Screening mammography was used more, and more frequently, by longer than shorter term Medicaid enrollees.

OBJECTIVE: Recent studies have shown that timing and length of enrollment (LOE) in Medicaid in relation to cancer diagnosis are associated with stage of breast cancer among Medicaid beneficiaries. Whether LOE in Medicaid is also associated with the use of screening mammography (USM) is unclear, however. The objective was to determine whether USM among Medicaid beneficiaries is associated with LOE in Medicaid. STUDY DESIGN AND
SETTING: The study used Ohio Medicaid enrollment and claims files, and a cohort approach to estimate USM during the 8-year study period. USM was assessed through (a) the proportion of women receiving screening mammography, and (b) the frequency of screening mammography exams. This study used women 40-64 years of age enrolled in Ohio Medicaid during 1992-1999 (n=140,592).
RESULTS: The proportion of women receiving screening mammography increased significantly with each additional year of LOE [adjusted odds ratio (AOR): 1.59, 95% confidence interval (95% CI): 1.57-1.60], and was higher among women presenting comorbid conditions (AOR: 3.05; 95% CI: 2.90-3.20). The mean number of annual mammography exams increased from 0.08 among women with LOE < or = 12 months, to 0.26 among women with LOE > or = 7 years.
CONCLUSION: Both LOE and comorbid conditions are independently, significantly, and positively associated with USM, although their interactive effect relative to USM needs to be studied further. These findings have important implications in the methods employed to study use of cancer screening and other preventive services by Medicaid beneficiaries, as well as in Medicaid policy analysis and program management.