Table 2. Diagnostic accuracy of ALT/AST ratio alone at various ALT/AST ratio cut-points compared to the presence of hepatic steatosis on computed tomography scan in the Framingham Heart Study.

ALT/AST ratio cut-points	Prevalence steatosis (%)*	Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)
0.9	74	90	33	33	90
1.05	56	80	51	37	87
1.18	44	70	65	42	85
1.22	39	66	70	44	85
1.33	29	55	80	50	83
1.5	17	34	91	54	79

ALT, alanine aminotransferase; AST, aspartate aminotransferase; PPV, positive predictive value; NPV, negative predictive value

^*Prevalence of hepatic steatosis in the Framingham Heart Study sample based on ALT/AST ratio cut-point.