Observational studies of any dose of antiplatelet or anticoagulant medicines with follow-up that extended beyond discharge in adult patients with radiologically confirmed intracranial haemorrhage were eligible for inclusion. The primary outcome was recurrent intracranial haemorrhage. Secondary endpoints were serious thrombo-occlusive events. Case studies were excluded.
The included cohort and case series evaluated antiplatelet therapy and oral anticoagulants in patients with prosthetic heart valve, atrial fibrillation, ischaemic stroke, transient ischaemic stroke, myocardial infarction, peripheral vascular disease and ischaemic heart disease. The control groups in cohort studies were non-users. The mean age of patients ranged from 11 to 82 years.
The authors did not state how many reviewers performed study selection.