Table 1 Demographic characteristics of the study cohorts
Characteristics | Before-matching cohort | Matched cohort | ||
|---|---|---|---|---|
TNF inhibitor cohort (n = 3286) | nbDMARD cohort (n = 19,565) | TNF inhibitor cohort (n = 2296) | nbDMARD cohort (n = 2296) | |
Female gender | 2298 (69.9) | 14,325 (73.2) | 1807 (78.7) | 1807 (78.7) |
Age groups | 50.4 ± 14.00 | 57.1 ± 14.26 | 50.3 ± 13.09 | 50.3 ± 13.09 |
 19 years | 10 (0.3) | 64 (0.3) | 6 (0.3) | 6 (0.3) |
 20–29 years | 270 (8.2) | 797 (4.1) | 158 (6.9) | 158 (6.9) |
 30–39 years | 516 (15.7) | 1587 (8.1) | 358 (15.6) | 358 (15.6) |
 40–49 years | 656 (20.0) | 3039 (15.5) | 477 (20.8) | 477 (20.8) |
 50–59 years | 918 (27.9) | 4890 (25.0) | 706 (30.7) | 706 (30.7) |
 60–69 years | 646 (19.7) | 5064 (25.9) | 443 (19.3) | 443 (19.3) |
 70–79 years | 241 (7.3) | 3448 (17.6) | 138 (6.0) | 138 (6.0) |
 80–89 years | 28 (0.9) | 668 (3.4) | 10 (0.4) | 10 (0.4) |
 90–99 years | 1 (0) | 8 (0) | 0 (0) | 0 (0) |
Comorbiditiesa | ||||
 Hypertension | 874 (26.6) | 7100 (36.3) | 474 (20.6) | 474 (20.6) |
 Diabetes | 324 (9.9) | 2662 (13.6) | 93 (4.1) | 93 (4.1) |
 Dyslipidemia | 521 (15.9) | 3448 (17.6) | 221 (9.6) | 221 (9.6) |
 CLD | 539 (16.4) | 2935 (15.0) | 208 (9.1) | 208 (9.1) |
 CVD | 364 (11.1) | 4083 (20.9) | 128 (5.6) | 128 (5.6) |
 COPD | 71 (2.2) | 808 (4.1) | 7 (0.3) | 7 (0.3) |
 PUD | 503 (15.3) | 1982 (10.1) | 0 (0) | 0 (0) |
Number of comorbiditiesa | ||||
 0 | 1649 (50.2) | 8491 (43.4) | 1493 (65.0) | 1493 (65.0) |
 1 | 959 (29.2) | 5043 (25.8) | 568 (24.7) | 568 (24.7) |
 2 or more | 678 (20.6) | 6031 (30.8) | 235 (10.2) | 235 (10.2) |
Charlson comorbidity scorea | ||||
 1 | 949 (28.9) | 5376 (27.5) | 775 (33.8) | 833 (36.3) |
 2 | 936 (28.5) | 4907 (25.1) | 715 (31.1) | 656 (28.6) |
 3 or more | 1401 (42.6) | 9282 (47.4) | 806 (35.1) | 807 (35.1) |
Disease duration (months)b | 33.8 ± 29.79 | 0 ± 0 | 35.6 ± 30.02 | 35.6 ± 30.15 |
TNF inhibitor treatmentc | ||||
 Adalimumab user | 1572 (47.8) | . | 1089 (47.4) | . |
 Etanercept user | 1270 (38.6) | . | 882 (38.4) | . |
 Golimumab user | 401 (12.2) | . | 285 (12.4) | . |
 Infliximab user | 673 (20.5) | . | 474 (20.6) | . |
 Number of TNF inhibitors | 1.2 ± 0.45 | . | 1.2 ± 0.44 | . |
 Duration of TNF inhibitors (months) | 37.6 ± 25.15 | . | 38.2 ± 25.23 | . |
 PDC of TNF inhibitorsd | 0.98 ± 0.043 | . | 0.98 ± 0.044 | . |
nbDMARD treatmentc | ||||
 Methotrexate user | 2983 (90.8) | 14,954 (76.4) | 2136 (93.0) | 1775 (77.3) |
 Hydroxychloroquine user | 2539 (77.3) | 16,343 (83.5) | 1843 (80.3) | 1937 (84.4) |
 Sulfasalazine user | 2355 (71.7) | 9664 (49.4) | 1624 (70.7) | 1180 (51.4) |
 Leflunomide user | 1752 (53.3) | 7061 (36.1) | 1278 (55.7) | 884 (38.5) |
 Number of nbDMARD | 3.6 ± 1.41 | 3.1 ± 1.35 | 3.7 ± 1.37 | 3.3 ± 1.40 |
 Duration of nbDMARD (months) | 37.9 ± 26.60 | 49.8 ± 35.46 | 39.8 ± 26.83 | 35.4 ± 26.71 |
 PDC of nbDMARDd | 0.85 ± 0.312 | 0.73 ± 0.303 | 0.88 ± 0.288 | 0.82 ± 0.328 |
Anti-inflammatory treatmentc | ||||
 PDC of oral corticosteroidsd | 0.73 ± 0.360 | 0.58 ± 0.355 | 0.75 ± 0.351 | 0.68 ± 0.383 |
 PDC of NSAIDsd | 0.85 ± 0.262 | 0.64 ± 0.340 | 0.86 ± 0.255 | 0.74 ± 0.348 |
Type of institution | ||||
 Tertiary hospital | 3019 (91.9) | 13,180 (67.4) | 2114 (92.1) | 1556 (67.8) |
 General hospital | 178 (5.4) | 2398 (12.3) | 119 (5.2) | 262 (11.4) |
 Community hospitals/clinics/others | 89 (2.7) | 3987 (20.4) | 63 (2.7) | 478 (20.8) |
Department | ||||
 Internal medicine | 3144 (95.7) | 11,629 (59.4) | 2193 (95.5) | 1394 (60.7) |
 Orthopedic surgery | 128 (3.9) | 6280 (32.1) | 93 (4.1) | 708 (30.8) |
 Other | 14 (0.4) | 1656 (8.5) | 10 (0.4) | 194 (8.4) |
Income | ||||
 High | 926 (28.2) | 5767 (29.5) | 639 (27.8) | 570 (24.8) |
 Intermediate | 1331 (40.5) | 7971 (40.7) | 942 (41.0) | 981 (42.7) |
 Low | 1029 (31.3) | 5827 (29.8) | 715 (31.1) | 745 (32.4) |
Follow-up duration (years) | 3.8 ± 2.3 | 6.0 ± 3.3 | 3.9 ± 2.3 | 3.7 ± 2.3 |