Supplemental Oxygen Use, Outcomes, and Spending in Patients With COPD in the Medicare Competitive Bidding Program.

Importance: The Medicare Competitive Bidding Program (CBP), a policy that reduced durable medical equipment prices, was implemented starting in 2011. Legislation introduced in 2024 aims to remove supplemental oxygen from the CBP because of concerns that recent decreases in oxygen prescribing are due to lower prices set by the CBP, which may have decreased supply and, in turn, limited oxygen access for patients with chronic lung diseases. However, low-value prescribing of oxygen is also prevalent in practice, and decreased oxygen prescription rates may not have necessarily caused harm. Little is known about the association of the CBP with patient use, outcomes, or spending.

Objective: To examine the association between the 2011 and 2013 implementation of the CBP and supplemental oxygen use, clinical outcomes, and supplemental oxygen spending among patients with chronic obstructive pulmonary disease (COPD).

Design, setting, and participants: This cohort study used a difference-in-differences (DID) method to evaluate the association between implementation of the CBP and the outcomes of interest. Patients aged 65 to 100 years with COPD living in CBP areas were compared with those living in areas where the CBP was not yet or never implemented. The study included 100% fee-for-service Medicare data of beneficiaries enrolled between July 1, 2009, and December 31, 2015. The data analysis was performed between June 6, 2023, and August 16, 2024.

Exposure: The 2011 and 2013 implementation cycles of the Medicare CBP.

Main outcomes and measures: The primary outcomes were new prescriptions of oxygen during a 6-month period among beneficiaries with COPD and discontinuation of oxygen during a 6-month period among beneficiaries with COPD previously prescribed oxygen. Secondary outcomes included switches between oxygen types (gas, liquid, or concentrator), all-cause mortality, all-cause unplanned hospitalizations, COPD hospitalizations, and mean monthly allowed charges (total spending) over a 6-month period. The analysis was performed using the Callaway-Sant'Anna method, a dynamic DID model for policies with staggered implementation.

Results: Among 5 753 308 Medicare beneficiaries with COPD (mean [SD] age, 79.2 [8.4] years; 55.1% female), 25.9% received supplemental oxygen for at least one 6-month period during the study. The CBP was not associated with differential changes in new oxygen prescribing (DID estimate, -0.19 percentage points; 95% CI, -2.45 to 2.08 percentage points) or oxygen discontinuations (DID estimate, -0.77 percentage points; 95% CI, -8.15 to 6.60 percentage points). Similarly, differential changes were not observed in the secondary outcomes of oxygen switches (DID estimate, -0.04 percentage points; 95% CI, -0.44 to 0.37 percentage points), all-cause mortality (DID estimate, 0.16 percentage points; 95% CI, -7.52 to 7.84 percentage points), all-cause unplanned hospitalizations (DID estimate, -0.20 percentage points; 95% CI, -10.94 to 10.53 percentage points), or COPD hospitalizations (DID estimate, -0.04 percentage points; 95% CI, -2.57 to 2.48 percentage points). Differential changes were observed for mean monthly allowed charges (DID estimate, -$326.22; 95% CI, -$434.76 to -$217.68).

Conclusions and relevance: In this study, among beneficiaries with COPD, the Medicare CBP was associated with differentially lower spending but not differential changes in oxygen use or clinical outcomes. This study did not find evidence supporting ongoing policy efforts to remove supplemental oxygen from the CBP.