“Observed” unadjusted association among all women*
| HIV infected | HIV uninfected | Total | |
|---|---|---|---|
| Unadjusted relative risk (RR) = (114/1905)/(66/2370) = 2.14 (95% CI: 1.60 to 2.89). | |||
| *Note that this example presumes that the exposure and outcome are measured perfectly, and the only errors are in the measurement of sexual behaviour; thus, the “true” and “observed” unadjusted tables (3 and 6, respectively), and the resulting unadjusted associations, are identical. | |||
| Use of hormonal contraceptives | 114 | 1791 | 1905 |
| No use of hormonal contraceptives | 66 | 2304 | 2370 |