Disparities in Monoclonal Antibody (mAb) Treatment Usage in the Military Health System During the COVID-19 Pandemic

Monoclonal antibodies (mAbs) were identified in 2020 as potential curative agents for COVID-19, particularly in high-risk populations. However, studies report differences in receipt of mAbs by race, sex, and insurance status. We hypothesized that Military Health System (MHS) beneficiaries, who are universally insured, would have approximately equal uptake of mAbs across sociodemographic categories.

Beneficiaries (active-duty service members, dependents, retirees) aged 12-64, receiving a COVID-19 diagnosis and outpatient treatment between November 9, 2020, and January 24, 2022, were identified from claims data in the MHS Data Repository (MDR). Analyses comprised descriptive statistics on demographics and frequency of COVID-19 mAb treatment for all eligible beneficiaries and by sex, race, sponsor rank, and risk status. Unadjusted and adjusted odds ratios (OR) for likelihood of receiving mAb treatment were obtained using multivariable logistic regression models for all beneficiaries as well as only those classified as "high risk."

Of 221,036 COVID-19 patients receiving outpatient care, 9907 (4.5%) received mAb treatment. Beneficiaries who received treatment were predominately White (53%), female (57%), ages 45-64 (64%), dependents (56%), associated with enlisted rank (77%), and not at high risk of developing severe COVID-19 and/or hospitalization (86%). Greater uptake of mAbs by American Indian/Alaska Native and lesser uptake by Black and Asian compared to White patients, and by female compared to male patients, concurs with published results in the greater US population.

Despite universal insurance, significant differences were observed in receipt of mAbs by race, rank (proxy for socioeconomic status), and sex. These results suggest that factors beyond insurance play roles in determining who receives mAbs. The provision of mAbs to non-high-risk patients also suggests a role for either patient- or provider-induced demand. Further research is needed to determine the scope of factors affecting mAb uptake in the MHS, and in other large health systems.