Data sources for measuring colorectal endoscopy use among Medicare enrollees.
BACKGROUND
Estimates of colorectal cancer test use vary widely by data source. Medicare claims offer one source for monitoring test use, but their utility has not been validated. We compared ascertainment of sigmoidoscopy and colonoscopy between three data sources: self reports, Medicare claims, and medical records.


METHODS
The study population included Medicare enrollees residing in North Carolina (n = 561) who had participated in a telephone survey on colorectal cancer tests. Medicare claims were obtained for the 5 years preceding the survey (January 1, 1998 to December 31, 2002). Information about sigmoidoscopy and colonoscopy procedures conducted in physician offices were abstracted from medical records. Sensitivity, specificity, positive predictive value, negative predictive value, agreement, and kappa statistics were calculated using the medical record as the gold standard. Agreement on specific procedure type and purpose was also assessed.


RESULTS
Agreement between claim and medical record regarding whether an endoscopic procedure had been done was high (over 90%). Agreement between self report and medical record and between self report and claim was good (79% and 74%, respectively). All three data sources adequately distinguished the type of procedure done. None of the data sources showed reliable levels of agreement regarding procedure purpose (screening or diagnostic).


CONCLUSIONS
Medicare claims can provide accurate information on whether a patient has undergone colorectal endoscopy and may be more complete than physician medical records. Medicare claims cannot be used to distinguish screening from diagnostic tests. Recognizing this limitation, researchers who use Medicare claims to assess rates of colorectal testing should include both screening and diagnostic endoscopy procedures in their analyses.
Schenck
Anna P
AP
The Carolinas Center for Medical Excellence, 100 Regency Forest, Suite 200, Cary, NC 27511-8598, USA. aschenck@ncqio.sdps.org
Klabunde
Carrie N
CN
Warren
Joan L
JL
Peacock
Sharon
S
Davis
William W
WW
Hawley
Sarah T
ST
Pignone
Michael
M
Ransohoff
David F
DF
D000368:Aged; D000369:Aged, 80 and over; D003113:Colonoscopy / Q000706:statistics & numerical data*; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000453:epidemiology*; D003625:Data Collection / Q000706:statistics & numerical data*; D005260:Female; D006306:Health Surveys; D006801:Humans; D007345:Insurance Claim Review / Q000706:statistics & numerical data; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data*; D006278:Medicare / Q000706:statistics & numerical data*; D008875:Middle Aged; D009657:North Carolina; D015203:Reproducibility of Results; D012812:Sigmoidoscopy / Q000706:statistics & numerical data*; D013022:South Carolina; D014481:United States; D014600:Utilization Review / Q000706:statistics & numerical data