Real-world Retrospective Analysis of Patient Characteristics, Healthcare Resource Utilization, Costs, and Treatment Patterns among Unvaccinated Adults with COVID-19 Diagnosed in Outpatient Settings in the United States.

Aims This retrospective analysis of the Optum Clinformatics Data Mart database evaluated US patient characteristics, healthcare resource utilization (HCRU), costs, and treatment patterns among unvaccinated adults with outpatient-diagnosed COVID-19 to quantify US economic burden. Materials and methods The index event was the earliest outpatient diagnosis of confirmed COVID-19 from May 1 to December 10, 2020. Patients had 12 months' continuous enrollment before and were followed for >= 60 days after index date until insurance dis-enrollment or study end. Results 236,589 patients had outpatient-diagnosed COVID-19 (7,692 with and 228,897 without subsequent COVID-19-related inpatient admission >48 h post-diagnosis). The median age was 51 years (>= 65 years, 30.0%); 72.4% had >= 1 risk factor. Patients with versus without subsequent inpatient admission were more often male, older, Black/Hispanic, and had comorbidities/risk factors. With a median follow-up of 162 days, patients had a median of 1 COVID-19-related outpatient visit (with inpatient admission, 5 outpatient visits). Those with inpatient admission had a median of 1 COVID-19-related inpatient visit (median length of stay [LOS], 6 days), 33.3% were admitted to intensive care (median LOS, 8 days), 8.4%, 7.1%, and 13.3% received invasive mechanical ventilation, noninvasive mechanical ventilation, and supplemental oxygen, respectively; 13.5% experienced readmission. Inpatient mortality was 6.0% (0.3% for nonhospitalized patients). Antithrombotic therapy, antibiotics, corticosteroids, and remdesivir use increased among patients with inpatient admission versus without. Median total COVID-19-related non-zero medical costs were $208 for patients without inpatient admission (with inpatient admission, $39,187). Limitations Results reflect the circulating SARS-CoV-2 and treatment landscape during the study period. Requirements for continuous enrollment could have biased the population. Cost measurements may have included allowed (typically higher) and charge amounts. Conclusions Given the numbers of the US population who are still not fully vaccinated and the evolving epidemiology of the pandemic, this study provides relevant insights on real-world treatment patterns, HCRU, and the cost burden of outpatient-diagnosed COVID-19.