Adult Pharmacy Costs and Characteristics of Very High-Cost Prescription Drug Users in the United States, 2018-2022.

Abstract

Objective: This study sought to identify: (1) the demographic and clinical characteristics of very high-cost users (defined as patients with pharmaceutical expenditures that were equal to or greater than the 99th percentile), (2) whether or not these characteristics changed over time, (3) sociodemographic and clinical correlates of being very high-cost users, (4) the average pharmaceutical costs of very-high cost users, and (5) the therapeutic classes and medications that contributed to these high costs.

Background: There are growing public concerns about rising drug costs, in part due to increased availability, greater effectiveness, and market considerations. There is a concentrated portion of patients that accounts for a disproportionately large portion of pharmaceutical expenditures.

Methods: A large serial cross-sectional study was conducted with De-identified, member-level pharmacy claims (n = 65,739,791) from a large, national pharmacy benefits manager from January 1, 2018 to December 31, 2022. The main outcome and measures were 2018-2022 pharmaceutical expenditures; amounts were adjusted for inflation to reflect 2022-dollar values.

Results: Across the study period, the odds of being classified as a very high-cost user were 1.31 times as high for those 45-64 years old compared with those 18-44 years old (reference category); the odds were 1.42 times as high for males compared with females; 1.13 times as high before those identifying as non-Hispanic Black compared with non-Hispanic white; 1.11 times as high for those enrolled in a health care exchange plan compared with a commercial plan. In addition, very high-cost users lived in areas with higher social needs. Human immunodeficiency virus, inflammatory conditions, multiple sclerosis, and cancer accounted for the largest share of costs among this group.

Conclusions: This study identified the unique characteristics of very high-cost pharmaceutical users and identified the top conditions and prescription drugs that drove high pharmaceutical expenditures among this population. These findings are essential to understanding rising pharmaceutical costs in the United States and can help identify the issues and solutions of specific cost drivers within our health care policies.