Epidemiology of Intracerebral Haemorrhage

Intracerebral haemorrhage (ICH) has an overall incidence of 24.6 per 100,000 person-years and is associated with a high case fatality. Understanding the risk factors for ICH occurrence informs primary prevention strategies. This article provides an update on the current global patterns of ICH incidence and the common and emerging risk factors associated with ICH.

We searched Ovid Medline (from 1980 to Oct 2014) for systematic reviews that addressed the epidemiology of ICH and for recent original studies that revealed new insights into the frequency of and the risk factors associated with ICH.

The incidence of ICH has not changed over the last 30 years, and this consistency is thought to be due to changes in the risk factor profiles of ICH patients. It appears that ICH is more common in men and during the winter months. ICH affects Asian populations more frequently than other populations. In addition to the known risk factors of hypertension and increasing age, alcohol consumption, the presence of the apolipoprotein ε2 or ε4 allele, extremes of body mass index, diabetes, and ophthalmic conditions have been suggested to be associated with ICH. Factors associated with a reduced risk of ICH include hypercholesterolaemia and a diet high in fruits and vegetables.

The overall incidence of ICH has remained unchanged, but its regional incidence varies by race, sex, season and geographical location. In high income countries, the beneficial effect of improving blood pressure control may be counterbalanced by the increased use of antithrombotic drugs. Emerging modifiable risk factors include alcohol consumption, body mass index, diabetes, and fruit and vegetable intake, all of which may be amenable to interventions for the primary prevention of ICH (as well as many other diseases).