TABLE 3 Independent Predictors of Knowledge of Sexual Contact as a Risk Factor for Infection with Hepatitis B. Middle and High School Students, Worcester, Massachusetts, 1993  Variable Odds Ratio 95% Confidence Interval P Vietnamese .23 .14, .38 <.001 African-American .81 .57, 1.13 .209 Hispanic .72 .55, .95 .018 White 1.0 Age 16 years or older 1.33 1.04, 1.72 .025 Taught about hepatitis B in school 4.02 3.27, 4.94 <.001 Knew definition of hepatitis B 2.34 1.88, 2.91 <.001 Academic performance* .88 .83, .95 <.001 Family member had hepatitis B 1.95 1.15, 3.31 .013 High school student 2.61 2.00, 3.40 <.001 Poor speaking English .35 .29, .50 .002 * Scaled as 7 levels, from "one of the best", to "near the bottom" compared to other students in respondent's class. O.R. indicates risk associated with change in one level.