Accuracy of Medicare claims for identifying findings and procedures performed during colonoscopy.

BACKGROUND: Administrative claims data are frequently used for quality measurement.
OBJECTIVE: To examine the accuracy of administrative claims for potential colonoscopy quality measures, including findings (polyp or tumor detection), procedures (biopsy or polypectomy), and incomplete colonoscopy.
DESIGN: Cross-sectional study. PATIENTS: Patients age 65 and older undergoing colonoscopy in the Clinical Outcomes Research Initiative National Endoscopic Database in 2006. We linked colonoscopy records for these patients to Medicare colonoscopy claims by using patient age, sex, date of procedure, and performing provider's Unique Physician Identification Number. MAIN OUTCOME MEASUREMENTS: Sensitivity, specificity, positive and negative predictive values of the Medicare claims for potential quality measures, including colonoscopy findings and procedures.
RESULTS: We linked Medicare colonoscopy claims to 15,168 of the 30,011 Clinical Outcomes Research Initiative colonoscopy records. Sensitivity of the claims for colon polyps was 93.4%, with a specificity of 97.8%. Sensitivity of claims for other diagnoses, including colorectal tumors was suboptimal, although specificity was high. In contrast, sensitivity of claims for procedures-biopsy (with or without cautery) or polypectomy-was high (87.2%-97.6%), with specificity >97%. Claims had poor sensitivity for identification of incomplete colonoscopy. LIMITATIONS: Potential for inaccurate matching of colonoscopy records and Medicare claims.
CONCLUSIONS: Medicare claims have high sensitivity and specificity for polyp detection, biopsy, and polypectomy at colonoscopy, but sensitivity is low for other diagnoses such as tumor detection and for incomplete colonoscopy. Caution is needed when using Medicare claims data for certain important quality measures, in particular tumor detection and incomplete colonoscopy.