Assessing Cancer Treatment Information Using Medicare and Hospital Discharge Data among Women with Non-Hodgkin Lymphoma in a Los Angeles County Case-Control Study.

BACKGROUND

We assessed the ability to supplement existing epidemiologic/etiologic studies with data on treatment and clinical outcomes by linking to publicly available cancer registry and administrative databases.

METHODS

Medical records were retrieved and abstracted for cases enrolled in a Los Angeles County case-control study of non-Hodgkin lymphoma (NHL). Cases were linked to the Los Angeles County cancer registry (CSP), the California state hospitalization discharge database (OSHPD), and the SEER-Medicare database. We assessed sensitivity, specificity, and positive predictive value (PPV) of cancer treatment in linked databases, compared with medical record abstraction.

RESULTS

We successfully retrieved medical records for 918 of 1,004 participating NHL cases and abstracted treatment for 698. We linked 59% of cases (96% of cases >65 years old) to SEER-Medicare and 96% to OSHPD. Chemotherapy was the most common treatment and best captured, with the highest sensitivity in SEER-Medicare (80%) and CSP (74%); combining all three data sources together increased sensitivity (92%), at reduced specificity (56%). Sensitivity for radiotherapy was moderate: 77% with aggregated data. Sensitivity of BMT was low in the CSP (42%), but high for the administrative databases, especially OSHPD (98%). Sensitivity for surgery reached 83% when considering all three datasets in aggregate, but PPV was 60%. In general, sensitivity and PPV for chronic lymphocytic leukemia/small lymphocytic lymphoma were low.

CONCLUSIONS

Chemotherapy was accurately captured by all data sources. Hospitalization data yielded the highest performance values for BMTs. Performance measures for radiotherapy and surgery were moderate.

IMPACT

Various administrative databases can supplement epidemiologic studies, depending on treatment type and NHL subtype of interest.