Measuring Complications of Cancer Treatment Using the SEER-Medicare Data

BACKGROUND: The linkage of SEER registry data with Medicare claims allows the longitudinal tracking of health care and outcomes for patients after a cancer diagnosis. One category of outcomes amenable to research using Medicare claims is complications of cancer treatments: the unintentional, adverse side effects or sequelae of interventions used to treat or palliate cancer patients. RESEARCH DESIGN: The authors review some of the methods and limitations of using Medicare claims to identify both acute and chronic complications of cancer treatments, and present an original analysis comparing survey-based and claims-based complications following radical prostatectomy for prostate cancer to illustrate some of the potential limitations inherent in using claims for this purpose. RESULTS: Utility of the Medicare claims for identifying postdischarge complications varies by the patient type, the initial treatment used, and any subsequent treatment of complications. For patients undergoing surgical interventions, Medicare claims can be used to identify most acute inpatient complications. However, claims data cannot be used as effectively in the long-term to capture chronic complications, particularly when the complication does not consistently prompt an intervention. CONCLUSION: Researchers who use the SEER-Medicare-linked database to assess long-term complications of cancer treatments should exercise caution when designing and interpreting studies. Ideally, for studies of most chronic complications of cancer care, validation studies similar to the one performed here would provide valuable additional evidence to assess the credibility of conclusions based on claims data.