HIV prevention for Latino adolescent mothers and their partners.

This study evaluates the outcomes of a theory-based, couple-focused HIV prevention program for Latino adolescent mothers and their male partners. The sample includes 49 couples (98 individuals) who receive either the intervention or only an HIV information session (comparison). The six-session, culturally appropriate intervention was developed through a community-academic partnership. Findings at the 6-month evaluation show that the probability of unprotected sex is significantly reduced and intentions to use condoms increase over time for participants in the experimental group, compared with the comparison group (p < .001), although AIDS knowledge improves for participants in both groups. Females in both groups have higher intentions of using condoms (p < .01) and lower probability of unsafe sex (p < .05) at baseline and over time, compared with their male partners. The intervention is well accepted by the inner-city adolescents and is realistic for implementation in a community setting.

Modeling treatment effects on binary outcomes with grouped-treatment variables and individual covariates.

During evaluation of treatment effects in observational studies, confounding is a constant threat because it is always possible that patients with a better prognosis, not adequately characterized by measured covariates, are chosen for a specific therapy. Ecologic analyses may avoid confounding that would be present in analysis at the individual level because variations in regional or hospital practice may be unrelated to prognosis. The authors used simulated data with an excluded confounder to evaluate the reliability and limitations of the grouped-treatment approach, a method of incorporating an ecologic measure of treatment assignment into an individual-level multivariable model, similar to the instrumental variable approach. Estimates based on the grouped-treatment approach were closer to the true value than those of standard individual-level multivariable analysis in every simulation. Furthermore, confidence intervals based on the grouped-treatment approach achieved approximately their nominal coverage, whereas those based on individual-level analyses did not. The grouped-treatment approach appears to be more reliable than standard individual-level analysis in situations where the grouped-treatment variable is unassociated with the outcome except via the actual treatment assignment and measured covariates.

Trihalomethane levels in home tap water and semen quality.

BACKGROUND: Trihalomethanes (THMs) are byproducts of drinking water chlorination whose effects on semen quality have not been previously studied in humans. METHODS: We examined the relationship of THMs to semen quality in 157 healthy men from couples without known risk factors for infertility. Total THM (TTHM) levels were assigned based on water utility measurements taken during the 90 days preceding semen collection. We analyzed continuous semen parameters in relation to total and individual THMs, adjusting for potential confounders by using repeated measures analyses. RESULTS: TTHM level was not associated with decrements in semen quality. Percent normal morphology decreased and percent head defects increased at higher levels of an ingestion metric (TTHM multiplied by cold home tap water consumption). At the highest level of the ingestion metric (>160 mug/L x glasses/day, which is equivalent to >2 glasses/day of water containing 80 mug/L) we observed a difference of -7.1 (95% confidence interval = -12.7 to -1.6) for percent morphologically normal sperm compared with the lowest level (