Evaluate algorithms for identifying treatment patterns for patients with metastatic colorectal cancer using administrative claims data.

299 Background: Administrative claims data are widely used to identify treatment patterns. However, as new drugs are brought to clinical practice, treatment regimens become more complicated for cancer patients receiving both chemotherapy and biologic agents. We evaluated the influence of using different treatment length algorithms on identification of treatment patterns for patients with metastatic colorectal cancer (mCRC). Methods: We identified patients aged 18 or older with at least one primary CRC diagnosis between 01/01/2008 and 03/31/2012 in the MarketScan databases. mCRC patients were included if claims indicated the presence of distant metastases (ICD-9-CM codes: 196.x, 197.0 to 197.4, 197.6 to 197.8, 198.x, and 199.0). All treatment claims were extracted and patients were followed for more than 6 months, until end of enrollment or study end date (03/01/2013). We identified all chemotherapy and/or biologic drugs given to a patient during 30, 60, or 90 days after initiation of treatment and compare...