Dartmouth Atlas of Health Care

These data document variations in how medical resources are distributed and used in the United States. The project uses Centers for Medicare and Medicaid Services (CMS) data to provide information and analysis about national, regional and local markets. Measures are available at various levels (e.g., Hospital Referral Region (HRR), Hospital Service Area (HSA), State and County) and for time periods starting in the 1990s. Each set of files includes a data dictionary.  Data files focus on Medicare beneficiaries ages 65 and older. Visit dartmouthatlas.org or https://dataverse.dartmouth.edu/dataverse/atlas for further information. The individual datasets are listed below.

These data were added to the GLR in June 2024.

Care for Chronically Ill (Last 2 Years)

Includes files with measures related to end-of-life care for beneficiaries with fee-for-service (FFS) Medicare who were diagnosed with a chronic illness in the last two years of life. Measures include total Medicare spending, days in hospital, days in intensive care, physician and medical specialist visits, and percentage of deaths in the hospital and beneficiaries in hospice care, by HRR and State.  Rates are provided for all chronic conditions combined and for cancer for 2001-2019

End-of-Life Inpatient Care

Includes files with measures related to end-of-life inpatient care for beneficiaries with fee-for-service (FFS) Medicare in the last six months of life. Measures include total inpatient spending, days in the hospital, days in intensive care, and percentage of deaths in the hospital, by HRR, HSA, State and County. Rates are provided for all deaths combined for 1994-2019 and also by race and gender for 2008-2019.

Hospital and Physician Capacity

Includes a variety of measures of hospital and physician capacity by geography using data from the American Hospital Association, the CMS Provider of Services files, CMS Cost Reports, the American Medical Association, and the American Osteopathic Association. Rates are provided at the hospital referral region (HRR) and hospital service area (HSA) levels; hospital capacity measures are available for 1996, 2006, and 2012, while physician capacity measures are available for 1996, 2006, and 2011.

Medical and Surgical Discharge Rates

Includes files with a wide variety of medical and surgical discharge rates for fee-for-service (FFS) Medicare beneficiaries, age 65 and older, discharged from hospitals for medical and surgical conditions by HRR, HSA, State and County. For the 2008-2014 period, the rates provided for each geographic area include overall annual rates, rates stratified by race (black and non-black), and rates stratified by gender (male and female). For 1992-2007 and 2015, only the overall annual rates are provided. In addition, this entry provides national and region-specific rate data for FFS Medicare beneficiaries for treatments related to eight different “preference-sensitive conditions.” The national rates are based on 2003-2008 data, while regional rates are based on 2008-2010 data.

Medicare Reimbursements

Includes longitudinal and single year files with Medicare expenditures. Longitudinal files are based on CMS Claims. 100% sample-based claims available for 2011-2019 and 20% sampled-based claims available for 2003-2010 by HRR, HSA, State and County. Single year measures for 1992-2007 are based on the Continuous Medicare History Sample (CMHS), the original 5% sample used for Atlas reimbursement data, by HRR, HSA and State.

Mortality

Includes files with measures related to mortality among beneficiaries who are ages 65 and older. Measures include overall, HMO beneficiary, and FFS beneficiary mortality rates by HRR, HSA, and State for 1999-2019.

Post-Discharge Events

Includes files with measures related to post-discharge events for beneficiaries with fee-for-service (FFS) Medicare who were discharged from hospitals for medical and surgical conditions. Measures include the percentage readmitted within 30 days, visiting the emergency room within 30 days, seeing a primary care clinician and any clinician within 14 days by HRR, HSA, State, and County. Rates are provided for six different condition groups (medical conditions, surgical conditions, hip fracture, congestive heart failure, acute myocardial infarction, pneumonia) for 2009-2019.

Primary Care Access and Quality Measures

Includes files with measures related to access and quality of primary care visits. Measures include quality of care for diabetic patients, mammography rates, and hospitalization rates for ambulatory care sensitive conditions, by HRR, HSA, State, and County. Rates are provided overall and by race group for 2003-2019.

Supplemental Files

The ZIP code to HSA to HRR crosswalk files allow researchers to aggregate data at the ZIP code level to the hospital service area (HSA) or hospital referral region (HRR) level. They cover the years 1995-2019. A crosswalk between HSA and HRR IDs is also provided.