Linking Tumor Registry and Medicaid Claims
to Evaluate Cancer Care Delivery

The utility of Medicaid claims for
studying cancer care is not known. Our
objective was to evaluate how well Medicaid
claims capture diagnostic and treatment
information recorded by the California
Cancer Registry (CCR). We compared
cancer treatment from Medicaid claims
with CCR data, using 1988-2000 cases
matched with 1997-1998 Medicaid enrollment
data. Medicaid claims corroborated
diagnoses for 73 percent of breast and
68 percent of colorectal cancers in CCR.
Medicaid claims confirmed surgery for 67
percent of CCR’s breast cancers. We found
that Medicaid claims have moderate sensitivity
for identifying cancer diagnoses and
surgery. Linked registry-Medicaid data can
identify indigent patients and the timing of
Medicaid coverage.