Rate of Kidney Function Decline and Risk of Hospitalizations in Stage 3A CKD.
OBJECTIVE
Risk of hospitalizations is increased in patients with CKD. We sought to examine the association between rate of kidney function decline and risk of hospitalization in a cohort of patients with early CKD.


METHODS
We built a cohort of 247,888 United States veterans who had at least one eGFR measurement between October 1999 and September 2003 and an additional eGFR between October 2003 and September 2004. We selected patients whose initial eGFR was between 45 and 59 ml/min per 1.73 m2. Rate of eGFR change (in milliliters per minute per 1.73 m2 per year) was categorized as no decline (>0), mild (0 to -1, and served as the referent group), moderate (-1 to -5), or severe (>-5) eGFR decline. We built survival models to examine the association between the rate of kidney function decline and the risk of hospitalization and readmission and linear regression to estimate length of hospital stay.


RESULTS
Over a median observation of 9 years (interquartile range, 5.28-9.00), patients with moderate and severe eGFR decline exhibited a higher risk of hospitalizations (hazard ratio [HR], 1.22; 95% confidence interval [95% CI], 1.19 to 1.26; and HR, 1.33; 95% CI, 1.28 to 1.39, respectively). Among patients with moderate and severe eGFR decline, the association between the rate of decline and the risk of hospitalizations was more pronounced with an increased number of hospitalizations (P<0.01). Patients with moderate and severe eGFR decline had a higher risk of readmission (HR, 1.19; 95% CI, 1.13 to 1.26; and HR, 1.53; 95% CI, 1.43 to 1.63, respectively). Among patients with severe eGFR decline, the association between the rate of kidney function decline and the risk of readmission was stronger with an increased number of readmissions (P<0.01). Patients with moderate and severe eGFR decline experienced an additional length of stay of 1.40 (95% CI, 0.88 to 1.92) and 5.00 days per year (95% CI, 4.34 to 5.66), respectively.


CONCLUSIONS
The rate of kidney function decline is associated with a higher risk of hospitalizations, readmissions, and prolonged length of hospital stay.
Clinical Epidemiology Center and.
Yan
Y
Xie
Clinical Epidemiology Center and.
Benjamin
B
Bowe
Clinical Epidemiology Center and Department of Biostatistics, College for Public Health and Social Justice, Saint Louis University, Saint Louis, Missouri; and.
Hong
H
Xian
Clinical Epidemiology Center and.
Sumitra
S
Balasubramanian
Clinical Epidemiology Center and Division of Nephrology, Department of Medicine, Veterans Affairs Saint Louis Health Care System, Saint Louis, Missouri; Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri zalaly@gmail.com.
Ziyad
Z
Al-Aly
D000368:Aged; D005260:Female; D005919:Glomerular Filtration Rate; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D051436:Renal Insufficiency, Chronic / Q000503:physiopathology* / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index
chronic kidney disease; eGFR slope; glomerular filtration rate; hospitalization; length of stay; patient readmission; renal insufficiency, chronic; risk; united states; veterans