OUTCOMES AND IMPACT OF COVID-19 ON INFECTION DIAGNOSIS RATES AMONG PATIENTS WITH PRIMARY IMMUNODEFICIENCY DISEASES

INTRODUCTION: We compared healthcare resource utilization (HCRU) among patients with primary immunodeficiency diseases (PIDD) in the United States before and after treatment initiation with immunoglobulin replacement therapy. Impact of COVID-19 mitigation efforts on infection diagnosis rates was evaluated. METHODS: De-identified patients with PIDD who newly initiated treatment with immune globulin infusion (human), 10% (IG10%) during July 1, 2012–August 31, 2019 (main study) were selected from IBM® MarketScan® Databases using diagnosis and prescription codes (exempt from IRB review). Patients were followed for 6 months before (preindex) and after (postindex) their first IG10% claim date. Demographic characteristics were described; pre- and postindex treatment characteristics and HCRU were compared. Infection diagnosis rates during COVID-19 (March 1, 2020–December 31, 2020) and before COVID-19 (March 1, 2019–December 31, 2019) were compared. RESULTS: The main study included 1497 patients (mean age 43 years, 67% women) who frequently had PIDD-related comorbidities like asthma (32%). Diagnoses of severe infections decreased after IG10% initiation (20% vs 12%). Infection-related post-index decreases (P<0.001) were observed for inpatient admissions (20% vs 11%) and outpatient services (80% vs 72%). Fewer patients with PIDD were diagnosed with infections during COVID-19 than before COVID-19 (23% vs 31%). CONCLUSION: Treatment with IG10% reduced severe infections and lowered infection-related HCRU by shifting care from inpatient to outpatient settings. As infection rates often differ seasonally, the 0.7-fold decrease in infection diagnoses during March–December 2020 relative to March–December 2019 suggests a reduction in infections among patients with PIDD during COVID-19, possibly due to isolation and/or decreased reporting to physicians.