Use of the Medicare database in epidemiologic and health services research: a valuable source of real-world evidence on the older and disabled populations in the US

Figures & data

Figure 1 Number of publications using Medicare administrative claims by year, 1979–2016.

Notes: Results of a PubMed search using the following criteria: (Medicare) AND [(“administrative claims”) OR (“administrative data”) OR (“claim data”)] AND not a “review” publication type.

Table 1 Medicare coverage and the corresponding research files available to researchers

Medicare coverage	Research file	Source of claim	Type of claim	Available fields	Medical coding type
Any coverage	Master beneficiary Summary file	Beneficiary enrollment	Not a claim; includes demographic and enrollment information	Number of months of Parts A, B, C, and D coverage Part D plan type Receipt of Part D subsidies Demographic and geographic information Date of death	NA
Part A	Inpatient file Skilled nursing facilities file Home health agency file Hospice file	Inpatient hospitalizations Care received in SNF’s Home health care Hospice care	Institutional claims	Diagnoses and services received by patient in the inpatient, SNF, home health, and hospice setting	Diagnosis-related group ICD-9 diagnosis ICD-10 diagnosis Procedure codes: CPT and HCPC
Part B	Carrier file Outpatient file Durable medical equipment file Home health care file	Physician inpatient and outpatient services Outpatient services Equipment purchased from DME supplier Home health care	Physician and supplier service claims Facility claims Supplier claim Supplier claim	Diagnoses and services received by patient in the inpatient and outpatient setting Services rendered in the outpatient setting Supplies Services rendered in the home health care setting	ICD-9 diagnosis ICD-10 diagnosis Procedure codes: CPT and HCPC
Part D	Prescription drug event file	Prescriptions filled by beneficiary	Retail pharmacy claims	Type of medication Amount dispensed Date of dispensation	National Drug Code

Abbreviations: CPT, current procedural terminology; HCPC, Health and Care Professions Council; ICD, International Classification of Diseases; SNF, skilled nursing facility.

Figure 2 Impact of the expansion of Medicare diagnosis fields in 2010.

Notes: (A) Average number of diagnosis codes per inpatient claim in Medicare 1995–2013. (B) Percent of inpatient claims with a coronary atherosclerosis code using all diagnosis fields (black line) versus limiting to the first 9 fields (red line) 2005–2013.
Abbreviation: IP, inpatient.