Variable | N (% of population)† | Median (IQR) AFS | Crude HR (95% CI) | p Value* | Adjusted HR (95% CI)‡ | p Value** |
Geographical location | 0.008 | 0.04 | ||||
Rural | 2886 (72) | 19.4 (17.2–N/A) | 1.0 | 1.0 | ||
Urban | 97 (2) | 20.1 (16.9–N/A) | 0.96 (0.64 to 1.43) | 0.85 (0.57 to 1.26) | ||
Periurban | 1046 (26) | 18.6 (16.6–22.9) | 1.22 (1.07 to 1.38) | 1.16 (1.03 to 1.32) | ||
Education (grade-for-age) | <0.001 | <0.001 | ||||
Age appropriate | 2287 (22) | 18.5 (16.6–N/A) | 1.0 | 1.0 | ||
Behind by 1 year | 2249 (21) | 19.6 (17.1–N/A) | 0.72 (0.59 to 0.87) | 0.73 (0.60 to 0.87) | ||
Behind 2+ years | 5226 (49) | 19.4 (17.2–N/A) | 0.71 (0.61 to 0.84) | 0.71 (0.61 to 0.84) | ||
Complete secondary | 773 (7) | 18.5 (16.9–22.1) | 0.88 (0.67 to 1.16) | |||
School attendance | <0.001 | <0.001 | ||||
Attending school | 8564 (80) | 19.5 (17.0–N/A) | 1.0 | 1.0 | ||
Not in school | 599 (6) | 18.5 (16.8–21.0) | 1.55 (1.27 to 1.90) | 1.44 (1.17 to 1.77) | ||
Complete secondary | 773 (7) | 18.5 (16.9–22.1) | 1.22 (0.98 to 1.51) | 0.90 (0.71 to 1.15) | ||
Mother member of household | 0.003 | 0.003 | ||||
No | 3982 (38) | 18.9 (16.8–22.1) | 1.0 | 1.0 | ||
Yes | 6616 (62) | 19.6 (17.2–N/A) | 0.84 (0.75 to 0.94) | 0.83 (0.74 to 0.94) | ||
Father member of household | 0.01 | |||||
No | 6211 (59) | 19.0 (17.0–22.6) | 1.0 | |||
Yes | 4387 (41) | 19.8 (17.2–N/A) | 0.86 (0.76 to 0.97) | |||
Mother dead | 0.03 | |||||
No | 8607 (81) | 19.3 (17.1–N/A) | 1.0 | |||
Yes | 1594 (15) | 18.7 (16.6–22.1) | 1.19 (1.02 to 1.38) | |||
Father dead | 0.001 | 0.002 | ||||
No | 7282 (69) | 19.5 (17.1–N/A) | 1.0 | 1.0 | ||
Yes | 2816 (27) | 18.7 (16.8–21.9) | 1.23 (1.09 to 1.39) | 1.21 (1.07 to 1.37) | ||
Ever taken alcohol | <0.001 | <0.001 | ||||
No | 1286 (32) | 19.8 (17.4–N/A) | 1.0 | 1.0 | ||
Yes | 330 (8) | 16.3 (14.5–18.6) | 1.89 (1.55 to 2.30) | 1.60 (1.30 to 1.98) | ||
Missed 2003 survey | 2413 (60) | 19.2 (17.1–N/A) | 1.02 (0.89 to 1.17) | 1.46 (1.15 to 1.86) | ||
Ever smoked | <0.001 | <0.001 | ||||
No | 1551 (38) | 19.3 (16.9–N/A) | 1.0 | 1.0 | ||
Yes | 84 (2) | 16.9 (16.3–18.3) | 2.70 (1.99 to 3.66) | 1.99 (1.45 to 2.73) | ||
Community in danger | 0.02 | |||||
No/don’t know | 748 (19) | 19.3 (16.8–N/A) | 1.0 | |||
Yes | 846 (21) | 18.9 (16.8–22.8) | 1.23 (1.03 to 1.48) | |||
Know people who have/had AIDS§ | <0.001 | <0.001 | ||||
No | 1341 (33) | 19.4 (17.0–N/A) | 1.0 | 1.0 | ||
Yes (1+) | 274 (7) | 17.8 (16.4–20.4) | 1.74 (1.41 to 2.14) | 1.67 (1.36 to 2.06) | ||
HIV is transmitted by utensils¶ | 0.01 | |||||
No | 1027 (25) | 18.8 (16.6–22.6) | 1.0 | |||
Yes/don’t know | 588 (15) | 20.3 (17.8–N/A) | 0.77 (0.61 to 0.97) | |||
A healthy-looking person can have HIV | <0.001 | <0.001 | ||||
No | 374 (9) | 20.6 (17.7–N/A) | 1.0 | 1.0 | ||
Yes | 1242 (31) | 18.6 (16.5–21.9) | 1.63 (1.29 to 2.06) | 1.48 (1.16 to 1.87) |
HR, hazard ratio; N/A, not applicable.
*Univariate likelihood ratio test p value.
†Totals vary because of missing values. The percentage distribution is based on the population of 4029 virgins. For time-varying characteristics it is based on person-years and one individual could contribute to different categories during the study period.
‡N = 4029. Missing indicators were used to represent the individuals with no information in multivariable models, adjusted for all other factors in the column, factors with a likelihood ratio test p value ⩽0.05.
§Knowing people with HIV was highly correlated with knowing relatives and neighbours with HIV and only the variable “knowing people with HIV” was considered for the multivariable analysis.
¶Similar non-significant results were attained for the questions about other modes of HIV transmission.
**Likelihood ratio test p value for the contribution of the variable to the multivariable model.
Note: Hazard ratios >1 indicate that the AFS is younger than the AFS for the reference category.