Table 2.

Risk of subsequent hospitalization among patients surviving their index hospital admission in Washington State from 2006 (second quarter) to 2008 in a fully adjusted Cox proportional hazards model (n=676,343)

Subsequent Hospitalization
Hazard Ratio99% CIPTime to First Hospitalization (Months)Full Study First HospitalizationsWithin First Month First Hospitalization
MedianIQRnPercentnPercent
Cohort
 CKD1.201.18–1.23<0.00141–1117,09561.3577320.7
 dialysis1.761.69–1.83<0.00131–8445372.6156025.4
 kidney transplant1.851.68–2.03<0.00141–1273666.921219.3
 reference1.0051–13268,80841.984,74513.2
All cohorts51–13291,09243.092,29013.6
  • Fully adjusted model controlling for age; sex; index hospitalization primary diagnosis, length of stay, and primary payer; 12-month count of previous hospitalizations; and Elixhauser comorbidity variables. CKD cohort defined by CKD not treated with hemodialysis, peritoneal dialysis, or kidney transplant. Dialysis cohort includes hemodialysis and peritoneal dialysis. CI, confidence interval; IQR, interquartile range.