Severe bleeding events in adults and children with primary immune thrombocytopenia: a systematic review

Summary Background The burden of severe bleeding in adults and children with immune thrombocytopenia (ITP) has not been established. Objectives To describe the frequency and severity of bleeding events in patients with ITP, and the methods used to measure bleeding in ITP studies. Patients/Methods We performed a systematic review of all prospective ITP studies that enrolled 20 or more patients. Two reviewers searched Medline, Embase, CINAHL and the Cochrane registry up to May 2014. Overall weighted proportions were estimated using a random effects model. Measurement properties of bleeding assessment tools were evaluated. Results We identified 118 studies that reported bleeding (n = 10 908 patients). Weighted proportions for intracerebral hemorrhage (ICH) were 1.4% for adults (95% confidence interval [CI], 0.9–2.1%) and 0.4% for children (95% CI, 0.2–0.7%; P