Trends in estimated prevalence of chlamydial infections by gender and race: Baltimore, 1997–98 and 2006–09.

Notes: Results for adults ages 18 to 35 from the Baltimore STD and Behavior Survey (BSBS) and the Monitoring STIs Survey Program (MSSP). Table shows unweighted base Ns for percentages and weighted estimates of the percentage of the population that was infected. 95% confidence intervals were calculated using statistical algorithms that take account of the complex sample designs of the surveys. ORs contrast the estimated prevalence in 2006–09 to the estimated prevalence in 1997–98. All adjusted ORs (AOR) were calculated in logit regressions that included the following control variables: age in years, education (4 categories: less than high school; high school graduate; some college; college graduate or higher); marital status (3 categories: married; cohabiting but not married; and single, separated, divorced, or widowed). AOR for comparisons within race categories included an additional control for gender (male vs. female). AOR for comparisons within gender categories included an additional control for race (black vs. non-black). AOR for comparison of the total population included controls for both gender and race.(a) ORs cannot be calculated because no infections were found among nonblack females in 1997–98.(b) AOR not shown. Category 4 of education (college graduate or higher) predicts non-infection perfectly. If observations with level 4 of education were excluded, AOR would be 0.69 (95% CI: 0.1, 3.7); p>0.5.(c) AOR not shown. Categories 3 and 4 of education (some college, and college graduate or higher) predict non-infection perfectly. If observations with levels 3 and 4 of education were excluded, AOR would be 0.41 (95% CI: 0.04, 4.13); p = 0.45.