Trends in colorectal cancer test use in the medicare population, 1998-2005.

BACKGROUND: Colorectal cancer (CRC) screening has been covered under the Medicare program since 1998. No prior study has addressed the question of the completeness of CRC screening in the entire Medicare cohort.
METHODS: In 2008, CRC test-use rates were analyzed for the national fee-for-service Medicare population using Medicare enrollment and claims data from 1998 through 2005. Annual test-use rates were calculated for fecal occult blood testing, sigmoidoscopy, barium enema, and colonoscopy for each year by the demographic characteristics of enrollees. A current-in-Medicare rate was calculated to assess the percentage of enrollees with CRC testing according to recommended intervals.
RESULTS: Colonoscopy rates have increased every year since the introduction of CRC screening coverage. Test-use rates for all other test modalities have steadily decreased. The percentage of Medicare enrollees receiving appropriate tests has slowly increased. In 2005, 47% of enrollees aged >or=65 years and 33% of enrollees aged 50-64 years had claims indicating that they had been tested according to recommended intervals.
CONCLUSIONS: CRC test-use rates in the Medicare population are low. Disparities are apparent by age, race/ethnicity, gender, disability, income, and geographic residence. Much work remains to be done to increase testing to acceptable levels.