How the SEER, CAHPS, and Medicare Data are Linked

The linkage of the SEER-CAHPS data is a collaborative effort of the NCI, the SEER registries, and the Centers for Medicare & Medicaid Services (CMS). NCI and CMS establish the linkages between the three data sources (SEER clinical data, Medicare claims, and CAHPS survey data); it is not the responsibility of investigators seeking to use the data. The linkage process is described below:

• To link SEER with Medicare data, the registries participating in the SEER program send individual identifiers for all persons in their files. These identifiers are matched with identifiers contained in Medicare's master enrollment file.
• CAHPS survey data are then matched to beneficiaries in the SEER registry using the same identifiers. CAHPS data from beneficiaries who did not have cancer according to SEER data but resided in a SEER region for at least 1 day, either in the year that they completed the CAHPS survey or in the year prior, were also linked to Medicare claims from CMS.

A small number of beneficiaries completed more than one CAHPS survey, resulting in a slightly greater number of surveys than individual beneficiaries. The linkage of CAHPS data to the SEER-Medicare database was first completed in 2011 and is updated approximately every 2-3 years based on SEER and other data availability.

The process for linking CAHPS data to SEER and Medicare data is described in greater detail in:

• Chawla N, Urato M, Ambs A, Schussler N, Hays RD, Clauser SB, Zaslavsky AM, Walsh K, Schwartz M, Halpern M, Gaillot S, Goldstein EH, Arora NK. Unveiling SEER-CAHPS: a new data resource for quality of care research. J Gen Intern Med 2015 May;30(5):641-50. [View Abstract] [Full Text]