Background
Methods
Patients
Study design
Study objectives
Study evaluations
Statistical analysis
Ethical considerations
Results
Enrollment and demographic characteristics
Variable | Total | Inland city | Coastal city | P value |
---|---|---|---|---|
N (%) | 499 | 191 (38.3%) | 308 (61.7%) | |
Age at enrollment (years), mean (SD) | 32.3 (11.43) | 34.3 (13.03) | 31.1 (10.14) | 0.0022 |
Male, n (%) | 348 (69.7%) | 138 (72.3%) | 210 (68.2%) | |
Ethnicity, n (%) | ||||
Chinese Han | 495 (99.2%) | 187 (97.9%) | 308 (100.0%) | |
Other Chinese minority | 4 (0.8%) | 4 (2.1%) | 0 | |
BMI (kg/m2), mean (SD) | 19.10 (3.198) | 18.80 (2.676) | 19.29 (3.479) | |
Nicotine use history, n (%) | 0.0036 | |||
N | 442 | 165 | 277 | |
Never used | 382 (86.4%) | 132 (80.0%) | 250 (90.3%) | |
Current user | 36 (8.1%) | 17 (10.3%) | 19 (6.9%) | |
Former user | 24 (5.4%) | 16 (9.7%) | 8 (2.9%) | |
Alcohol use history, n (%) | 0.0023 | |||
N | 443 | 166 | 277 | |
Never used | 401 (90.5%) | 143 (86.1%) | 258 (93.1%) | |
Current user | 22 (5.0%) | 8 (4.8%) | 14 (5.1%) | |
Former user | 20 (4.5%) | 15 (9.0%) | 5 (1.8%) | |
Medical history reported, n (%) | ||||
Any medical history | 180 (36.1%) | 76 (39.8%) | 104 (33.8%) | |
Hepatitis B | 19 (3.8%) | 7 (3.7%) | 12 (3.9%) | |
Appendicitis | 10 (2.0%) | 5 (2.6%) | 5 (1.6%) | |
Hypertension | 8 (1.6%) | 3 (1.6%) | 5 (1.6%) | |
Nephrolithiasis | 10 (2.0%) | 7 (3.7%) | 3 (1.0%) | |
CD-related surgery history, n (%) | 119 (23.8%) | 51 (26.7%) | 68 (22.1%) | 0.2071 |
Perianal disease related surgery, n (%) | 79 (15.8%) | 21 (11.0%) | 58 (18.8%) | 0.0023 |
Family history of IBD, n (%) | ||||
N | 6 | 2 | 4 | |
Crohn’s disease | 5 (83.3%) | 2 (100%) | 3 (75.0%) | |
Ulcerative colitis | 1 (16.7%) | 0 | 1 (25.0%) | |
Age at disease onset (years), n (%) | 0.0291 | |||
≤ 16 | 29 (5.8%) | 15 (7.9%) | 14 (4.5%) | |
17–39 | 401 (80.4%) | 142 (74.3%) | 259 (84.1%) | |
≥ 40 | 69 (13.8%) | 34 (17.8%) | 35 (11.4%) | |
Age at initial diagnosis (years), n (%) | 0.0083 | |||
≤ 16 | 6 (1.2%) | 4 (2.1%) | 2 (0.6%) | |
17–39 | 418 (83.8%) | 148 (77.5%) | 270 (87.7%) | |
≥ 40 | 75 (15.0%) | 39 (20.4%) | 36 (11.7%) | |
Time from disease onset to initial diagnosis (months), mean (SD) | 32.0 (46.43) | 39.9 (58.84) | 27.0 (35.93) | 0.0255 |
Location, n (%) | < 0.0001 | |||
N | 493 | 190 | 303 | |
L1 | 137 (27.8%) | 69 (36.3%) | 68 (22.4%) | |
L2 | 71 (14.4%) | 38 (20.0%) | 33 (10.9%) | |
L3 | 277 (56.2%) | 82 (43.2%) | 195 (64.4%) | |
L4 | 8 (1.6%) | 1 (0.5%) | 7 (2.3%) | |
Behavior, n (%) | < 0.0001 | |||
N | 495 | 190 | 305 | |
B1 | 247 (49.9%) | 110 (57.9%) | 137 (44.9%) | |
B2 | 148 (29.9%) | 45 (23.7%) | 103 (33.8%) | |
B3 | 100 (20.2%) | 35 (18.4%) | 65 (21.3%) | |
Perianal disease | 144 (29.1%) | 32 (16.8%) | 112 (36.7%) | |
Crohn’s Disease Activity Index at baseline, n (%) | 0.0094 | |||
N | 165 | 80 | 85 | |
< 150 | 81 (49.1%) | 37 (46.3%) | 44 (51.8%) | |
150–220 | 43 (26.1%) | 28 (35.0%) | 15 (17.6%) | |
221–400 | 39 (23.6%) | 13 (16.3%) | 26 (30.6%) | |
> 400 | 2 (1.2%) | 2 (2.5%) | 0 | |
Crohn’s disease treatment information at baseline, n (%) | ||||
Any Crohn’s disease treatment | 441 (88.4%) | 161 (84.3%) | 280 (90.9%) | 0.0308 |
Immunomodulators | 207 (41.5%) | 78 (40.8%) | 129 (41.9%) | 0.8179 |
Anti-TNF agents | 164 (32.9%) | 50 (26.2%) | 114 (37.0%) | 0.0123 |
Aminosalicylates | 103 (20.6%) | 47 (24.6%) | 56 (18.2%) | 0.0847 |
Steroids | 99 (19.8%) | 53 (27.7%) | 46 (14.9%) | 0.0005 |
Enteral nutrition | 69 (13.8%) | 6 (3.1%) | 63 (20.5%) | < 0.0001 |
Antibiotics | 65 (13.0%) | 6 (3.1%) | 59 (19.2%) | < 0.0001 |
Anti-tuberculosis | 27 (5.4%) | 1 (0.5%) | 26 (8.4%) | < 0.0001 |
Anti-hepatitis | 3 (0.6%) | 2 (1.0%) | 1 (0.3%) | 0.5613 |
Other agentsa | 115 (23.0%) | 7 (3.7%) | 108 (35.1%) | < 0.0001 |
Time from disease onset to definite diagnosis
Year of disease onset | n | Age (years) at disease onseta | Months from disease onset to definite diagnosisb |
---|---|---|---|
Before 2010 | 130 | 27.0 (10.82) | 79.4 (67.03) |
2010 | 34 | 28.1 (11.73) | 39.4 (24.11) |
2011 | 38 | 26.4 (10.65) | 28.7 (20.81) |
2012 | 41 | 28.6 (10.07) | 21.0 (13.57) |
2013 | 74 | 26.3 (8.48) | 17.3 (8.99) |
2014 | 104 | 28.7 (10.74) | 7.7 (5.41) |
2015 | 78 | 30.5 (11.53) | 3.1 (2.13) |
Surgery history
Variable | Total | Patients with surgery history | Patients without surgery history | P value |
---|---|---|---|---|
N (%) | 499 | 119 (23.8%) | 380 (76.2%) | |
Age (years), mean (SD) | 32.3 (11.43) | 37.3 (11.95) | 30.8 (10.81) | < 0.0001 |
Male, n (%) | 348 | 91 (76.5%) | 257 (67.6%) | 0.0670 |
BMI (kg/m2), mean (SD) | 19.10 (3.198) | 18.81 (3.119) | 19.19 (3.223) | 0.3898 |
Age at disease onset (years), mean (SD) | 27.9 (10.63) | 30.8 (10.98) | 27.0 (10.37) | 0.0006 |
Age group at disease onset (years), n (%) | 0.0007 | |||
N | 499 | 119 | 380 | |
≤ 16 | 29 (5.8%) | 6 (5.0%) | 23 (6.1%) | |
17–39 | 401 (80.4%) | 84 (70.6%) | 317 (83.4%) | |
≥ 40 | 69 (13.8%) | 29 (24.4%) | 40 (10.5%) | |
Age at initial definite diagnosis (years), mean (SD) | 30.6 (11.01) | 34.1 (11.45) | 29.5 (10.66) | < 0.0001 |
Time from disease onset to initial diagnosis (months), mean (SD) | 32.0 (46.43) | 39.4 (47.57) | 29.6 (45.89) | 0.0457 |
Time from initial diagnosis to enrollment (months), mean (SD) | 20.6 (39.06) | 39.3 (61.42) | 14.8 (26.24) | < 0.0001 |
Time from disease onset to enrollment (months), mean (SD) | 52.6 (59.08) | 78.6 (73.29) | 44.4 (51.32) | < 0.0001 |
Nicotine use history, n (%) | 0.4698 | |||
N | 442 | 99 | 343 | |
Never used | 382 (86.4%) | 83 (83.8%) | 299 (87.2%) | |
Current user | 36 (8.1%) | 11 (11.1%) | 25 (7.3%) | |
Former user | 24 (5.4%) | 5 (5.1%) | 19 (5.5%) | |
Alcohol use history, n (%) | 0.0760 | |||
N | 443 | 99 | 344 | |
Never used | 401 (90.5%) | 84 (84.8%) | 317 (92.2%) | |
Current user | 22 (5.0%) | 8 (8.1%) | 14 (4.1%) | |
Former user | 20 (4.5%) | 7 (7.1%) | 13 (3.8%) | |
Location, n (%) | 0.4628 | |||
N | 493 | 115 | 378 | |
L1 | 137 (27.8%) | 27 (23.5%) | 110 (29.1%) | |
L2 | 71 (14.4%) | 21 (18.3%) | 50 (13.2%) | |
L3 | 277 (56.2%) | 65 (56.5%) | 212 (56.1%) | |
L4 | 8 (1.6%) | 2 (1.7%) | 6 (1.6%) | |
Behavior, n (%) | < 0.0001 | |||
N | 495 | 115 | 380 | |
B1 | 247 (49.9%) | 27 (23.5%) | 220 (57.9%) | |
B2 | 148 (29.9%) | 38 (33.0%) | 110 (28.9%) | |
B3 | 100 (20.2%) | 50 (43.5%) | 50 (13.2%) | |
Perianal disease, n (%) | 144 (28.9%) | 20 (16.8%) | 124 (32.6%) | 0.0009 |
Variable | OR | 95% CI for OR | Parameter estimates (standard error) | Corresponding 95% CI | P value |
---|---|---|---|---|---|
Age (years) | 1.047 | 1.029, 1.066 | 0.046 (0.009)+ | 0.029, 0.064 | < 0.001* |
Sex (male vs. female) | 1.549 | 0.963, 2.491 | 0.438 (0.242)+ | −0.037, 0.913 | 0.071 |
BMI (18.5 - < 24 vs. < 18.5 kg/m2) | 0.845 | 0.482, 1.481 | −0.169 (0.287) | −0.731, 0.393 | 0.555 |
BMI (≥24 vs. < 18.5 kg/m2) | 0.713 | 0.225, 2.260 | − 0.339 (0.589) | −1.493, 0.815 | 0.565 |
Nicotine use (former vs. Never) | 0.951 | 0.345, 2.624 | −0.050 (0.518) | −1.065, 0.965 | 0.923 |
Nicotine use (current vs. Never) | 1.591 | 0.752, 3.367 | 0.464 (0.382)+ | −0.285, 1.214 | 0.225 |
Alcohol use (former vs. Never) | 2.038 | 0.789, 5.270 | 0.712 (0.485)+ | −0.238, 1.662 | 0.142 |
Alcohol use (current vs. Never) | 2.163 | 0.878, 5.328 | 0.772 (0.460)+ | −0.130, 1.673 | 0.093 |
Time from disease onset to enrollment (months) | 1.009 | 1.005, 1.013 | 0.009 (0.002)+ | 0.005, 0.012 | < 0.001* |
Time from initial definite diagnosis to enrollment (months) | 1.015 | 1.009, 1.021 | 0.015 (0.003)+ | 0.009, 0.021 | < 0.001* |
Disease behavior (B2 vs. B1) | 2.815 | 1.634, 4.848 | 1.035 (0.278)+ | 0.491, 1.579 | < 0.001* |
Disease behavior (B3 vs. B1) | 8.147 | 4.655, 14.261 | 2.098 (0.286)+ | 1.538, 2.658 | < 0.001* |
Disease behavior (B3 vs. B2) | 2.895 | 1.690, 4.959 | 1.063 (0.275)+ | 0.525, 1.601 | < 0.001* |
Disease location (L3 vs. L1) | 1.260 | 0.761, 2.087 | 0.231 (0.257) | −0.273, 0.736 | 0.368 |
Disease location (L3 vs. L2) | 0.730 | 0.408, 1.304 | −0.315 (0.296)+ | −0.895, 0.266 | 0.288 |
Perianal disease (yes vs. no) | 0.419 | 0.247, 0.709 | −0.871 (0.268)+ | −1.397, − 0.344 | 0.001* |
Disease behavior and location
Variable | Total | Patients with perianal disease | Patients without perianal disease | P value |
---|---|---|---|---|
N (%) | 499 | 144 (28.9%) | 355 (71.1%) | |
Age (years), mean (SD) | 32.3 (11.43) | 28.9 (10.05) | 33.7 (11.67) | < 0.0001 |
Male, n (%) | 348 (69.7%) | 102 (70.8%) | 246 (69.3%) | 0.7348 |
BMI (kg/m2), mean (SD) | 19.10 (3.198) | 19.29 (3.254) | 19.04 (3.182) | 0.5446 |
Age at disease onset (years), mean (SD) | 27.9 (10.63) | 25.3 (9.40) | 29.0 (10.92) | 0.0003 |
Age group at disease onset (years), n (%) | 0.0556 | |||
N | 499 | 144 | 355 | |
≤ 16 | 29 (5.8%) | 7 (4.9%) | 22 (6.2%) | |
17–39 | 401 (80.4%) | 125 (86.8%) | 276 (77.7%) | |
≥ 40 | 69 (13.8%) | 12 (8.3%) | 57 (16.1%) | |
Age at initial definite diagnosis (years), mean (SD) | 30.6 (11.01) | 27.7 (10.02) | 31.8 (11.19) | 0.0001 |
Time from disease onset to initial diagnosis (months), mean (SD) | 32.0 (46.43) | 29.0 (38.54) | 33.2 (49.27) | 0.3672 |
Time from initial diagnosis to enrollment (months), mean (SD) | 20.6 (39.06) | 14.8 (24.97) | 22.9 (43.29) | 0.0345 |
Time from disease onset to enrollment (months), mean (SD) | 52.6 (59.08) | 43.8 (44.55) | 56.2 (63.75) | 0.0341 |
Nicotine use history, n (%) | 0.0188 | |||
N | 442 | 124 | 318 | |
Never used | 382 (86.4%) | 116 (93.5%) | 266 (83.6%) | |
Current user | 36 (8.1%) | 6 (4.8%) | 30 (9.4%) | |
Former user | 24 (5.4%) | 2 (1.6%) | 22 (6.9%) | |
Alcohol use history, n (%) | 0.3203 | |||
N | 443 | 124 | 319 | |
Never used | 401 (90.5%) | 116 (93.5%) | 285 (89.3%) | |
Current user | 22 (5.0%) | 3 (2.4%) | 19 (6.0%) | |
Former user | 20 (4.5%) | 5 (4.0%) | 15 (4.7%) | |
Location, n (%) | < 0.0001 | |||
N | 493 | 143 | 350 | |
L1 | 137 (27.8%) | 23 (16.1%) | 114 (32.6%) | |
L2 | 71 (14.4%) | 14 (9.8%) | 57 (16.3%) | |
L3 | 277 (56.2%) | 105 (73.4%) | 172 (49.1%) | |
L4 | 8 (1.6%) | 1 (0.7%) | 7 (2.0%) | |
Behavior, n (%) | 0.0309 | |||
N | 495 | 144 | 351 | |
B1 | 247 (49.9%) | 84 (58.3%) | 163 (46.4%) | |
B2 | 148 (29.9%) | 32 (22.2%) | 116 (33.0%) | |
B3 | 100 (20.2%) | 28 (19.4%) | 72 (20.5%) | |
Crohn’s disease treatment information at baseline, n (%) | ||||
Immunomodulators | 207 (41.5%) | 64 (44.4%) | 143 (40.7%) | 0.4480 |
Anti-TNF agents | 164 (32.9%) | 60 (41.7%) | 104 (29.6%) | 0.0098 |
Aminosalicylates | 103 (20.6%) | 23 (16.0%) | 80 (22.8%) | 0.0896 |
Steroids | 99 (19.8%) | 24 (16.7%) | 75 (21.4%) | 0.2350 |
Enteral nutrition | 69 (13.8%) | 24 (16.7%) | 45 (12.8%) | 0.2618 |
Antibiotics | 65 (13.0%) | 30 (20.8%) | 35 (10.0%) | 0.0012 |
Anti-tuberculosis | 27 (5.4%) | 11 (7.6%) | 16 (4.6%) | 0.1705 |
Other agentsa | 115 (23.0%) | 40 (27.8%) | 75 (21.4%) | 0.1251 |
Variable | OR | 95% CI for OR | Parameter estimates (standard error) | Corresponding 95% CI | P value |
---|---|---|---|---|---|
Age (years) | 0.957 | 0.937, 0.977 | −0.044 (0.011)+ | −0.065, −0.023 | <.001* |
Sex (male vs. female) | 1.072 | 0.701, 1.638 | 0.069 (0.216) | −0.355, 0.493 | 0.749 |
BMI (18.5 - < 24 vs. < 18.5 kg/m2) | 1.082 | 0.632, 1.854 | 0.079 (0.275) | −0.459, 0.617 | 0.773 |
BMI (≥24 vs. < 18.5 kg/m2) | 1.795 | 0.688, 4.683 | 0.585 (0.489)+ | −0.373, 1.544 | 0.231 |
Nicotine use (former vs. Never) | 0.209 | 0.048, 0.904 | −1.564 (0.747)+ | −3.028, −0.100 | 0.036* |
Nicotine use (current vs. Never) | 0.460 | 0.187, 1.136 | −0.776 (0.461)+ | −1.679, 0.127 | 0.092 |
Alcohol use (former vs. Never) | 0.822 | 0.292, 2.313 | −0.196 (0.528) | −1.231, 0.839 | 0.710 |
Alcohol use (current vs. Never) | 0.389 | 0.113, 1.341 | −0.943 (0.631)+ | −2.180, 0.293 | 0.135 |
Time from disease onset to enrollment (months) | 0.996 | 0.992, 1.000 | −0.004 (0.002)+ | −0.008, − 0.000 | 0.036* |
Time from initial definite diagnosis to enrollment (months) | 0.993 | 0.986, 1.000 | −0.007 (0.003)+ | −0.014, − 0.000 | 0.039* |
Disease behavior (B2 vs. B1) | 0.514 | 0.320, 0.827 | −0.665 (0.243)+ | −1.141, − 0.190 | 0.006* |
Disease behavior (B3 vs. B1) | 0.755 | 0.453, 1.256 | −0.282 (0.260)+ | −0.791, 0.228 | 0.279 |
Disease behavior (B3 vs. B2) | 1.468 | 0.814, 2.646 | 0.384 (0.301)+ | −0.206, 0.973 | 0.202 |
Disease location (L3 vs. L1) | 3.052 | 1.834, 5.079 | 1.116 (0.260)+ | 0.607, 1.6252 | <.001* |
Disease location (L3 vs. L2) | 2.485 | 1.320, 4.681 | 0.911 (0.323)+ | 0.277, 1.544 | 0.005* |