Background: Most data regarding medical care for cancer patients in the United States comes from Surveillance, Epidemiology and End Results-linked Medicare analyses of individuals aged 65 years or older and typically excludes Medicare Advantage enrollees.
Objectives: To assess the accuracy of chemotherapy and hormone therapy treatment data available through the Cancer Research Network's Virtual Data Warehouse (VDW).
Research design: Retrospective, longitudinal cohort study. Medical record-abstracted, tumor registry-indicated treatments (gold standard) were compared with VDW-indicated treatments derived from health maintenance organization pharmacy, electronic medical record, and claim-based data systems.
Subjects: Enrollees aged 18 years and older diagnosed with incident breast, colorectal, lung, or prostate cancer from 2000 through 2007.
Measures: Sensitivity, specificity, and positive predictive value were computed at 6 and 12 months after cancer diagnosis.
Results: Approximately 45% of all cancer cases (total N=23,800) were aged 64 years or younger. Overall chemotherapy sensitivity/specificities across the 3 health plans for incident breast, colorectal, lung, and prostate cancer cases were 95%/90%, 95%/93%, 93%/93%, and 85%/77%, respectively. With the exception of prostate cancer cases, overall positive predictive value ranged from 86% to 89%. Small variations in chemotherapy data accuracy existed due to cancer site and data source, whereas greater variation existed in hormone therapy capture across sites.
Conclusions: Strong concordance exists between gold standard tumor registry measures of chemotherapy receipt and Cancer Research Network VDW data. Health maintenance organization VDW data can be used for a variety of studies addressing patterns of cancer care and comparative effectiveness research that previously could only be conducted among elderly Surveillance, Epidemiology and End Results-Medicare populations.