Table 1. Selected characteristics and smoking habits of study participants.
| General characteristics | Normal | CIN 1 | CIN 2/3 | Cervical cancer | Pa |
| (n = 592) | (n = 420) | (n = 165) | (n = 145) | ||
| Age, mean (SD) | 45.1 (10.3) | 39.9 (11.1) | 40.5 (10.4) | 51.2 (11.6) | <0.01 |
| ≤29, no (%) | 36 (6) | 87 (20) | 29 (18) | 3 (2) | |
| 30–39 | 148 (25) | 132 (32) | 53 (32) | 20 (14) | |
| 40–49 | 195 (33) | 118 (28) | 53 (32) | 50 (34) | |
| 50–59 | 160 (27) | 65 (16) | 21 (13) | 35 (24) | |
| ≥60 | 53 (9) | 18 (4) | 9 (5) | 37 (26) | <0.01 |
| Cigarette smoking, no (%) | |||||
| Non-smoker | 529 (89) | 345 (82) | 136 (82) | 129 (89) | |
| Ex-smoker | 22 (4) | 32 (8) | 10 (6) | 8 (6) | |
| Current smoker | 41 (7) | 43 (10) | 19 (12) | 8 (6) | 0.016 |
| Pack-years, no (%) | |||||
| Non-smoker | 529 (89) | 345 (83) | 136 (83) | 129 (89) | |
| <10 | 50 (8) | 63 (15) | 22 (13) | 10 (7) | |
| ≥10 | 13 (2) | 12 (3) | 7 (4) | 6 (4) | 0.013 |
| Passive smoking, no (%) | |||||
| No | 366 (62) | 223 (53) | 84 (51) | 84 (58) | |
| Yes | 226 (38) | 197 (47) | 81 (49) | 61 (42) | 0.013 |
| Exposure time of passive smoking, no (%) | |||||
| No | 366 (81) | 223 (62) | 83 (80) | 84 (74) | |
| <2 hours/day | 52 (12) | 89 (25) | 9 (9) | 20 (18) | |
| ≥2 hours/day | 33 (7) | 49 (14) | 12 (12) | 9 (8) | <0.01 |
| Ever use oral contraceptive, no (%) | |||||
| Never | 510 (86) | 349 (83) | 129 (78) | 119 (83) | |
| Current/Former | 82 (14) | 71 (17) | 36 (22) | 26 (17) | 0.090 |
| Menopausal status, no (%) | |||||
| Premenopausal | 371 (63) | 334 (80) | 135 (82) | 64 (44) | |
| Postmenopausal | 221 (37) | 86 (20) | 30 (18) | 81 (56) | <0.01 |
| Number of childbirth, no (%) | |||||
| 0 | 84 (14) | 121 (29) | 38 (23) | 6 (4) | |
| 1 | 79 (13) | 66 (16) | 18 (11) | 11 (8) | |
| 2 | 306 (52) | 170 (41) | 78 (47) | 72 (50) | |
| ≥3 | 123 (21) | 63 (15) | 31 (19) | 56 (39) | <0.01 |
| HPV infection status, no (%)b | |||||
| Negative | 219 (56) | 90 (24) | 37 (34) | 0 (0) | |
| Positive | 170 (44) | 280 (76) | 73 (66) | 54 (100) | <0.01 |
CIN, low-grade cervical intraepithelial neoplasia; SD, standard deviation.
aANOVA for continuous variable and χ2 for categorical variable.
bHPV infection status was determined by detection for 13 oncogenic HPV DNA types using hybrid capture 2.