Table 1.
Outcome measures, sub-components, and their definitions in the Combination Prevention Effectiveness (COPE) study for young men who have sex with men and transgender women who exchange sex, Thailand (2018–2020).
| Outcome measure and sub-components | Operational definition |
|---|---|
| HIV incidence | HIV infections not on PrEP per 100 PY not on PrEP among all study participants; HIV infections on PrEP per 100 PY on PrEP among all study participants |
| HIV infection | Positive HIV Ab and positive NAAT |
| PrEP status at HIV infection | PrEP status at midpoint between last negative and first positive HIV tests |
| Time on PrEP | Days between starting PrEP and stopping PrEP or study exit |
| Time not on PrEP | Days between study entry and starting PrEP or study exit; days between stopping PrEP and starting PrEP or study exit |
| PrEP initiation | Date first received study PrEP after enrollment or after having stopped PrEP use for more than 14 days |
| Stopping PrEP | Date study PrEP would have run out with daily use and did not receive additional study PrEP within 14 days |
| Same-day PrEP initiation | Received study PrEP on day of study enrollment |
| PrEP persistence | Among participants initiating PrEP within 30 days of enrollment, on PrEP at the 12-month assessment regardless of any time off PrEP in the interim |
| Adherence | Self-report of taking 4 or more PrEP doses in the last 7 days if not using exogenous feminizing hormones; self-report of taking 7 doses in the last 7 days if using exogenous feminizing hormones |
| Exogenous feminizing hormone use | Self-report of using exogenous feminizing hormones since the prior study visit |
| [Chlamydia/gonorrhea/syphilis] incidence | [Chlamydia/gonorrhea/syphilis] infections per 100 PY not on PrEP among all study participants; [chlamydia/gonorrhea/syphilis] infections per 100 PY on PrEP among all study participants |
| Rectal chlamydia infection | Positive NAAT result from rectal swab |
| Rectal gonorrhea infection | Positive NAAT result from rectal swab |
| Syphilis infection | Treponema pallidum detection by rapid plasma reagin (RPR) ≥ 1:8 and T. pallidum antibody positive |
| PrEP status at [chlamydia/gonorrhea/syphilis] infection | PrEP status at midpoint between positive [chlamydia/gonorrhea/syphilis] test and prior [chlamydia/gonorrhea/syphilis] test |
PrEP, pre-exposure prophylaxis for HIV; PY, person-years; Ab, antibody test; NAAT, nucleic acid amplification test.