Table 1 Characteristics of study participants in Guangdong, China, 2019 (N = 1275)
From: Chlamydia infection, PID, and infertility: further evidence from a case–control study in China
Characteristics | Infertile women (n = 255) | Pregnant women (n = 510) | Non-pregnant women (n = 510) |
|---|---|---|---|
n (%) | n (%) | n (%) | |
Age (years, \({\overline{\text{x}}}\) ± s) | 29.8 ± 4.4 | 29.8 ± 4.4 | 30.0 ± 4.5 |
< 25 | 26 (10.2) | 52 (10.2) | 61 (12.0)* |
25–29 | 111 (43.5) | 222 (43.5) | 169 (33.1) |
≥ 30 | 118 (46.3) | 236 (46.3) | 280 (54.9) |
BMI (kg/m2, \({\overline{\text{x}}}\) ± s) | 21.1 ± 2.7 | 20.6 ± 2.5* | 20.9 ± 2.1 |
≤ 18.4 | 40 (15.7) | 97 (19.0) | 45 (8.8)* |
18.5–23.9 | 173 (67.8) | 356 (69.8) | 415 (81.4) |
≥ 24 | 42 (16.5) | 57 (11.2) | 50 (9.8) |
Marital status | |||
Single | 23 (9.0) | 29 (5.7) | 98 (19.2)* |
Married | 232 (91.0) | 475 (93.1) | 392 (76.9) |
Other or unknown | 0 (0.0) | 6 (1.2) | 20 (3.9) |
Education | |||
High school or lower | 153 (60.0) | 286 (56.1) | 321 (62.9) |
Bachelor or higher | 102 (40.0) | 220 (43.1) | 183 (35.9) |
Missing | 0 (0.0) | 4 (0.8) | 6 (1.2) |
Income (dollars/year)a | |||
< 1500 | 179 (70.2) | 440 (86.3)* | 485 (95.1)* |
1500–4499 | 46 (18.0) | 57 (11.2) | 11 (2.2) |
≥ 4500 | 30 (11.8) | 7 (1.4) | 8 (1.6) |
Missing | 0 (0.0) | 6 (1.2) | 6 (1.2) |
Smoking | |||
No | 249 (97.6) | 500 (98.0) | 492 (96.5) |
Yes | 6 (2.4) | 9 (1.8) | 15 (2.9) |
Missing | 0 (0.0) | 1 (0.2) | 3 (0.6) |
Alcohol | |||
No | 216 (84.7) | 444 (87.1) | 418 (82.0) |
Yes | 39 (15.3) | 56 (11.0) | 81 (15.9) |
Missing | 0 (0.0) | 10 (2.0) | 11 (2.2) |
Chronic conditionb | |||
No | 244 (95.7) | 449 (88.0)* | 479 (93.9) |
Yes | 11 (4.3) | 61 (12.0) | 31 (6.1) |
Age at sexual debut (years, \({\overline{\text{x}}}\) ± s) | 22.1 ± 3.7 | 22.5 ± 3.9 | 21.4 ± 3.7* |
< 25 | 197 (77.3) | 349 (68.4) | 393 (77.1) |
≥ 25 | 58 (22.7) | 141 (27.6) | 82 (16.1) |
Missing | 0 (0.0) | 20 (3.9) | 35 (6.9) |
Parity | |||
0 | 168 (65.9) | 159 (31.2)* | 114 (22.4)* |
≥ 1 | 87 (34.1) | 351 (68.8) | 394 (77.3) |
Missing | 0 (0.0) | 0 (0.0) | 2 (0.4) |
Other genital tract infectionc | |||
No | 179 (70.2) | 468 (91.8)* | 391 (76.7) |
Yes | 76 (29.8) | 42 (8.2) | 119 (23.3) |
NAAT chlamydia infectiond | |||
Neg | 240 (94.1) | 472 (92.5) | 471 (92.4) |
Pos | 15 (5.9) | 37 (7.3) | 36 (7.1) |
Missing | 0 (0.0) | 1 (0.2) | 3 (0.6) |
PIDe | |||
No | 211 (82.7) | 492 (96.5)* | 464 (91.0)* |
Yes | 44 (17.3) | 15 (2.9) | 46 (9.0) |
Missing | 0 (0.0) | 3 (0.6) | 0 (0.0) |
Chlamydia infection historyf | |||
No | 249 (97.6) | 506 (99.2)* | 508 (99.6)* |
Yes | 6 (2.4) | 2 (0.4) | 2 (0.4) |
Missing | 0 (0.0) | 2 (0.4) | 0 (0.0) |