Incidence, case fatality, and functional outcome of intracerebral haemorrhage, according to age, sex, and country income level: a systematic review and meta-analysis.

Background: Intracerebral haemorrhage (ICH) accounts for approximately 28% of all strokes worldwide. ICH has a high case fatality, and only few survivors recover to independent living. Over the past decades, demographic changes, and changes in prevalence and management of risk factors may have influenced incidence. Widespread implementation of stroke units and improved care in general may have affected case fatality and outcome. We aimed to update the evidence on incidence, case fatality, and functional outcome of ICH, according to age, sex, and country income level.

Methods: We systematically searched PubMed and Embase from 2008 to April 2023 for prospective population-based studies on incidence, case fatality, or functional outcome of first-ever ICH. We excluded studies in which less than 80% of cases was confirmed with imaging or autopsy. Quality of the studies was assessed based on the used case finding methods. We used inverse variance-based random-effects meta-analyses to pool the crude incidence, case fatality at 1 month, and the percentage of patients with good functional outcome after 3, 6, or 12 months, as defined by the authors of the individual studies. Time trends were assessed using weighted linear meta-regression. Funnel plots were constructed to study publication bias. The review was registered on PROSPERO (CRD42023413314).

Findings: We identified 70 eligible studies, describing 19,470 ICH patients from 26 different countries. Of these, 62 studies reported on crude incidence, 41 on case fatality, and 10 on functional outcome. Overall crude incidence was 29.2 per 100,000 person-years (95% CI 23.3-36.4; I = 100%). Incidence was lower in women than in men and increased with age. Incidence was highest in lower-middle income countries, followed by high and upper-middle income countries. Case fatality at 1 month was 35.5% (95% CI 32.3-38.9; I = 90%). The percentage of patients with good functional outcome (mRS 0-2 in nine studies, mRS 0-3 in one) after 3-12 months was 31.2% (95% CI 24.7-38.6; I = 76%). We found no time trends in incidence, case fatality, or functional outcome.

Interpretation: Our results demonstrate the persistently high burden and devastating consequences of ICH, stressing the need for better preventive strategies and acute treatments.

Funding: None.