Table 1.

Demographic comparison of patients with higher versus lower likelihood of missing baseline serum creatinine data among those with known baseline creatinine data, as indicated by propensity score analysis

Baseline CharacteristicsHigher Likelihood of Missing Baseline SCr (n=6502)Lower Likelihood of Missing Baseline SCr (n=6501)Total (n=13,003)
Median age (yr)54 (40–67)62 (53–71)59 (46–69)
Men, n (%)3250 (50)2858 (44)6108 (47)
Ethnicity, n (%)
 White5388 (83)5417 (83)10,805 (83)
 African-American798 (12)950 (15)1,748 (13)
 Other316 (5)134 (2)450 (4)
Diabetes mellitus, n (%)536 (8)2334 (36)2870 (22)
Hypertension, n (%)1133 (17)4721 (73)5854 (45)
Coronary artery disease, n (%)1070 (16)2042 (31)3112 (24)
Chronic heart failure, n (%)403 (6)1609 (25)2012 (15)
Cerebrovascular disease, n (%)587 (9)1458 (22)2045 (16)
Peripheral vascular disease, n (%)162 (2)887 (14)1049 (8)
Chronic liver disease, n (%)117 (2)727 (11)844 (6)
Charlson comorbidity index0 (0–2)6 (2–12)2 (0–6)
Admission service, n (%)
 Medical3339 (51)4319 (66)7658 (59)
 Surgical2853 (44)1924 (30)4777 (37)
 Other/mixed310 (5)258 (4)568 (4)
Home distance from hospital (miles)40 (15–100)25 (10–70)35 (10–80)
Length of hospital stay (d)a3.3 (2.1–6.0)3.2 (2.1–5.3)3.3 (2.1–5.7)
Baseline creatinine (mg/dl)0.90 (0.76–1.10)1.00 (0.80–1.30)0.95 (0.80–1.20)
Baseline eGFR (ml/min per 1.73 m2)83 (67–102)70 (52–89)77 (59–95)
AKI (%)958 (15)1582 (24)2540 (20)
Died within 60 d (%)259 (4)658 (10.0)917 (7)
  • All values are expressed as n (%) or median (interquartile range). P<0.001 for differences between missing baseline and available baseline serum creatinine groups for all characteristics listed except as noted. SCr, serum creatinine; eGFR, estimated GFR.

  • a P=0.05.