Table 3.

Characteristics predictive of alert harm or benefit among patients in a randomized trial of AKI alerts

Characteristic	Unlikely to Benefit from Alert (n=237)	Likely to Benefit from Alert (n=446)	P Value
Demographics, n (%)
Age, yr	56 (18)	64 (15)	<0.001
Men	165 (71)	211 (47)	<0.001
Black	63 (27)	134 (30)	0.34
In ICU at randomization	72 (30)	121 (27)	0.37
Surgical admission	107 (45)	159 (36)	0.02
Comorbidities, n (%)
Cerebrovascular disease	29 (12)	66 (15)	0.36
CKD	78 (33)	110 (25)	0.02
Congestive heart failure	86 (36.3)	145 (33)	0.32
Diabetes	78 (33)	131 (29)	0.34
Liver disease	42 (18)	60 (14)	0.14
Malignancy	47 (20)	111 (25)	0.14
Metastatic disease	13 (6)	41 (9)	0.09
Laboratory values, median (IQR)
Baseline creatinine, mg/dl	1.15 (0.78–1.69)	0.78 (0.53–1.16)	<0.001
Alert creatinine, mg/dl	1.58 (1.18–2.14)	1.20 (0.86–1.70)	<0.001
Hemoglobin, g/dl	10.4 (9.2–12.0)	10.2 (8.9–11.6)	0.12
Phosphorus, mg/dl	4.2 (3.4–5.1)	3.5 (2.9–4.2)	<0.001
Potassium, meq/L	4.3 (3.9–4.7)	4.2 (3.8–4.5)	0.005
Sodium, meq/L	138 (135–141)	137 (134–140)	0.008
Severity of illness, median (IQR)
SOFA score	2 (1–5)	2 (1–4)	0.08
Medication exposures, n (%)
NSAIDs	13 (5.5)	33 (7.4)	0.34
Vasopressors	41 (17)	82 (18)	0.73
Loop diuretic	81 (34)	163 (37)	0.54
ACE inhibitor/angiotensin receptor blocker	40 (17)	97 (22)	0.13
Antibiotics	142 (60)	295 (66)	0.11
Intravenous contrast	37 (16)	108 (24)	0.009
Randomization status, n (%)
Alert	126 (53)	222 (50)	0.46

Characteristics at randomization of patients in the test set predicted to be unlikely to benefit from alert versus likely to benefit from alert on the basis of Z-Learner score ≤0 or >0, respectively. Note that comorbidity codes and medication exposures are not used in model building and are produced here to provide a clearer clinical phenotype for readers. Data are n (%) or median (interquartile range [IQR]). ICU, intensive care unit; SOFA, Sequential Organ Failure Assessment; NSAIDs, nonsteroidal anti-inflammatory drugs; ACE, angiotensin-converting enzyme.