.0 (25.0-48.0)	29.0 (23.0-39.0)	45.0 (32.0-56.0)	< 0.0001
Median interval from onset to diagnosis (IQR), mo	12.2 (2.4-36.5)	12.4 (3.7-36.7)	6.17 (1.2-26.4)	< 0.0001
Median duration of follow-up (IQR), yr	1.6 (0.3-3.8)	2.0 (0.8-3.9)	0.7 (0.1-3.2)	< 0.0001
Smoking status at diagnosis, n (%)				< 0.0001
Non-smoker	2860 (79.2)	1828 (82.8)	1032 (73.6)
Current smoker	356 (9.9)	198 (9.0)	158 (11.3)
Former smoker	233 (6.4)	114 (5.2)	119 (8.5)
Unknown	161 (4.5)	68 (3.0)	93 (6.6)
Region of urbanization, n (%)				0.7918
Rural	1607 (44.5)	991 (44.9)	616 (43.9)
Urban	1959 (54.3)	1189 (53.8)	770 (54.9)
Unknown	44 (1.2)	28 (1.3)	16 (1.2)
Occupation, n (%)				< 0.0001
Unemployed	495 (13.7)	316 (14.3)	179 (12.8)
Employed	1851 (51.3)	1227 (55.6)	624 (44.5)
Student	377 (10.5)	334 (15.1)	43 (3.1)
Retire	258 (7.1)	95 (4.3)	163 (11.6)
Unknown	629 (17.4)	236 (10.7)	393 (28.0)
BMI category at diagnosis, n (%)				< 0.0001
Normal	1014 (28.1)	812 (36.8)	202 (14.4)
Underweight	1524 (42.2)	912 (41.3)	612 (43.7)
Overweight + Obese	379 (10.5)	183 (8.3)	196 (14.0)
Unknown	691 (19.2)	300 (13.6)	391 (27.9)
Disease location, n (%)
L1—ileal location	-	626 (28.4)	-
L2—colon location		224 (10.2)
L3—ileocolon location		1142 (51.8)
L4—including upper GI location		211 (9.6)
E1—proctitis		-	201 (14.3)
E2—left-sided			458 (32.7)
E3—extensive colitis			660 (47.1)
Unknown			83 (5.9)
Disease activity (CDAI/Mayo), n (%)
Remission	122 (3.4)	100 (4.5)	22 (1.6)
Mild	719 (19.9)	417 (18.9)	302 (21.5)
Moderate	1683 (46.6)	1156 (52.4)	527 (37.6)
Severe	440 (12.2)	188 (8.5)	252 (18.0)
Unknown	646 (17.9)	347 (15.7)	299 (21.3)
Disease behavior, n (%)
B1—inflammatory disease	-	1175 (53.3)	-
B2—stricturing disease		690 (31.3)
B3—penetrating disease		338 (15.4)
Perianal involvement, n (%)
Fistula	-	772 (35.0)	-
Abscess		392 (17.8)
Fissure		38 (1.7)
Extraintestinal manifestations, n (%)	464 (12.9)	357 (16.2)	107 (7.6)	< 0.0001
Family history of IBD, n (%)	27 (0.7)	20 (0.9)	7 (0.5)	0.1671
History of gastrointestinal surgery, n (%)	594 (16.5)	524 (23.7)	70 (5.0)	< 0.0001
History of perianal surgery, n (%)	471 (13.0)	471 (21.3)	0 (0.0)	< 0.0001
Medication use before diagnosis (≤ 6 mo), n (%)	908 (25.2)	440 (19.9)	468 (33.4)	< 0.0001

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 5 patients. IBD: Inflammatory bowel disease; CD: Crohn’s disease; UC: Ulcerative colitis; IQR: Interquartile ranges; BMI: Body mass index; CDAI: Crohn’s Disease Activity Index.

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.

Table 3 Influencing factors of initial drug strategies in patients with Crohn’s disease

	CS (n = 132)		CS + IMS (n = 203)		IFX (n = 728)
	OR (95%CI)	P value	OR (95%CI)	P value	OR (95%CI)	P value
Sex
Female	Ref	—	Ref	—	Ref	—
Male	0.86 (0.57-1.29)	0.4577	0.49 (0.33-0.73)	0.0005	0.89 (0.70-1.13)	0.3295
Age of onset	1.02 (0.95-1.10)	0.5165	1.01 (0.93-1.09)	0.8581	0.99 (0.95-1.02)	0.4621
Age at diagnosis	1.00 (0.93-1.08)	0.9428	0.99 (0.92-1.07)	0.8167	0.98 (0.95-1.02)	0.3752
Smoking status at diagnosis
Non-smoker	Ref	—	Ref	—	Ref	—
Current smoker	0.91 (0.49-1.71)	0.7754	0.86 (0.48-1.54)	0.6041	0.64 (0.42-0.99)	0.0452
Former smoker	0.65 (0.26-1.62)	0.3560	0.66 (0.30-1.43)	0.2900	0.47 (0.28-0.81)	0.0062
Unknown	1.30 (0.46-3.71)	0.6211	NS	NS	1.11 (0.62-1.99)	0.7192
Region of urbanization
Rural	Ref	—	Ref	—	Ref	—
Urban	0.60 (0.40-0.89)	0.0117	0.49 (0.34-0.69)	< 0.0001	1.07 (0.85-1.35)	0.5761
Unknown	NS	NS	NS	NS	1.84 (0.76-4.49)	0.1794
Occupation
Unemployed	Ref	—	Ref	—	Ref	—
Employed	1.27 (0.72-2.23)	0.4031	1.01 (0.62-1.63)	0.9826	1.11 (0.78-1.58)	0.5578
Student	1.27 (0.53-3.05)	0.5960	0.98 (0.49-1.95)	0.9539	1.61 (1.02-2.53)	0.0408
Retire	0.62 (0.21-1.84)	0.3916	0.56 (0.16-1.94)	0.3619	1.74 (0.85-3.54)	0.1267
Unknown	0.46 (0.19-1.11)	0.0830	NS	NS	0.86 (0.54-1.37)	0.5216
BMI category at diagnosis
Normal	Ref	—	Ref	—	Ref	—
Underweight	1.30 (0.83-2.04)	0.2498	0.88 (0.60-1.30)	0.5295	0.92 (0.71-1.21)	0.5645
Overweight + Obese	0.56 (0.25-1.26)	0.1601	0.42 (0.20-0.88)	0.0204	0.47 (0.30-0.73)	0.0008
Unknown	0.46 (0.23-0.94)	0.0320	0.14 (0.04-0.46)	0.0012	0.81 (0.57-1.14)	0.2241
Disease location
L1—ileal location	Ref	—	Ref	—	Ref	—
L2—colon location	0.81 (0.41-1.57)	0.5317	0.74 (0.35-1.55)	0.4201	0.94 (0.63-1.43)	0.7869
L3—ileocolon location	0.58 (0.37-0.90)	0.0162	1.05 (0.69-1.61)	0.8105	1.12 (0.85-1.46)	0.4211
L4—including upper GI location	0.69 (0.31-1.56)	0.3708	1.91 (1.02-3.57)	0.0438	1.88 (1.20-2.96)	0.0061
Disease activity (CDAI)
Remission	Ref	—	Ref	—	Ref	—
Mild	0.84 (0.28-2.51)	0.7498	2.17 (0.84-5.61)	0.1091	1.44 (0.79-2.63)	0.2346
Moderate	1.56 (0.57-4.33)	0.3888	2.35 (0.94-5.86)	0.0664	2.08 (1.18-3.69)	0.0118
Severe	0.77 (0.19-3.04)	0.7050	0.46 (0.08-2.53)	0.3710	1.62 (0.83-3.16)	0.1576
Unknown	1.37 (0.45-4.15)	0.5791	0.88 (0.28-2.78)	0.8290	1.05 (0.56-1.98)	0.8746
Disease behavior
B1—inflammatory disease	Ref	—	Ref	—	Ref	—
B2—stricturing disease	0.82 (0.53-1.27)	0.3734	0.99 (0.67-1.47)	0.9531	0.63 (0.48-0.83)	0.0008
B3—penetrating disease	0.22 (0.10-0.48)	< 0.001	0.12 (0.05-0.30)	< 0.0001	0.39 (0.28-0.56)	< 0.0001
Extraintestinal manifestations
No	Ref	—	Ref	—	Ref	—
Yes	1.10 (0.65-1.87)	0.7105	1.88 (1.23-2.87)	0.0037	0.93 (0.67-1.28)	0.6605
Family history of IBD
No	Ref	—	Ref	—	Ref	—
Yes	1.46 (0.14-15.30)	0.7514	1.70 (0.22-13.10)	0.6104	1.67 (0.37-7.62)	0.5082
History of gastrointestinal surgery
No	Ref	—	Ref	—	Ref	—
Yes	0.35 (0.20-0.60)	0.0002	0.35 (0.20-0.59)	< 0.0001	0.55 (0.41-0.73)	< 0.0001
History of perianal surgery
No	Ref	—	Ref	—	Ref	—
Yes	1.36 ( 0.77-2.40)	0.2948	1.86 (1.20-2.87)	0.0052	2.68 (1.92-3.73)	< 0.0001
Medication use before diagnosis (≤ 6 mo)
No	Ref	—	Ref	—	Ref	—
Yes	1.94 (1.16-3.23)	0.0111	3.06 (2.04-4.58)	< 0.0001	1.33 (0.95-1.85)	0.0934
Calendar year of diagnosis
< 2009	Ref	—	Ref	—	Ref	—
≥ 2009	0.19 (0.09-0.40)	< 0.0001	0.77 (0.25-2.33)	0.6393	NS	NS

CS: Corticosteroids; IMS: Immunosuppressants; IFX: Infliximab; OR: Odd ratio; CI: Confidence interval; BMI: Body mass index; CDAI: Crohn’s Disease Activity Index; IBD: Inflammatory bowel disease; NS: Non-significant.

Table 4 Influencing factors of initial drug strategy in patients with ulcerative colitis

	5-ASA (n = 566)		CS (n = 213)		IFX/IMS (n = 43)
	OR (95%CI)	P value	OR (95%CI)	P value	OR (95%CI)	P value
Sex
Female	Ref	—	Ref	—	Ref	—
Male	1.02 (0.78-1.34)	0.8770	0.90 (0.63-1.27)	0.5397	0.98 (0.50-1.92)	0.9493
Age of onset	0.98 (0.95-1.02)	0.4057	1.03 (0.97-1.09)	0.3654	0.93 (0.87-0.99)	0.0233
Age at diagnosis	1.02 (0.98-1.05)	0.3876	0.96 (0.91-1.02)	0.1792	1.04 (0.98-1.10)	0.2434
Smoking status at diagnosis
Non-smoker	Ref	—	Ref	—	Ref	—
Current smoker	0.64 (0.41-1.00)	0.0490	0.67 (0.38-1.18)	0.1651	0.94 (0.32-2.79)	0.9156
Former smoker	0.76 (0.46-1.25)	0.2812	0.87 (0.45-1.67)	0.6713	2.04 (0.72-5.78)	0.1777
Unknown	3.39 (1.83-6.27)	0.0001	1.15 (0.42-3.19)	0.7864	3.42 (0.62-18.90)	0.1583
Region of urbanization
Rural	Ref	—	Ref	—	Ref	—
Urban	0.80 (0.60-1.07)	0.1311	0.82 (0.57-1.19)	0.2945	1.03 (0.51-2.08)	0.9245
Unknown	0.11 (0.02-0.64)	0.0138	0.23 (0.02-2.21)	0.2010	NS	NS
Occupation
Unemployed	Ref	—	Ref	—	Ref	—
Employed	2.85 (1.79-4.55)	< 0.001	1.23 (0.74-2.06)	0.4241	0.93 (0.34-2.53)	0.8866
Student	1.06 (0.39-2.87)	0.9159	0.57 (0.19-1.71)	0.3178	0.78 (0.12-5.10)	0.7976
Retire	2.39 (1.31-4.35)	0.0043	1.14 (0.55-2.39)	0.7216	2.02 (0.52-7.91)	0.3135
Unknown	2.07 (1.15-3.70)	0.0145	0.73 (0.36-1.46)	0.3691	1.93 (0.60-6.19)	0.2697
BMI category at diagnosis
Normal	Ref	—	Ref	—	Ref	—
Underweight	0.85 (0.55-1.31)	0.4669	1.22 (0.74-2.03)	0.4325	0.90 (0.36-2.22)	0.8136
Overweight + Obese	1.10 (0.73-1.64)	0.6532	0.52 (0.28-0.99)	0.0455	0.49 (0.14-1.77)	0.2757
Unknown	0.78 (0.55-1.12)	0.1742	0.78 (0.49-1.23)	0.2900	0.42 (0.16-1.11)	0.0785
Disease location
E1—proctitis	Ref	—	Ref	—	Ref	—
E2—left-sided	1.18 (0.78-1.78)	0.4254	1.67 (0.82-3.38)	0.1585	2.57 (0.54-12.20)	0.2331
E3—extensive colitis	1.58 (1.05-2.38)	0.0288	3.06 (1.54-6.08)	0.0014	2.93 (0.63-13.60)	0.1695
Unknown	4.41 (1.95-9.97)	0.0004	3.99 (1.23- 12.9)	0.0209	NS	NS
Disease activity (MAYO)
Remission	Ref	—	Ref	—	Ref	—
Mild	0.65 (0.22-1.92)	0.4374	1.04 (0.11-9.97)	0.9697	0.35 (0.03-3.86)	0.3905
Moderate	0.76 (0.26-2.22)	0.6156	2.99 (0.33-27.10)	0.3292	0.57 (0.06-5.61)	0.6308
Severe	0.32 (0.10-0.97)	0.0442	6.51 (0.71-59.60)	0.0972	1.91 (0.19-19.00)	0.5798
Unknown	0.39 (0.13-1.22)	0.1061	1.57 (0.16-15.30)	0.6994	0.09 (0.01-1.24)	0.0716
Extraintestinal manifestations
No	Ref	—	Ref	—	Ref	—
Yes	0.74 (0.41-1.31)	0.2993	1.94 (1.07-3.51)	0.0287	1.83 (0.72-4.62)	0.2025
Family history of IBD
No	Ref	—	Ref	—	Ref	—
Yes	0.68 (0.09-4.94)	0.7041	0.87 (0.08-10.00)	0.9096	NS	NS
History of gastrointestinal surgery
No	Ref	—	Ref	—	Ref	—
Yes	0.68 (0.36-1.26)	0.2163	0.57 (0.25-1.31)	0.1824	0.88 (0.18-4.23)	0.8683
Medication use before diagnosis (≤ 6 mo)
No	Ref	—	Ref	—	Ref	—
Yes	10.2 (7.19-14.5)	< 0.0001	7.23 (4.71-11.10)	< 0.0001	9.88 (4.77-20.50)	< 0.0001
Calendar year of diagnosis
< 2009	Ref	—	Ref	—	Ref	—
≥ 2009	0.31 (0.22-0.45)	< 0.0001	0.51 (0.30-0.85)	0.0097	3.12 (0.41-23.90)	0.2748

5-ASA: 5-aminosalicylates; CS: Corticosteroids; IMS: Immunosuppressants; IFX: Infliximab; OR: Odd ratio; CI: Confidence interval; BMI: Body mass index; NS: Non-significant; IBD: Inflammatory bowel disease.