Table 1 Distribution of participants before and after propensity-score matching
Variables | OT group | Non–OT group | |
|---|---|---|---|
Before and after matching (n = 218) | Before matching (n = 7902) | After matching (n = 654) | |
n (%) | n (%) | n (%) | |
Sex | |||
 Male | 50 (22.9) | 3569 (45.2) | 165 (25.2) |
 Female | 168 (77.1) | 4333 (54.8) | 489 (74.8) |
Age (years) | |||
 19–24 | 109 (50.0) | 530 ( 6.7) | 313 (47.9) |
 25–29 | 51 (23.4) | 385 ( 4.9) | 174 (26.6) |
 30–34 | 27 (12.4) | 432 ( 5.5) | 80 (12.2) |
 35–39 | 9 ( 4.1) | 643 ( 8.1) | 24 ( 3.7) |
 40–44 | 10 ( 4.6) | 815 (10.3) | 29 ( 4.4) |
 45–49 | 7 ( 3.2) | 825 (10.4) | 22 ( 3.4) |
 50–54 | 4 ( 1.8) | 791 (10.0) | 9 ( 1.4) |
 55–59 | 0 ( 0.0) | 797 (10.1) | 0 ( 0.0) |
 60–64 | 0 ( 0.0) | 691 ( 8.7) | 0 ( 0.0) |
 ≥65 | 1 ( 0.5) | 1993 (25.2) | 3 ( 0.5) |
Follow-up period (years) | |||
 2 | 37 (17.0) | 873 (11.0) | 93 (14.2) |
 3 | 38 (17.4) | 1420 (18.0) | 137 (20.9) |
 4 | 34 (15.6) | 744 ( 9.4) | 97 (14.8) |
 5 | 30 (13.8) | 758 ( 9.6) | 84 (12.8) |
 6 | 29 (13.3) | 1025 (13.0) | 81 (12.4) |
 7 | 32 (14.7) | 1320 (16.7) | 107 (16.4) |
 8 | 18 ( 8.3) | 1762 (22.3) | 55 ( 8.4) |
Education level | |||
 ≤ Elementary school | 1 ( 0.5) | 1662 (21.0) | 3 ( 0.5) |
 Middle and high school | 41 (18.8) | 3476 (44.0) | 128 (19.6) |
 ≥ College | 176 (80.7) | 2764 (35.0) | 523 (80.0) |
Health insurance | |||
 Work | 158 (72.5) | 5382 (68.1) | 474 (72.5) |
 Region | 58 (26.6) | 2153 (27.2) | 173 (26.5) |
 Medical aid | 1 ( 0.5) | 292 ( 3.7) | 5 ( 0.8) |
 Others | 1 ( 0.5) | 75 ( 0.9) | 2 ( 0.3) |
Employment | |||
 No/do not know | 127 (58.3) | 3256 (41.2) | 378 (57.8) |
 Yes | 91 (41.7) | 4646 (58.8) | 276 (42.2) |
Equivalent income level | |||
 Q1 (lowest) | 11 ( 5.0) | 1613 (20.4) | 38 ( 5.8) |
 Q2 | 34 (15.6) | 1590 (20.1) | 97 (14.8) |
 Q3 | 36 (16.5) | 1588 (20.1) | 115 (17.6) |
 Q4 | 69 (31.7) | 1555 (19.7) | 205 (31.3) |
 Q5 (highest) | 68 (31.2) | 1556 (19.7) | 199 (30.4) |
Marital status | |||
 No | 171 (78.4) | 2154 (27.3) | 512 (78.3) |
 Yes | 47 (21.6) | 5748 (72.7) | 142 (21.7) |
Private insurance | |||
 No | 50 (22.9) | 2380 (30.1) | 146 (22.3) |
 Yes | 168 (77.1) | 5522 (69.9) | 508 (77.7) |