Duffy Testing to Benefit Children's Population Health: A Cost-Effectiveness Analysis

Area of Science:

• Medical Genetics
• Clinical Diagnostics
• Health Economics

Background:

• The Duffy null phenotype affects ~10% of Americans, leading to naturally lower absolute neutrophil counts (ANC).
• Misinterpreting these normal low ANC values can trigger unnecessary diagnostic testing and referrals for neutropenia workups.
• Current diagnostic practices may not account for Duffy null phenotype prevalence, impacting cost-effectiveness.

Purpose of the Study:

• To evaluate the economic value of routine serologic Duffy testing versus no testing in infants (9-12 months).
• To determine if Duffy testing is a cost-effective strategy to prevent unnecessary neutropenia workups.
• To analyze the impact of Duffy testing on healthcare costs from a US societal perspective.

Main Methods:

• A Markov cohort model was employed to simulate lifetime costs and outcomes.
• Analyses incorporated various diagnostic workup strategies for neutropenia.
• Economic value was assessed using incremental net monetary benefit (iNMB) per quality-adjusted life-year (QALY) at accepted willingness-to-pay thresholds.

Main Results:

• Serologic Duffy testing was consistently favored across base-case and sensitivity analyses, showing a positive iNMB ($2.18-$92.77 per child).
• The cost of Duffy testing, neutropenia workup costs, and low ANC prevalence significantly influenced iNMB.
• Probabilistic analyses indicated universal Duffy testing was cost-effective in most scenarios, with favorable thresholds aligning with prevalence in at least 20 US states.

Conclusions:

• Routine serologic Duffy testing is a cost-effective strategy for infants in the US.
• Implementing Duffy testing can reduce unnecessary diagnostic evaluations and associated healthcare expenditures.
• Universal or targeted Duffy testing aligns with cost-effectiveness at relevant prevalence thresholds, optimizing resource allocation.