Understanding the County-level Variability in the Prevalence of Diagnosed Chronic Kidney Disease (CKD) in the Medicare Population across the United States (US)

Bragg-Gresham, Jennifer

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298122
Understanding the County-level Variability in the Prevalence of Diagnosed Chronic Kidney Disease (CKD) in the Medicare Population across the United States (US)

142nd APHA Annual Meeting and Exposition (November 15 - November 19, 2014): http://www.apha.org/events-and-meetings/annual

Tuesday, November 18, 2014 : 8:50 AM - 9:10 AM

Jennifer Bragg-Gresham, PhD , School of Public Health, University of Michigan, Ann Arbor, MI

Hal Morgenstern, PhD , Departments of Epidemiology, Environmental Health Sciences, and Urology, University of Michigan, Ann Arbor, MI

Sharon Saydah, PhD , Centers for Disease Control, Hyattsville, MD

Desmond Williams, MD, PhD , Division of Diabetes Translation, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA

Neil Powe, MD, MPH, MBA , Department of General Internal Medicine and Center for Vulnerable Populations at San Francisco General Hospital, University of California San Francisco, San Francisco, CA

Delphine Tuot, MD , Division of Nephrology at San Francisco General Hospital, University of California, San Francisco, San Francisco, CA

Yi Li, PhD , School of Public Health, Department of Biostatistics, University of Michigan, Ann Arbor, MI

Rajiv Saran, MD, MS , School of Medicine, Department of Nephrology, University of Michigan, Ann Arbor, MI

Large geographic variation exists in the crude prevalence of CKD across the US. Although some of this variation is likely explained by differences in individual-level risk factors, we hypothesized that some of the remaining variation would be explained by county-level characteristics.

Using data on 1.1+ million persons from the 2010 5% Medicare sample, we examined associations between diagnosed CKD by claims, and both individual-level risk factors (age, sex, race, diabetes, hypertension) and county-level variables (urban/rural, number of physicians, etc.). County-specific CKD prevalence was estimated by mixed logistic regression, treating counties as random effects, in three models: unadjusted, adjusted for individual risk factors, and adjusted for both individual and county-level factors. Modified Poisson regression was used to calculate associations (prevalence ratios) between each covariate and CKD prevalence. Model fits were compared using likelihood ratio tests.

Crude prevalence of diagnosed CKD ranged from 0%-60% among counties (median=16%). Interquartile ranges decreased from 2.4% when unadjusted to 1.6% when adjusted for individual risk factors to 1.4% when adjusted for individual and county-level factors. Model fit was improved with each level of adjustment (p<0.0001). In adjusted models, the following county-level measures were associated with greater prevalence of diagnosed CKD (p<0.01): fewer hospitals/population; fewer physicians/population; fewer fitness centers/population; poor air quality; and urban (vs. rural) county.

These results suggest that county-level factors may help explain geographic variability in diagnosed CKD prevalence among the US Medicare population. This might lead to new insights and direct appropriate public health action to geographic areas where it is most needed

Learning Areas:

Assessment of individual and community needs for health education
Chronic disease management and prevention
Epidemiology
Public health or related research

Learning Objectives:
Assess the degree of geographic variability in diagnosed CKD by county as part of the US CDC�s National CKD Surveillance System project. Evaluate potential reasons for geographic variability in prevalence of diagnosed CKD across US counties. Evaluate the association between potentially modifiable county-level characteristics and the prevalence of diagnosed CKD. Demonstrate feasibility of using Medicaid data and county-level estimates to examine geographic variability of chronic health conditions and diseases.

Keyword(s): Epidemiology, Urban Health

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have conducted research in the areas of chronic kidney disease and end-stage renal disease for over 15 years as both a Biostatistican and now Epidemiologist. I am particularly interested in improving the awareness and slowing the progression of chronic kidney disease.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.

Back to: 4016.0: Healthography: Spatial and geographical statistics in public health

142nd APHA Annual Meeting and Exposition

Online Program

298122 Understanding the County-level Variability in the Prevalence of Diagnosed Chronic Kidney Disease (CKD) in the Medicare Population across the United States (US)

298122
Understanding the County-level Variability in the Prevalence of Diagnosed Chronic Kidney Disease (CKD) in the Medicare Population across the United States (US)