Medicare Part D coverage gap reduces antidepressant use in the elderly

Research Activities, December 2012, No. 388

The Medicare Part D prescription drug benefit includes a $265 deductible, an insured period during which the beneficiary pays 25 percent of drug costs from $265 to $2,400, and a coverage gap when the beneficiary pays 100 percent of drug costs until reaching the catastrophic limit of $3,850; then they pay 5 percent. A new study found that elderly Medicare patients with depression enrolled in standalone Part D plans in 2007 reduced their use of antidepressants during the Medicare Part D coverage gap. In fact, a full gap in drug coverage resulted in a 12.1 percent reduction in antidepressant use, particularly for brand-name drugs.

The researchers studied 65,223 Medicare beneficiaries 65 years or older with depression. They looked at three groups: no coverage before and after the coverage gap threshold, generic-only coverage, and those with low-income subsidies. They analyzed medication use patterns, including the average number of monthly prescriptions filled per month. As drug coverage improved, people with depression were more likely to spend up to their coverage-gap threshold. Among the groups, 43.1 percent with no-coverage, 69.2 percent in the generic-only group, and 72.2 percent with LIS reached this threshold.

The average length of time spent in the gap was 115 days, 137 days, and 128 days, respectively. A gap in coverage was associated with a significant reduction in antidepressant use per month in the no-coverage (12.1 percent) and the generic-only group (6.9 percent). The majority of these reductions were for brand-name drugs. There were also reductions in the use of heart failure drugs (12.9 percent) and oral anti-diabetes medications (13.4 percent). Despite the reduction in antidepressant use, there was no associated increase in non-drug medical spending. The study was supported in part by the Agency for Healthcare Research and Quality (HS18657).

See "Effects of Medicare Part D coverage gap on medication and medical treatment among elderly beneficiaries with depression," by Yuting Zhang, Ph.D., Seo Hyon Baik, Ph.D., Lei Zhou, M.S., Charles F. Reynolds, M.D., and Judith Lave, Ph.D., in the July 2012 Archives of General Psychiatry 69(7), pp. 672-679.


Current as of December 2012
Internet Citation: Medicare Part D coverage gap reduces antidepressant use in the elderly: Research Activities, December 2012, No. 388. December 2012. Agency for Healthcare Research and Quality, Rockville, MD.