Medicare beneficiaries' knowledge of Part D prescription drug program benefits and responses to drug costs.

CONTEXT Medicare Part D drug benefits include substantial cost sharing. OBJECTIVE To determine beneficiaries' knowledge of benefits and cost responses. DESIGN, SETTING, AND PARTICIPANTS Telephone interviews were conducted in 2007 in a stratified random sample of community-dwelling Kaiser Permanente-Northern California Medicare Advantage beneficiaries aged 65 years or older, with a gap in coverage if they exceeded $2250 in drug costs (N = 1040; 74.9% response rate). Half were selected to have reached the gap in 2006. In the source population of Medicare Advantage Prescription Drug plan beneficiaries, 8% entered the coverage gap in 2006. Models were adjusted for individual characteristics and weighted for sampling proportions. MAIN OUTCOME MEASURES Knowledge of cost sharing including awareness of the coverage gap, gap start and end amounts, and drug cost sharing before, during, and after the gap. Cost-related responses including cost-coping behaviors (eg, switching to lower-cost medications), reduced adherence (eg, not refilling prescriptions), and financial burden (eg, going without necessities). RESULTS An estimated 40% (95% confidence interval [CI], 35%-45%) of beneficiaries were aware that their drug plan in 2006 included a coverage gap; knowledge of the gap was greater among individuals who reached the gap during the year. Approximately 36% (95% CI, 32%-41%) of beneficiaries reported at least 1 of the following responses to drug costs: cost-coping behavior (26%), reduced adherence (15%), or experiencing financial burden (7%). In multivariate analyses, beneficiaries with lower household income more frequently reported cost responses (difference of 14.5 percentage points for < $40,000/y vs > or = $40,000/y [95% CI, 3.6-25.4 percentage points]). Compared with beneficiaries who were unaware of having a coverage gap, those who were aware more frequently reported any cost response (difference of 11.3 percentage points [95% CI, 0.8-21.9 percentage points]), but had fewer reports of borrowing money or going without necessities (difference of 5.5 percentage points [95% CI, 1.1-10.0 percentage points]). CONCLUSIONS Beneficiaries in this Medicare Advantage plan have limited knowledge of Part D cost sharing and often report behavioral responses to drug costs. Limited knowledge is associated with fewer reports of cost responses overall, but more reports of financial burden.