Calculate estimated Blood Alcohol Concentration (eBAC)

Compute the continuous estimated Blood Alcohol Concentration using the standard Widmark formula. Mirrors the Python morie.calculate_ebac().

Usage

morie_calculate_ebac(drinks, weight_lbs, hours, gender_constant)

Arguments

drinks

Number of standard drinks consumed (1 drink = 14 g alcohol).

weight_lbs

Body weight in pounds.

hours

Hours elapsed since drinking began.

gender_constant

Widmark gender multiplier (0.73 men, 0.66 women).

Value

Non-negative numeric scalar: estimated BAC.

Details

The Widmark formula in US units (Matthews and Miller 1979) is: $$eBAC = (A \times 5.14) / (weight\_lbs \times r) - 0.015 \times hours$$ where \(A\) is the alcohol in fluid ounces of ethanol (a 14 g standard drink is 0.6 fl oz, so \(A = 0.6 \times drinks\)) and \(r\) is the gender constant (0.73 for men, 0.66 for women). Counting each drink as one ounce overstated eBAC by a factor of 1/0.6. Returned values are clipped at zero.

Examples

morie_calculate_ebac(drinks = 4, weight_lbs = 180, hours = 2, gender_constant = 0.73)
#> [1] 0.06388128