Validation Study of Medicare Claims to Identify Older US Adults With CKD Using the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study

• Type of Material: Article
• Authors: Paul Muntner, University of Alabama at Birmingham; Orlando M. Gutiérrez, University of Alabama at Birmingham; Hong Zhao, University of Alabama at Birmingham; Caroline S. Fox, Brigham and Women’s Hospital; Nicole C. Wright, University of Alabama at Birmingham; Jeffrey R. Curtis, University of Alabama at Birmingham; William McClellan, Emory University; Henry Wang, University of Alabama at Birmingham; Meredith Kilgore, University of Alabama at Birmingham; David G. Warnock, University of Alabama at Birmingham; Christopher Bowling, Emory University
• Language: English
• Date: 2015-02-01
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2015 National Kidney Foundation, Inc.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1053/j.ajkd.2014.07.012
• Title of Journal or Parent Work: American Journal of Kidney Diseases
• ISSN: 0272-6386
• Volume: 65
• Issue: 2
• Start Page: 249
• End Page: 258
• Grant/Funding Information: This research project is supported by a cooperative agreement U01 NS041588 from the National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Department of Health and Human Services and R01 HS018517 from the Agency for Healthcare Research and Quality.; Additional funding was provided by an investigator-initiated grant-in-aid from Amgen Corporation to Dr Warnock.; Additional support was provided through the National Institute on Aging (grant R03AG042336) and the T. Franklin Williams Scholarship Award (funding provided by Atlantic Philanthropies, Inc, the John A. Hartford Foundation, the Association of Specialty Professors, the American Society of Nephrology and the American Geriatrics Society) to Dr Bowling.
• Keywords: Science & Technology; specificity; RISK; albuminuria; COLLABORATIVE METAANALYSIS; MORTALITY; POPULATION COHORTS; predictive value; claims-based algorithm; estimated glomerular filtration rate (eGFR); UNITED-STATES; sensitivity; Urology & Nephrology; ADMINISTRATIVE DATA; Life Sciences & Biomedicine; end-stage renal disease (ESRD); health care claims data; ALL-CAUSE; Chronic kidney disease (CKD)
• Research Categories: Health Sciences, Epidemiology; Health Sciences, Medicine and Surgery

Abstract

Background: Health care claims data may provide a cost-efficient approach for studying chronic kidney disease (CKD). Study Design: Prospective cohort study. Setting & Participants: We compared characteristics and outcomes for individuals with CKD defined using laboratory measurements versus claims data from 6,982 REGARDS (Reasons for Geographic and Racial Differences in Stroke) Study participants who had Medicare fee-for-service coverage. Predictors: Presence of CKD as defined by both the REGARDS Study (CKDREGARDS) and Medicare data (CKDMedicare), presence of CKDREGARDS but not CKDMedicare, and presence of CKDMedicare but not CKDREGARDS, and absence of both CKDREGARDS and CKDMedicare. Outcomes: Mortality and incident end-stage renal disease (ESRD). Measurements: The research study definition of CKD (CKDREGARDS) included estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 or albumin-creatinine ratio > 30 mg/g at the REGARDS Study visit. CKD in Medicare (CKDMedicare) was identified during the 2 years before each participant's REGARDS visit using a claims-based algorithm. Results: Overall, 32% of participants had CKDREGARDS and 6% had CKDMedicare. Sensitivity, specificity, and positive and negative predictive values of CKDMedicare for identifying CKDREGARDS were 15.5% (95% CI, 14.0%-17.1%), 97.7% (95% CI, 97.2%-98.1%), 75.6% (95% CI, 71.4%-79.5%), and 71.5% (95% CI, 70.4%-72.6%), respectively. Mortality and ESRD incidence rates, expressed per 1,000 person-years, were higher for participants with versus without CKDMedicare (mortality: 72.5 [95% CI, 61.3-83.7] vs 33.3 [95% CI, 31.5-35.2]; ESRD: 16.4 [95% CI, 11.2-21.6] vs 1.3 [95% CI, 0.9-1.6]) and with versus without CKDREGARDS (mortality: 59.9 [95% CI, 55.4-64.4] vs 25.5 [95% CI, 23.6-27.4]; ESRD: 6.8 [95% CI, 5.4-8.3] vs 0.1 [95% CI, 0.0-0.3]). Among participants with CKDREGARDS, those with abdominal obesity, diabetes, anemia, lower eGFR, more outpatient visits, hospitalization, and a nephrologist visit in the 2 years before their REGARDS visit were more likely to have CKDMedicare. Limitations: CKDREGARDS relied on eGFR and albuminuria assessed at a single visit. Conclusions: CKD, whether defined in claims or through research study measurements, was associated with increased mortality and ESRD. However, individuals with CKD identified in claims may represent a select high-risk population.