Figure 2. Monthly Rates of Overdose Among Medicare Advantage and Commercially Insured Enrollees From 2010 to 2015.

In models that included fixed effects for month, the interaction term that compared the Medicare Advantage and comparison group rate changes was statistically significant for those aged 65 to 69 years (P < .001) and those 80 years or older (P = .002) and not significant for those age 70 to 74 years (P = .33) or 75 to 79 years old (P = .49). Full results are given in Table 3. The vertical dashed line indicates the time of Medicare Part D benzodiazepine coverage expansion.