A rose by any other name? Objective knowledge, perceived knowledge, and adolescent male condom use.

OBJECTIVE: To investigate the role of objective and perceived knowledge about condoms in adolescent males' condom use at first intercourse.
METHODS: A longitudinal analysis was conducted of data from a nationally representative sample of 404 virgin male adolescents who were aged 15 to 17 years at wave 1 and reported becoming sexually experienced at the second wave of data collection. Objective knowledge was measured as a 5-item knowledge test about condoms. Perceived knowledge was measured as a 5-item scale regarding participants' confidence about their answers on the objective knowledge test. Condom use was assessed by self-report.
RESULTS: Objective and perceived knowledge were moderately correlated with each other. Male adolescents with low objective but high perceived knowledge were identified as being at particular risk for not using a condom in that they were nearly 3 times less likely to report using a condom at first intercourse (odds ratio: 0.35) than those with other levels of objective and perceived knowledge.
CONCLUSIONS: Previous evidence suggests that knowledge about sex does not accurately predict sexual behavior. This lack of predictive accuracy may be because studies have focused only on objective knowledge. Our results suggest that both objective and perceived knowledge serve as antecedents to male condom use at first intercourse. However, those with higher perceived knowledge, particularly in the context of low objective knowledge, may be at greater risk for not using condoms. Addressing not only objective but also perceived knowledge may increase the effectiveness of interventions that are designed to increase rates of condom use among male adolescents.