Coagulation Testing Practices and Guideline Adherence in Hemophilia A: A Retrospective Quality Assessment of a Dutch Expertise Hemophilia Treatment Center

BACKGROUND: Coagulation testing in persons with hemophilia A (PwHA) is required for diagnosis, monitoring replacement therapy, assessment of adherence, and detection of inhibitors. However, data on testing practices are limited, and alignment with guideline recommendations is unclear. OBJECTIVES: To describe longitudinal coagulation testing practices in adult PwHA, assess guideline adherence, and explore the clinical consequences of current testing practices. METHODS: Coagulation testing of adult PwHA of all severities treated at a single Dutch hemophilia treatment center between 2014-2025 were retrospectively analyzed. Patient characteristics, coagulation assays, FVIII exposure, and interventions were pseudonymously extracted from patient records. RESULTS: Persons with severe (n = 31), moderate (n = 31), and mild (n = 131) hemophilia A were included. Median annual testing rate increased from 0.6 [IQR 0.3-1.0] in mild PwHA to 2.3 [IQR 1.7-3.3] in severe PwHA. The annual testing rate decreased from 1.7 [IQR 1.4-2.0] pre-2020 to 0.7 [IQR 0.7-0.7] from 2020 onwards. Adherence was low across three guidelines (adherence 1%-38%). The most common clinical consequences of testing were emicizumab dose adjustments in 7/27 (26%) emicizumab-treated PwHA and detection of periinterventional below-target FVIII levels immediately post-intervention (19/49, 37%) or within the first two postoperative days (46/136, 34%). Bleeding complications occurred in 13% of interventions with below-target FVIII levels versus 5% with levels within target. CONCLUSIONS: Coagulation testing rates in PwHA declined over time and guideline adherence was low. Further discussion on improved monitoring strategies and guidelines is warranted, particularly considering the major changes in hemophilia treatment over the past decade.