Socio-demographic variables for this study included sex, race/ethnicity, age, marital status, educational attainment, and survey year. Age (12–17; 18–25; 26–49; 50+) and race/ethnicity (White; Black; Hispanic; Other), and total family income ($0–19,000; $20,000–49,000; $50,000–74,999; $75,000+) were treated as categorical variables. Educational attainment (less than high school; high school graduate or greater) was dichotomized.
