Predicting the Risk of Dialysis and Transplant Among Patients With CKD: A Retrospective Cohort Study
Received 13 September 2007; accepted 17 April 2008. published online 01 July 2008.
Refers to article:
Predicting Outcomes in CKD
Tobias Kurth, Robert J. Glynn
American Journal of Kidney Diseases
October 2008 (Vol. 52, Issue 4, Pages 635-637) Full Text |
Full-Text PDF (75 KB)
Background
Providers need a reliable way to identify patients with chronic kidney disease (CKD) at the highest risk of progression to end-stage renal disease so they can intervene to slow progression and refer patients to nephrology for comanagement. We developed a risk score to predict the 5-year risk of renal replacement therapy (RRT) in patients with stage 3 or 4 CKD.
Study Design
Retrospective cohort study.
Setting & Participants
Participants were members of a health maintenance organization and met Kidney Disease Outcomes Quality Initiative criteria for stage 3 or 4 CKD during 1999 or 2000: two estimated glomerular filtration rate values of 15 to 59 mL/min/1.73 m2.
Predictor
Characteristics collected during routine clinical practice.
Outcomes & Measurements
We ascertained the onset of RRT (dialysis or kidney transplantation) using the health maintenance organization databases. Cox regression predicted patient risk of RRT and generated a risk scoring system.
Results
9,782 patients experienced a 3.3% five-year progression to RRT (95% confidence interval, 2.9 to 3.7). Using 6 characteristics (age, sex, estimated glomerular filtration rate, diabetes, anemia, and hypertension), the risk score discriminated the highest risk patients effectively: 19.0% of patients in the highest risk quintile experienced progression, and 0.2% of patients in the lowest risk quintile experienced progression. The c statistic also showed effective discrimination: 0.89 on a scale of 0.5 to 1.0. Predicted and observed risks agreed within 1.0%—effective calibration. We present a range of predicted risk cutoff values from 1% to 20% and their test properties for decision makers' consideration.
Limitations
Characteristics were measured without a protocol.
Conclusions
The risk score can help providers identify patients with CKD at the highest risk of progression to improve referral to nephrology for comanagement. A separate risk score for mortality also is needed.
1Center for Health Research, Kaiser Permanente Northwest, Portland, OR
2Department of Nephrology, Kaiser Permanente Northwest, Portland, OR
3McGill University Health Centre Research Institute, Montreal, Quebec, Canada
Address correspondence to David H. Smith, RPh, PhD, Center for Health Research, Kaiser Permanente Northwest, 3800 North Interstate Ave, Portland, OR 97227
ABSTRACT