Table 4.
Generalized estimating equation modelsa predicting any unprotected sex, unprotected sex with main partners, and unprotected sex with casual partners (n = 245 participants assessed for a total of 21,449 person-days)
| Predictor | Any unprt. sex OR (95% CI) | Unprt. w/ main OR (95% CI) | Unprt. w/ casual OR (95% CI) |
| Years age | 0.99 | 0.98 | 1.03 |
| (0.97–1.01) | (0.95–1.00) | (0.96–1.11) | |
| Ethnicity, | 1.14 | 1.15 | 1.28 |
| white = 1 | (0.76–1.70) | (0.71–1.85) | (0.43–3.79) |
| Frequency of cocaine use, | 1.00 | 1.00 | 1.02* |
| last 90 days | (1.00–1.01) | (0.99–1.01) | (1.01–1.03) |
| Partner alcohol problem, | 1.18 | 1.64 | 0.55 |
| yes = 1 | (0.81–1.71) | (1.02–2.64) | (0.15–1.99) |
| Sex work, | 1.14 | 0.42* | 18.27† |
| yes = 1 | (0.72–1.80) | (0.21–0.85) | (3.23–103.32) |
| Any alcohol use, | 1.95† | 1.71† | 2.61† |
| yes = 1 | (1.61–2.36) | (1.41–2.06) | (1.51–4.52) |
Notes: Unprt. = unprotected; OR = odds ratio; CI = confidence interval.
The specified working correlation structure was autoregressive lag 1; coefficients give the population averaged estimated effects on the odds of having sex on the observed day; any alcohol use is a time-varying covariate assessed using Timeline Followback methodology; all other predictors are time-invariant covariates assessed at baseline; confidence interval estimates and tests of significance are based on the sandwich (robust) standard errors.
p < .05;
p < .01.