DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional and longitudinal analyses of surveys of a probability sample of Medicare beneficiaries in 13 states in 1998 and 2000.

MAIN OUTCOME MEASURE: Self-reported rates of skipping medications and other treatments.

RESULTS: Cost-related skipping rates increased from 9.5% in 1998 to 13.1% in 2000. In separate multivariable models using 1998 and 2000 data, higher out-of-pocket costs, lower physician-patient relationship quality, low income, and lacking prescription drug coverage were associated with more skipping (P<.05 for all). Better physical and mental health, and greater age were associated with less skipping (P<.05). HMO membership was not associated with higher rates of skipping in 1998 (P=.84), but was in 2000 (P<.0004). In longitudinal analyses, increased medication costs and HMO membership were associated with the observed increase cost-related skipping between 1998 and 2000.

CONCLUSIONS: Cost-related skipping was associated with several factors, including drug coverage, poverty, poor health, and physician-patient relationship quality. The important role of physician-patient relationships in cost-related skipping has not been shown previously. Physicians should be aware of these risk factors for cost-related skipping, and initiate dialogue about problems paying for prescription medications and other treatments.