“True” association among women with high risk sexual behaviours
| HIV infected | HIV uninfected | Total | |
|---|---|---|---|
| Stratum specific relative risk (RR) for women with high risk sexual behaviours = (96/996)/(24/249) = 1.0. | |||
| Use of hormonal contraceptives | 96 | 900 | 996 |
| No use of hormonal contraceptives | 24 | 225 | 249 |