Finding and Using Health Statistics

3. Health Data Sources

Claims Data

Claims data, also known as administrative data, are another sort of electronic record, but on a much bigger scale. Claims databases collect information on millions of doctors’ appointments, bills, insurance information, and other patient-provider communications.

The good thing about claims data is that, like other medical records, they come directly from notes made by the health care provider, and the information is recorded at the time patient sees the doctor. Also, because of the large sample size of claims data, researchers can analyze groups of patients with rare illnesses and medical conditions. The downside to using claims data is that there may be low validity due to certain illegal billing practices, like ordering unnecessary tests or billing for services that were not provided.

Several claims databases are available including claims data from the Centers for Medicare and Medicaid Services (CMS). Currently, the Agency for Healthcare Research and Quality (AHRQ) is developing an all-payer claims database, which would compile the medical claims, pharmacy claims, dental claims, and eligibility and provider files from private and public payers. This information is already reported at the state level, but AHRQ aims to develop a complete database that would advance research in health care affordability, and cost transparency.1

For example, the data from these graphs are from the CMS Chronic Conditions Public Use Files, a source of claims data.2

Table 3: Average Payment per Enrollee for Medicare Part A & B by Number of Chronic Conditions

Hospital Insurance (Part A) Average Cost

Line graph showing that as the number of chronic conditions rise, having medicare only as opposed to medicare and medicaid is a higher cost.

Medical Insurance (Part B) Average Cost

Line graph that shows as the number of chronic conditions increase, the cost for medicare and medicaid is greater than just medicare only.

1. "All-Payer Claims Databases." Agency for Healthcare Research and Quality, Feb. 2018,

2. Erdem, Erkan et al. "Medicare payments: How much do chronic conditions matter?." Medicare & Medicaid Research Review. Vol. 3,2 MMRR. 003.02.b02. 18 Jun. 2013,