Chromogenic vs one-stage assay to diagnose women and girls with hemophilia A-mapping global approaches and assessing challenges: communication from the SSCs of the ISTH

Abstract

Background: Assay discrepancies are well recognized in diagnosing men and boys with hemophilia A (MBwHA), but are not well studied in women and girls with hemophilia A (WGwHA).

Objectives: To survey hemophilia providers to map global approaches/perspectives/challenges in diagnosing WGwHA with a chromogenic assay (CSA) vs one-stage assay (OSA) and other diagnostic tools to diagnose WGwHA compared with MBwHA.

Methods: The International Society on Thrombosis and Haemostasis Scientific and Standardization Committees on FVIII, FIX and Rare Coagulation Disorders and Pediatric and Neonatal Thrombosis and Haemostasis convened a working group, which compiled a Research Electronic Data Capture survey and disseminated it to global hemophilia providers. Descriptive statistics were applied to survey results.

Results: Of 174 respondents, 95% were hemophilia providers, comprising 34% adult hematologists, 58% pediatric hematologists, 2% nurse practitioners, and 0.5% nurses; 95% were providers for WGwHA and WGwHMB. The results showed that CSA with/without OSA is ordered by fewer providers in women and girls (WG, 35%) than in men and boys (MB, 61%; P < .001). OSA is ordered by more providers (62%) in WGwHA due to various assay-related reasons. Bleeding Assessment Tool and genetic testing were not used to diagnose WGwHA by 29% and 33%, respectively.

Conclusion: Based on our survey results, CSA is ordered less frequently in diagnosing WGwHA compared with MBwHA, likely due to assay-related factors including cost, availability, and insurance coverage, and possibly due to some providers not considering assay discrepancies in WGwHA. Increasing global availability and improving provider consideration of assay discrepancies in WGwHA can increase use of both assays. Improved use of assays and other diagnostic tools, such as Bleeding Assessment Tool scores, will improve effective diagnoses of WGwHA.

Keywords: assay; discrepancy; girls; hemophilia A; women.