Adjudicating bleeding events in a platelet dose study: impact on outcome results and challenges

BACKGROUND: In the SToP platelet dose study, the World Health Organization (WHO) bleeding grade was assigned using adjudication. This study describes the challenges associated with adjudicating bleeding events and compares the adjudicated and bedside results for bleeding grade. STUDY DESIGN AND METHODS: To categorize bleeding, the following information was provided to adjudicators: daily bleeding assessments, interventions to stop or control bleeding, daily blood counts, and transfused blood components. Each daily assessment was sent to two adjudicators who independently assigned a grade and anatomic site of bleeding. Discordant cases where disagreement occurred were sent to a third adjudicator and subsequently to a fourth or fifth adjudicator in an attempt to reach agreement. Disagreement after five adjudicators was resolved by consensus. The final adjudicated grade was compared with the grade of bleeding assigned at the bedside by study personnel. RESULTS: A total of 1150 case report forms were adjudicated. Disagreement on grade of bleeding was common: 31.2% after the first two adjudicators, 4.0% after the third adjudicator, 0.7% after four, and 0.05% after five. Disagreement on anatomic site was less but still occurred in 17% of cases after two adjudicators. The frequency of bleeding (≥ Grade 2) based on adjudication was higher than bedside grading (standard-dose arm, 47.5% vs. 34.4%; low-dose arm, 50.0% vs. 43.1%). CONCLUSION: The frequency of WHO bleeding varies depending on the method used to assign grade. Adjudication to assign bleeding grade resulted in significant disagreement when two adjudicators were used.