REAL-WORLD DIAGNOSTIC DELAY, TREATMENT ACCESS, AND HEALTH SYSTEM BURDEN IN PRIMARY IMMUNODEFICIENCY/INBORN ERRORS OF IMMUNITY: EVIDENCE FROM THE UNITED STATES AND EX-US SETTINGS
Author(s)
Ayan Chakraborty, M.Sc.1, Varun Ektare, MPH2, Ashmita Chatterjee, M.Sc.1, Varish Bhatia, PharmD1, Divya S. Patil, Ph.D.3, Elstin A. Raj, M.Pharm.4, Edlin G. Mathias, Ph.D.3, Tushar Pyne, Ph.D.1;
1Indence Research Private Limited, North 24 Parganas, India, 2Indence Research Private Limited, Thane West, India, 3Manipal Academy of Higher Education, Department of Health Technology and Informatics, Manipal, India, 4Manipal Academy of Higher Education, Manipal, India
1Indence Research Private Limited, North 24 Parganas, India, 2Indence Research Private Limited, Thane West, India, 3Manipal Academy of Higher Education, Department of Health Technology and Informatics, Manipal, India, 4Manipal Academy of Higher Education, Manipal, India
OBJECTIVES: Primary immunodeficiency and inborn errors of immunity (PID/IEI) lead to delayed diagnosis and high healthcare resource utilization (HCRU). This targeted literature review (TLR) descriptively compares real-world diagnostic pathways, treatment access, and utilization patterns between the United States (US) and ex-US settings.
METHODS: This PRISMA-guided TLR aimed to generate real-world evidence (RWE) on PID/IEI from PubMed and Embase (2022-2025), focusing on the US, Canada, and Europe. It included RWE on diagnostic delays, genetic testing, immunoglobulin replacement therapy (IgRT), HCRU, costs, and patient-reported outcomes in pediatric and adult populations, analyzed descriptively by geography.
RESULTS: Across 11 RWE, six were conducted in the US and five in ex-US (Europe) settings; no eligible Canadian studies were identified. Across these studies, prolonged diagnostic delays and substantial HCRU were consistently observed, though driven by different system-level factors. In the US, national claims data demonstrated a median 369-day delay from clinical suspicion to confirmed IEI diagnosis, with longer delays among older patients and those residing in socioeconomically deprived or predominantly non-White neighborhoods. Diagnostic delay was associated with delayed IgRT initiation (hazard ratio 0.64) and higher infection-related utilization. US claims analyses further showed that IgRT initiation was associated with reduced infection-related hospitalizations (10.8% post- vs 19.5% pre-initiation) and lower healthcare costs ($7,849 vs $13,995), highlighting payer-relevant efficiency signals. In ex-US studies, particularly from the UK and Europe, substantial delivery-related burden was observed, including frequent hospital attendances (median 7 visits/year), higher utilization with intravenous immunoglobulin compared with subcutaneous immunoglobulin (17 vs 6 visits/year), and meaningful patient-borne travel time and cost burden, reflecting centralized care delivery models.
CONCLUSIONS: RWE highlights persistent diagnostic delay and system burden in PID/IEI across regions, driven by payer-level inefficiencies in the US and delivery-level constraints in ex-US. Earlier diagnosis and optimized IgRT delivery offer actionable opportunities to reduce avoidable utilization, costs, and inequities.
METHODS: This PRISMA-guided TLR aimed to generate real-world evidence (RWE) on PID/IEI from PubMed and Embase (2022-2025), focusing on the US, Canada, and Europe. It included RWE on diagnostic delays, genetic testing, immunoglobulin replacement therapy (IgRT), HCRU, costs, and patient-reported outcomes in pediatric and adult populations, analyzed descriptively by geography.
RESULTS: Across 11 RWE, six were conducted in the US and five in ex-US (Europe) settings; no eligible Canadian studies were identified. Across these studies, prolonged diagnostic delays and substantial HCRU were consistently observed, though driven by different system-level factors. In the US, national claims data demonstrated a median 369-day delay from clinical suspicion to confirmed IEI diagnosis, with longer delays among older patients and those residing in socioeconomically deprived or predominantly non-White neighborhoods. Diagnostic delay was associated with delayed IgRT initiation (hazard ratio 0.64) and higher infection-related utilization. US claims analyses further showed that IgRT initiation was associated with reduced infection-related hospitalizations (10.8% post- vs 19.5% pre-initiation) and lower healthcare costs ($7,849 vs $13,995), highlighting payer-relevant efficiency signals. In ex-US studies, particularly from the UK and Europe, substantial delivery-related burden was observed, including frequent hospital attendances (median 7 visits/year), higher utilization with intravenous immunoglobulin compared with subcutaneous immunoglobulin (17 vs 6 visits/year), and meaningful patient-borne travel time and cost burden, reflecting centralized care delivery models.
CONCLUSIONS: RWE highlights persistent diagnostic delay and system burden in PID/IEI across regions, driven by payer-level inefficiencies in the US and delivery-level constraints in ex-US. Earlier diagnosis and optimized IgRT delivery offer actionable opportunities to reduce avoidable utilization, costs, and inequities.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
RWD99
Topic
Real World Data & Information Systems
Topic Subcategory
Health & Insurance Records Systems
Disease
SDC: Systemic Disorders/Conditions (Anesthesia, Auto-Immune Disorders (n.e.c.), Hematological Disorders (non-oncologic), Pain)