Table 1.
Univariate associations of potential predictors with HIV infection risk
| Predictors | HIV Prevalence % (N) | Odd ratio (95% confidence interval) | P value |
|---|---|---|---|
| HIV prevalence | 12.7 (455/3588) | ||
| Age at interview (year): | |||
| Mean ± SD1 | 29.8±7.8 | 0.99 (0.98, 1.01)2 | 0.20 |
| ≤30 | 13.0 (301/2,312) | Ref. | |
| >30 | 12.1 (154/1,276) | 0.92 (0.75, 1.13) | 0.41 |
| Ethnicity | |||
| Han | 12.5 (421/3,361) | Ref. | |
| Others | 15.0 (34/227) | 1.23 (0.84, 1.80) | 0.28 |
| Currently married with a woman | |||
| No | 13.2 (402/3,049) | Ref. | |
| Yes | 9.8 (53/539) | 0.72 (0.53, 0.97) | 0.03 |
| Years of education | |||
| ≤12 | 12.4 (125/1,009) | Ref. | |
| >12 | 12.8 (330/2,579) | 1.04 (0.83, 1.29) | 0.74 |
| Full-time employed | |||
| No | 12.9 (90/695) | Ref. | |
| Yes | 12.6 (365/2,893) | 0.97 (0.76, 1.24) | 0.81 |
| Beijing permanent residents (Hukou) | |||
| No | 14.4 (389/2,699) | Ref. | |
| Yes | 7.4 (66/889) | 0.48 (0.36, 0.63) | <0.01 |
| Years of living in Beijing | |||
| Median (IQR1) | 5 (2–10) | 0.96 (0.93, 0.99)2 | <0.01 |
| ≤5 | 15.0 (278/1,851) | Ref. | |
| >5 | 10.2 (177/1,737) | 0.74 (0.58, 0.93) | 0.01 |
| Nitrite inhalants use in the past 3 months | |||
| No | 11.7 (307/2,627) | Ref. | |
| Yes | 15.4 (148/961) | 1.38 (1.11, 1.70) | <0.01 |
| Illegal drug use in the past 3 months | |||
| No | 12.1 (428/3,529) | Ref. | |
| Yes | 45.8 (27/59) | 6.11 (3.63, 10.30) | <0.01 |
| Alcohol use in the past 3 months | |||
| Never | 12.9 (203/1,574) | Ref. | |
| ≤1 time/month | 10.9 (121/1,108) | 0.83 (0.65, 1.05) | 0.12 |
| 2–4 times/month | 14.6 (87/594) | 1.16 (0.88, 1.52) | 0.29 |
| ≥5 times/month | 14.1 (44/312) | 1.11 (0.78, 1.58) | 0.56 |
| Alcohol consumption before sex in the past 3 months | |||
| Never | 11.8 (337/2,850) | Ref. | |
| Occasionally | 14.8 (78/527) | 1.30 (0.99, 1.69) | 0.06 |
| Sometimes | 16.9 (25/148) | 1.52 (0.97, 2.37) | 0.07 |
| Often | 23.8 (15/63) | 2.33 (1.29, 4.21) | 0.01 |
| Time since the first sex | |||
| Median (IQR1) | 7 (4–12) | 0.997 (0.98, 1.01) | 0.68 |
| <8 years | 12.3 (225/1,833) | Ref. | |
| ≥8 years | 13.1 (230/1,755) | 0.93 (0.76, 1.23) | 0.46 |
| Time since the first anal sex | |||
| Median (IQR1) | 6 (3–10) | 0.996 (0.98, 1.01) | 0.64 |
| <6 years | 12.6 (208/1,648) | Ref. | |
| ≥6 years | 12.7 (247/1,940) | 1.01 (0.83, 1.23) | 0.92 |
| Number of lifetime male sexual partner | |||
| Median (IQR1) | 9 (4–20) | 1.00 (0.999, 1.001) | 0.84 |
| <10 | 10.9 (198/1,815) | Ref. | |
| ≥10 | 14.5 (257/1,773) | 1.38 (1.14, 1.69) | <0.01 |
| Number of male sexual partners in the past 3 months | |||
| Median (IQR1) | 1 (1–2) | 1.00 (0.98, 1.02) | 0.73 |
| ≤1 | 11.8 (221/1,879) | Ref. | |
| >1 | 13.7 (234/1,709) | 1.19 (0.98, 1.45) | 0.08 |
| Unprotected receptive anal sex with male sexual partners in the past 3 months | |||
| No | 9.8 (268/2,743) | Ref. | |
| Yes | 22.1 (187/845) | 2.63 (2.14, 3.22) | <0.01 |
| Unprotected insertive anal sex with male sexual partners in the past 3 months | |||
| No | 12.3 (334/2,706) | Ref. | |
| Yes | 13.7 (121/882) | 1.13 (0.90, 1.41) | 0.29 |
| Sex with female partners in the past 3 months | |||
| No | 14.6 (150/1,025) | Ref. | |
| Yes | 11.9 (305/2,563) | 0.79 (0.64, 0.97) | 0.03 |
| Unprotected sex with female sexual partners in the past 3 months | |||
| No | 13.1 (438/3,346) | Ref. | |
| Yes | 4.0 (17/422) | 0.50 (0.30, 0.83) | 0.01 |
| Syphilis infection | |||
| No | 11.4 (378/3,319) | Ref. | |
| Yes | 28.6 (77/269) | 3.12 (2.35, 4.15) | <0.01 |
1
SD, standard deviation; IQR, interquartile range
2
Odds ratio per 1-unit increase