Variability of COPD inhaler coverage in Medicare Part D.

Stand-alone prescription drug plans (S-PDPs) and Medicare Advantage prescription drug (MA-PD) plans are incentivized to cover outpatient medications differently. This could affect the coverage of inhalers that prevent costly exacerbations of chronic obstructive pulmonary disease (COPD), with impacts for the Medicare program and its beneficiaries. This study compared the coverage of guideline-recommended COPD inhalers between S-PDPs and MA-PD plans. A cross-sectional analysis of the formularies for all 689 S-PDPs and 2578 MA-PD plans offered in 2017. We assessed each prescription drug plan's coverage of inhalers in 6 therapeutic categories recommended by the 2017 Global Initiative for Chronic Obstructive Lung Disease (GOLD) report and compared the use of prior authorization, step therapy, and coinsurance between S-PDPs and MA-PD plans. In 2017, all S-PDPs and MA-PD plans covered at least 1 inhaler from each GOLD therapeutic category, except for long-acting β agonist/long-acting muscarinic antagonist combination inhalers. S-PDPs were more likely to require coinsurance for inhalers across all therapeutic categories, whereas MA-PD plans required prior authorization more frequently for 3 of the 6 therapeutic categories. S-PDPs required coinsurance more frequently than MA-PD plans for inhalers that treat mild (20.8% vs 11.4%; P < .001), moderate (40.0 vs 13.2%; P < .001), and severe (45.4% vs 11.0%; P < .001) disease. Medicare Part D S-PDPs are more likely than MA-PD plans to require coinsurance for outpatient COPD inhalers, especially for severe disease. This likely reflects their different financial incentives and is an important consideration for providers and policy makers aiming to improve outpatient COPD management.