Greater COVID-19-related healthcare utilisation with multimorbidity versus single or immunocompromised conditions

<bold>Introduction:</bold> The impact of multimorbidity (≥2 chronic conditions) on risk of severe COVID-19 outcomes and healthcare resource utilisation (HCRU) is unknown. We compared COVID-19-related HCRU among individuals with multimorbidity to those with immunocompromising (IC) conditions and those with single high-risk conditions. <bold>Methods:</bold> We conducted a retrospective study using Optum's de-identified Clinformatics^® Data Mart Database and applying US Centers for Disease Control and Prevention criteria for COVID-19 high-risk conditions in 2 time periods: BA/BQ and XBB. The first day of the variant-defined period was the index date. Adults ≥18 years with IC conditions at index were compared to adults with chronic heart disease (CHD), diabetes (DBT), obesity, and hypertension (HTN). COVID-19-related HCRU within 90 days following index included hospitalisation, emergency room or urgent care visits, and outpatient visits. <bold>Results:</bold> Multimorbidity affected ~3-7 times more individuals than IC and single conditions (Figure). Adults with multimorbidity generally also had greater inpatient and outpatient HCRU than individuals with IC or a single condition, in both age groups, except outpatient visits in younger adults. <bold>Conclusions:</bold> Adults with multimorbidity had greater COVID-19 HCRU, especially if aged ≥65. Identifying populations with multiple chronic comorbidities can inform COVID-19 vaccination and treatment guidelines. <fig><object-id>erj;64/suppl_68/PA1522/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>