Table 4. Electronic health record validation of NAFLD phenotype.

Liver Biopsy and Clinical Notes as Gold Standard (n = 178)
	NAFLD Phenotype	NAFLD Phenotype
	ABALT*	ALT-threshold**
	(n = 241)	(n = 178)
PPV	0.89	0.89
Abdominal Imaging Studies and Clinical Notes as Gold Standard (n = 216)
	NAFLD Phenotype	NAFLD Phenotype
	ABALT*	ALT-threshold**
	(n = 216)	(n = 142)
PPV	0.71	0.84

* ALT > 30 for men and > 20 for women during at least two time points at least 6 months apart within a two-year period and no other chronic liver disease.

** ALT > 40 for men and > 30 for women during at least two time points at least 6 months apart within a two-year period and no other chronic liver disease irrespective of metabolic risk factors. Sample size is lower due to exclusion of n = 137 from cases/control due to intermediate ALT values between 20–30 units/L.

Abbreviations: ALT:alanine aminotransferase, M:male, F:female; NAFLD = non-alcoholic fatty liver disease, PPV = positive predictive value in the validation sample.