Financial Burdens of Out-of-Pocket Spending Among Medicare Fee-for-Service Beneficiaries: Role of the "Big Four" Chronic Health Conditions.

While Medicare is the universal source of health care coverage for Americans aged 65 years or older, the program requires significant cost sharing in terms of out-of-pocket (OOP) spending. We conducted a retrospective study using data from 2016 to 2018 Medicare Current Beneficiary Surveys of elderly community-dwelling beneficiaries ( = 10,431) linked with administrative data to estimate OOP spending associated with the "big four" chronic diseases (cardiovascular disease, cancer, diabetes, and chronic lung disease). We estimated a generalized linear model adjusting for predisposing, enabling, and need factors to estimate annual OOP spending. We found that beneficiaries with any of the "big four" chronic conditions spent 15% ( < .001) higher OOP costs and were 56% more likely to spend ≥20% of annual income on OOP expenditure (adjusted odds ratio = 1.56; < .001) compared with those without any of those conditions. OOP spending appears to be heterogeneous across disease types and changing by conditions over time.