Table 2.

Length of stay by AKI status in adults hospitalized in Alberta between 2002 and 2009 (95% confidence interval)

Time PeriodaNo AKIAKIN 1AKIN 2AKIN 3 without DialysisAKIN 3 with Dialysis
(1) Index hospitalization
 No. of subjects (%)206,650 (86.2)25,495 (10.6)4598 (1.9)2493 (1.0)670 (0.3)
 LOS8.9 (8.9 to 9.0)11.4 (11.3 to 11.6)12.8 (12.4 to 13.1)13.7 (13.2 to 14.2)16.5 (15.3 to 17.6)
 Incremental LOS+2.5 (1.0 to 4.1)+3.8 (2.8 to 4.9)+4.8 (4.1 to 5.5)+7.6 (7.4 to 7.8)
(2) Admission to assessment of kidney recovery or 90 db
 No. of subjects (%)206,501 (86.2)25,482 (10.6)4595 (1.9)2491 (1.0)670 (0.3)
 Hospitalization days11.0 (10.9 to 11.0)13.8 (13.7 to 14.0)15.0 (14.6 to 15.5)16.0 (15.4 to 16.7)18.4 (17.0 to 19.7)
 Incremental hospitalization days+2.8 (1.4 to 4.3)+4.0 (3.2 to 4.9)+5.0 (4.5 to 5.6)+7.4 (7.2 to 7.5)
No AKIAKIN 1–3 without DialysisAKIN 3 with Dialysis
RecoveredNot RecoveredRecoveredNot Recovered
(3) Assessment of kidney recovery or 90 d to 1 yrc
 No. of subjects (%)191,921 (88.2)12,558 (5.8)4134 (1.9)181 (0.1)72 (0.03)
 Hospitalization days4.4 (4.3 to 4.4)4.9 (4.7 to 5.1)4.8 (4.5 to 5.0)4.9 (2.9 to 6.9)5.9 (4.1 to 7.8)
 Incremental hospitalization days+0.6 (−0.8 to 1.9)+0.4 (−0.8 to 1.6)+0.5 (0.4 to 0.6)+1.6 (1.5 to 1.7)
  • AKIN, Acute Kidney Injury Network; LOS, length of stay; —, not applicable.

  • a Adjusted for age, sex, Charlson comorbidities (14 variables), hospitalization primary diagnosis (case mix group including ten variables), baseline eGFR, and albuminuria.

  • b In total, 167 (0.1%) patients with outmigration during this period were excluded from analysis.

  • c In total, 20,957 (8.7%) subjects died between admission and recovery of renal function, and 1406 (0.6%) subjects outmigrated and were excluded from analysis.