Table 1

Patient characteristics at the time of study consent and selected 12-month outcomes

Non-HCUHCUP value*
Not admittedAdmitted
n24482139509
Male, n (%)1319 (53.9)1146 (53.6)282 (55.4)0.475
Indigenous, n (%)125 (6.5)133 (8.1)32 (8.5)0.384
Age, mean years (SD)63 (15.9)66.1 (15)69.1 (13.1)0.000
Age band, n (%)0.000
 <40260 (10.6)154 (7.2)15 (3)
 40–49235 (9.6)163 (7.6)32 (6.3)
 50–59381 (15.6)295 (13.8)62 (12.2)
 60–69605 (24.7)519 (24.3)130 (25.5)
 70–79671 (27.4)659 (30.8)167 (32.8)
 ≥80296 (12.1)349 (16.3)103 (20.2)
BMI, mean (SD)31.3 (7.8)31.1 (7.7)31.4 (8.8)0.788
BMI group0.425
 ≤18.516 (1)19 (1.3)5 (1.5)
 18.5–25258 (15.7)231 (16.3)63 (19.2)
 25–30484 (29.5)415 (29.3)90 (27.4)
 >30885 (53.9)752 (53.1)170 (51.8)
eGFR, mean (SD)44.8 (21.9)37.3 (20.5)33.2 (17.8)0.000
CKD stage, n (%)0.000
 1–2509 (21.6)261 (12.8)40 (8.3)
 31224 (52)963 (47.1)210 (43.6)
 4521 (22.1)585 (28.6)178 (36.9)
 5101 (4.3)236 (11.5)54 (11.2)
Primary renal diagnosis, n (%)0.000
 Diabetic nephropathy472 (20.9)503 (26.1)157 (33.2)0.000
 Glomerulonephritis338 (14.9)227 (11.8)40 (8.5)0.002
 Renovascular667 (29.5)634 (32.8)134 (28.3)0.231
 Other787 (34.8)567 (29.4)142 (30)0.319
Comorbidities, n (%)
 Diabetes952 (46.5)974 (54.5)262 (63.6)0.000
 CVD599 (38)761 (56.5)229 (71.3)0.000
 Hypertension1376 (78.7)1208 (81)309 (86.3)0.003
Multi-comorbidity status, n (%)
 Diabetes and CVD327 (13.4)444 (20.8)147 (28.9)0.000
 Diabetes and hypertension598 (24.4)633 (29.6)178 (35)0.000
 CVD and hypertension502 (20.5)650 (30.4)209 (41.1)0.000
 Diabetes, CVD and hypertension279 (11.4)393 (18.4)135 (26.5)0.000
Selected outcomes at 12 months, n (%)
 ≥5 inpatient admissions0 (0)138 (6.5)260 (51.1)0.000
 Admitted for dialysis†0 (0)13 (0.6)7 (1.4)0.000
 Renal replacement therapy0 (0)135 (6.3)37 (7.3)0.000
 Death27 (1.1)95 (4.4)99 (19.5)0.000
Selected cost outcome statistics
 A$, mean (SD)0 (0)8091 (7155)63 828 (42 200)0.000
 A$, median (IQR)0 (0)5734 (9656)50 588 (34 068)0.000
 Skewness01.00242.761
  • The non-HCU group comprises of those never admitted, and those admitted at least once. The three groups reported in the table are mutually exclusive.

  • Statistical significance denoted in bold for p-values < 0.05.

  • *T-test (continuous), Pearson’s χ2 (categorical) or Wilcoxon rank-sum test (medians) comparing HCU versus non-HCU.

  • †Admissions with DRG code L61Z or L68Z.

  • BMI, body mass index; CVD, cardiovascular disease; DRG, diagnosis-related group; eGFR, estimated glomerular filtration rate; HCU, high-cost user.