Abstract
IMPORTANCE: Benzodiazepines, which are associated with safety-related harms for older adults, were not covered when the US Medicare Part D prescription drug benefit began. Coverage was extended to benzodiazepines in 2013. OBJECTIVE: To examine whether the expansion of benzodiazepine coverage among Medicare Advantage (MA) beneficiaries was associated with increases in fall-related injuries or overdoses among older adults. DESIGN, SETTING, AND PARTICIPANTS: This ecological study used interrupted time-series with comparison-series analyses of MA claims data from 4 635 312 age-eligible MA beneficiaries and 940 629 commercially insured individuals (comparison group) stratified by age (65-69, 70-74, 75-79, and ≥80 years) to separately compare trends in fall-related injury and overdose before (January 1, 2010, to December 31, 2012) and after (January 1, 2013, to December 31, 2015) coverage expansion for benzodiazepines. Data analysis was performed from September 1, 2018, to August 31, 2019. EXPOSURES: Expansion of benzodiazepine coverage in Medicare Part D in 2013. MAIN OUTCOMES AND MEASURES: Monthly rate of fall-related injury and overdose. RESULTS: In 2012 (the year before the policy change), women constituted 57.5% of the MA group and 47.4% of the comparison group. A total of 25.8% of individuals in the MA group were aged 65 to 69 years, and 29.3% were 80 years or older (mean [SD], 75.1 [6.4] years); 56.7% of individuals in the comparison group were aged 65 to 69 years, and 15.1% were 80 years or older (mean [SD] age, 70.9 [6.5] years). In the MA group, 4 635 312 individuals contributed 156 754 749 person-months from 2010 through 2015; in the comparison group, 940 629 individuals contributed 25 104 534 person-months. After coverage of benzodiazepines began, the rate (ie, slope) of fall-related injury among MA beneficiaries increased from before to after coverage among all age groups. Compared with the comparison group, the increase in rate was statistically significant for those 80 years or older (rate changes for the MA vs comparison groups: 0.12 [95% CI, 0.07 to 0.17] vs -0.01 [95% CI, -0.11 to 0.10]; P = .04 for interaction). The overdose trend changed from decreasing to increasing among MA beneficiaries after coverage for all age groups, with a statistically significant increase compared with the comparison group among those aged 65 to 69 years (rate changes for the MA vs comparison groups: 0.23 [95% CI, 0.17 to 0.30] vs 0.02 [95% CI, -0.06 to 0.11]; P < .001 for interaction) and among those 80 years or older (rate changes for the MA vs comparison groups: 0.07 [95% CI, 0.00 to 0.14] vs -0.20 [95% CI, -0.35 to -0.05]; P = .002 for interaction). Results among MA beneficiaries were consistent when stratified by sex and when limited to those prescribed opioids. CONCLUSIONS AND RELEVANCE: Medicare's expansion of benzodiazepine coverage may have been associated with increases in the rates of overdose among adults ages 65 to 69 years and in the rates of overdose and fall-related injury among those 80 years or older.