Slopes of average change in a given risky sexual behaviour over follow-up and rate ratio for every 4 or 12 (for STIs) weeks increase in follow-up
| STIs | Coefficient (slope) (95% CI) | Rate ratio | P value |
| Any STI | −0.15 (−0.19 to −0.11) | 0.86 (0.83–0.90) | <0.001 |
| Chlamydia trachomatis | −0.07 (−0.14 to 0.004) | 0.93 (0.87–1.01) | 0.066 |
| Trichomonas vaginalis | −0.22 (−0.27 to −0.16) | 0.81 (0.76–0.85) | <0.001 |
| Neisseria gonorrhoeae | −0.16 (−0.27 to −0.06) | 0.85 (0.77–0.94) | 0.002 |
| Sexual behaviour (self-reported) | |||
| Condom use at last sex act | −0.002 (−0.03 to 0.03) | 0.99 (0.97–1.03) | 0.896 |
| Having two or more sexual partners | −0.02 (−0.04 to 0.008) | 0.98 (0.97–1.001) | 0.06 |
| Non condom use over time | −0.03 (−0.07 to 0.01) | 0.97 (0.94–1.01) | 0.177 |