Estimated blood alcohol concentrations for child and adolescent drinking and their implications for screening instruments.

Objective: Blood alcohol concentrations (BACs) in children after consumption of different numbers of standard drinks of alcohol have not been estimated previously. The goal was to determine the number of drinks at each age that led to a BAC of > or =80 mg/dL, the National Institute on Alcohol Abuse and Alcoholism criterion for binge drinking.

Methods: The updated Widmark equation to estimate BAC was modified to take account of the differing body composition (total body water) and accelerated rates of ethanol elimination of children. The modified formula was used with 1999-2002 National Health and Nutrition Examination Survey data to estimate BACs for >4700 children and adolescents from 9 through 17 years of age, for intake levels of 1 to 5 standard drinks.

Results: The estimated BACs for children after consumption of just 3 standard drinks within a 2-hour period were between 80 and 139 mg/dL for boys 9 to 13 years of age and for girls 9 to 17 years of age, indicating substantial potential alcohol impairment. With 5 drinks within 2 hours (the level used to define binge drinking among college students), children 9 to 13 years of age were estimated to have BACs 2 to 3 times the adult legal limit for intoxication of 80 mg/dL.

Conclusion: Binge drinking should be defined as > or =3 drinks for 9- to 13-year-old children, as > or =4 drinks for boys and > or =3 drinks for girls 14 or 15 years of age, and as > or =5 drinks for boys and > or =3 drinks for girls 16 or 17 years of age.