Table 1.

Modeling variables used in various clinical models

Characteristic	Reduceda ATN Model	LASSO Model		Stepwise Model		Parsimonious Model
		Mortality	Recovery	Mortality	Recovery	Mortality	Recovery
Age	Age	Age	Age	Age	Age	Age	Age
Chronic hypoxemia	Mechanical ventilation	Mechanical ventilation	Mechanical ventilation	Mechanical ventilation	Mechanical ventilation	Mean arterial pressure	Mean arterial pressure
Cardiovascular disease	Arterial pH (Z-score)	Arterial pH (Z-score)	Arterial pH (Z-score)	Arterial pH (Z-score)	Arterial pH (Z-score)	Mechanical ventilation	Mechanical ventilation
Malignancy	Total bilirubin	Total bilirubin	Total bilirubin	Total bilirubin	Total bilirubin	Total bilirubin	Total bilirubin
Immunosuppressive therapy	Mean arterial pressure	Mean arterial pressure	Mean arterial pressure	Platelets	Platelets
Ischemic AKI	Platelets	Platelets	Platelets	Mean arterial pressure	Oliguria
Postsurgery at RRT initiation		Total APACHE II score	Total APACHE II
Heart rate		Immunosuppressive therapy	Oliguria
Mean arterial pressure
Urine volume
Mechanical ventilation
Fraction of inspired oxygen ≥0.6
Interaction of mechanical ventilation and fraction of inspired oxygen ≥60%
Arterial pH (Z-score)
Arterial oxygen partial pressure
Serum creatinine
Serum bicarbonate
Serum phosphate
Serum albumin
Total bilirubin
International normalized ratio
Platelet count

ATN, Acute renal failure Trial Network; LASSO, least absolute shrinkage and selection operator; APACHE, Acute Physiology and Chronic Health Evaluation.

^aATN variables that were significant at P<0.05 in a multivariable logistic analysis in the Biologic Markers of Recovery for the Kidney cohort.