Two people with the same lung function, the same symptoms, and the same physician can leave with different COPD inhalers. Often the difference is not clinical. It is which plan they carry.
Insurance formularies determine which inhalers are covered, at what tier, and under what conditions. A cross-sectional analysis published in the American Journal of Managed Care examined all 689 standalone Medicare prescription drug plans and 2,578 Medicare Advantage drug plans offered in 2017 and found meaningful variation in how they applied coinsurance, prior authorization, and step therapy across six inhaler categories recommended by international COPD guidelines. That study, from Johns Hopkins researchers, was published in 2021, so its plan-level figures describe an earlier market rather than today's.
