Unadjusted associations of selected participant characteristics with prevalent and incident concurrencies among 536 participants enrolled in the Project on Partner Dynamics, Los Angeles, California, USA, 2006–2009
| Characteristic | Prevalent concurrency | Incident concurrency | ||||
|---|---|---|---|---|---|---|
| Prevalence (%)† | PR | 95% CI | Incidence (%)† | RR | 95% CI | |
| Birth sex | ||||||
| Female | 17.1 | Ref | 9.5 | Ref | ||
| Male | 35.2 | 2.1 | 1.6 to 2.7** | 16.5 | 1.7 | 1.2 to 2.6** |
| Age (years) | ||||||
| 18–24 | 27.0 | Ref | 14.2 | Ref | ||
| 25–30 | 23.2 | 0.9 | 0.7 to 1.1 | 9.2 | 0.6 | 0.4 to 1.0 |
| Race/ethnicity | ||||||
| White, non-Hispanic | 24.6 | Ref | 12.7 | Ref | ||
| Black, non-Hispanic | 25.2 | 1.0 | 0.7 to 1.5 | 11.1 | 0.9 | 0.5 to 1.5 |
| Hispanic/Latino | 28.1 | 1.1 | 0.8 to 1.6 | 15.7 | 1.2 | 0.8 to 2.0 |
| Other | 23.4 | 1.0 | 0.6 to 1.5 | 7.0 | 0.6 | 0.3 to 1.2 |
| Age at sexual debut (years) | ||||||
| ≤15 | 31.3 | 1.4 | 1.1 to 1.8** | 15.6 | 1.5 | 1.0 to 2.2 |
| >15 | 22.4 | Ref | 10.7 | Ref | ||
| Number of sex partners, lifetime | ||||||
| 1–5 | 15.2 | Ref | 8.0 | Ref | ||
| 6–10 | 20.1 | 1.3 | 0.9 to 2.0 | 12.6 | 1.6 | 0.9 to 2.7 |
| >10 | 36.0 | 2.4 | 1.6 to3.4** | 14.8 | 1.9 | 1.1 to 3.0* |
| Alcohol or other drug use with 1+partners, 0–4 months ago | ||||||
| Yes | 31.4 | 2.0 | 1.5 to 2.6** | 16.3 | 2.3 | 1.4 to 3.6** |
| No | 15.9 | Ref | 7.2 | Ref | ||
| Alcohol or other drug use with 1+partners, 4–8 months ago | ||||||
| Yes | 27.9 | 1.5 | 1.1 to 2.0** | 12.4 | 1.2 | 0.8 to 1.9 |
| No | 18.9 | Ref | 10.5 | Ref | ||
| Perceived partner non-monogamy, 0–4 months ago | ||||||
| Yes | 48.8 | 2.7 | 2.1 to 3.4** | 33.2 | 4.6 | 3.0 to 7.0** |
| No | 18.1 | Ref | 7.2 | Ref | ||
| Perceived partner non-monogamy, 4–8 months ago | ||||||
| Yes | 36.8 | 1.9 | 1.5 to 2.4** | 15.3 | 1.4 | 0.9 to 2.3 |
| No | 19.5 | Ref | 10.8 | Ref | ||
*p<0.05.
**p<0.01.
†Concurrency was defined as having overlapping partnerships during the 4-month recall period. Incident concurrency was defined as concurrency among participants who were not concurrent during the preceding recall period (ie, 4–8 months ago).
PR, prevalence ratio; RR, risk ratio.