Diagnostic utility of the ISTH bleeding assessment tool in patients with suspected platelet function disorders

ESSENTIALS: The utility of bleeding assessment tools regarding platelet function disorders is still elusive. We studied consecutive patients in a prospective cohort study in a tertiary hospital. Substantially higher scorings were observed in patients with platelet function disorders. Bleeding assessment tools might provide a useful screening tool. BACKGROUND: Bleeding assessment tools (BATs) have been widely implemented in the evaluation of patients with suspected bleeding disorders. However, diagnostic BAT utility regarding platelet function disorders is still elusive. AIM: We aimed to assess the diagnostic value of the International Society on Thrombosis and Haemostasis BAT (ISTH‐BAT) for platelet function disorders in clinical practice. METHODS: The clinical characteristics and laboratory data of all consecutive patients with a suspected bleeding disorder referred between January 2012 and March 2017 to an outpatient unit of a university hospital were prospectively collected. The diagnostic evaluation was performed according to current recommendations following a prespecified protocol and platelet function was tested using light transmission aggregometry as well as flow cytometry. RESULTS: Five hundred and fifty‐five patients were assessed; 66.9% were female, median age was 43.7 years (interquartile range [IQR] 29.3, 61.7). Confirmed platelet function disorder was diagnosed in 54 patients (9.7%), possible platelet function disorder in 64 patients (11.5%), and other disorders in 170 patients (30.6%). Median scoring of the ISTH‐BAT was 2 in patients without a bleeding disorder (IQR 1, 3), 4 in patients with a possible platelet function disorder (2, 7), and 7 in patients with confirmed platelet function disorder (5, 9). Area under the receiver operating characteristic curve (the area under the curve [AUC]) was 0.75 (95% CI 0.70, 0.80). CONCLUSIONS: Presence of a platelet function disorder was associated with substantially higher BAT scorings compared to patients without. Our data suggest that the ISTH‐BAT provides a useful screening tool for patients with suspected platelet function disorders.