Table 4.

Risk of study outcomes among patients surviving their index hospital admission in Washington State from 2006 (second quarter) to 2008 by CKD stage in a fully adjusted Cox proportional hazards model (n=27,870)

Hazard
Ratio99% CIPTime to First Hospitalization (Months)Full Study First HospitalizationWithin First Month First Hospitalization
MedianIQRNPercentnPercent
Subsequent hospitalization
 CKD stage unspecified1.201.17–1.22<0.00141–1113,73161.8467221.0
 CKD stage 1 and 21.110.99–1.240.0251–1253457.815717.0
 CKD stage 31.121.15–1.20<0.00141–11157855.951918.4
 CKD stage 41.401.29–1.52<0.00131–894464.432522.2
 CKD stage 51.771.53–2.04<0.00131–932871.110823.4
 reference1.0051–13268,80841.984,74513.2
 total CKD1.201.18–1.23<0.00141–1117,09861.3578120.7
Fatal hospitalization
 CKD stage unspecified1.411.53–1.49<0.00193–182,32210.54161.9
 CKD stage 1 and 21.000.72–1.340.98134–23636.880.9
 CKD stage 31.261.06–1.49<0.00182–172338.3491.7
 CKD stage 41.871.54–2.27<0.00162–1618112.3352.4
 CKD stage 52.451.76–3.42<0.00183–156113.2102.2
 reference1.0092–1922,4323.544370.7
 total CKD1.411.34–1.49<0.00192–18286010.35181.9
  • The CKD cohort did not include patients treated by hemodialysis, peritoneal dialysis, or kidney transplant. 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. CI, confidence interval; IQR, interquartile range.