A vectorised function to calculate the APRI score, a predictor of hepatic fibrosis.
apri(ast, plt, ast_uln = 40)
numeric vector of APRI scores
Reference: Lin ZH, Xin YN, Dong QJ, et al. Performance of the aspartate aminotransferase-to-platelet ratio index for the staging of hepatitis C-related fibrosis: an updated meta-analysis. Hepatology 2011; 53:726-736.
apri(ast = 38, plt = 150, ast_uln = 40)
#> [1] 0.6333333
# if the lab upper limit of normal is 40, ast_uln can be omitted
apri(ast = 160, plt = 75)
#> [1] 5.333333