Data Sources


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  • ACS (American Community Survey).

    The American Community Survey (ACS) collects information about the nation and its residents on a yearly basis to help determine how federal and state funds are spent. The ACS provides publicly available data on jobs and occupations, educational attainment, Veteran status, whether people own or rent their homes, and other topics. Data on poverty thresholds for 2015–2019 were taken from the Current Population Survey. Poverty thresholds are calculated by family size and composition.


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  • CDC NCEH (CDC National Environmental Public Health Tracking Network).

    The CDC National Environmental Public Health Tracking Network brings together data and information on environments and hazards, health effects, and population health from national, state, and city sources.

    Fine particulate matter (PM2.5) data is taken from the Center for Disease Control’s (CDC) National Environmental Public Health Tracking Network Downscaler PM2.5 Metadata.


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  • CHR (County Health Ranking).

    The residential segregation index is developed by the County Health Ranking using American Community Survey 5-year estimate data (2017–2021) to assess residential segregation of Black and White residents.


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  • Clinformatics Commercial (Clinformatics Commercial).

    Clinformatics data sets provide paid medical and prescription claims and enrollment information for participants in commercial insurance plans and Medicare Advantage plans. The sample was limited to those enrolled in their health plan for all 12 months of the calendar year. Chronic kidney disease (CKD) and diabetes are defined using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), or Tenth Revision (ICD-10-CM) diagnosis codes. Outpatient pharmacy records of prescriptions filled for patients were examined for drugs in the sodium-glucose cotransporter-2 (SGLT2) inhibitors class. For inclusion in analyses, beneficiaries had to be in the enrollment file. To define CKD, diabetes, or hypertension, at least one inpatient or two outpatient claims were used.


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  • CMS (Centers for Medicare & Medicaid Services - Medicare).

    CMS maintains claims data on beneficiaries aged 65 years and older, those with disabilities, and those with end-stage kidney disease. A 5% random sample of beneficiaries who had at least one inpatient or outpatient visit during the calendar year—over 1.8 million annually—of Medicare claims data was used.

    Diagnoses for medical conditions in Medicare data come from claims submitted by providers for Medicare fee-for-service Part A (hospital insurance) and Part B (medical insurance). The analysis sample was limited to beneficiaries aged 65 years or older who had Parts A and B coverage for the entire calendar year and had at least one inpatient or outpatient visit in that calendar year. Between 20% and 37% of beneficiaries each year used Part C (managed care/Medicare Advantage plans) and are excluded because their care was paid on a fixed amount and claims with diagnoses are unavailable. Chronic kidney disease, diabetes, and hypertension are defined by at least one diagnosis code for each condition.


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  • DoD-MHS (Department of Defense Military Health System).

    The US Department of Defense Military Health System (MHS) provides comprehensive primary and specialty care for more than 9.6 million active-duty personnel and military retirees and their families worldwide. The MHS Data Repository (MDR) is the administrative claims database for all care received through MHS, including direct care received in military treatment facilities and purchased care received in civilian treatment facilities. The MDR does not capture health care delivery in combat zones or care received in the VHA system. All patients were in the TRICARE Prime managed care option. Data are from both the direct care (military facilities) and private care (private facilities through TRICARE coverage) systems.

    De-identified patient data were obtained from the MHS data repository. Data contain both the estimated glomerular filtration rate (eGFR) definition of chronic kidney disease (CKD) and claims-based CKD defined by using ICD-9-CM and ICD-10-CM codes diagnosis codes with at least one inpatient or two outpatient CKD diagnoses. To be included in analyses, service members and their dependents had to have at least one inpatient or outpatient record during the fiscal year (October 1 to September 30). Data cells with 10 or fewer patients were suppressed.

    Disclaimer: The views expressed are those of the authors and do not reflect the official policy of the Uniformed Services University, Departments of Army/Navy/Air Force, Department of Defense, Centers for Disease Control and Prevention, Department of Health and Human Services, or U.S. government.


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  • Medicare (Medicare 5% random sample). Prevalence of Polycystic Kidney Disease (PKD) among Medicare Beneficiaries.
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  • NATIONAL VA (Veterans Affairs Health System).

    VHA is America’s largest integrated health care system, providing care at 171 medical centers and 1,113 outpatient sites. VHA serves over 9 million enrolled Veterans each year. National VHA data were examined for Veterans with at least one outpatient visit during the federal fiscal year (October 1 to September 30). Medical conditions were defined by ICD-9-CM and ICD-10-CM diagnosis codes on at least one outpatient claim.


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  • NHANES (National Health and Nutrition Examination Survey).

    NHANES is a nationally representative, cross-sectional survey that is currently conducted every two years (since 1999) by CDC's National Center for Health Statistics among noninstitutionalized US civilian residents. The survey consists of a standardized in-home interview and a physical examination with blood and urine collected at a mobile examination center. Data were examined by combining two NHANES cycles to represent four-year periods from 2001 to 2016 and the 2017–March 2020 pre-pandemic cycle. 

    Note: Not all NHANES variables are collected for all years; therefore, some NHANES indicators may not utilize the full 20-year span.


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