Validation of measures of condom and other contraceptive use among women at high risk for HIV infection and unintended pregnancy.

This study assessed the applicability of the transtheoretical model of behavior change (J.O. Prochaska & C.C. DiClemente, 1983, 1984) to the measurement of contraceptive use among 296 women at high risk for HIV infection and transmission. Structural equation modeling suggested that a measure of general contraceptive use could be used to assess use of oral contraceptives and hormonal implants but that measurement of condom use required separate assessments for main and other partners. Self-efficacy (SE) and decisional balance scales were internally consistent for general contraceptive use, for condom use with main partners, and for condom use with other partners. Consistent with research on other health behaviors, SE scores rose significantly across stages, from precontemplation to maintenance, and a shift in decisional balance was observed for 2 of 3 behaviors. This measurement strategy may enhance the ability to evaluate prevention programs for women at risk.