Similarities and differences in aneurysmal subarachnoid haemorrhage between eastern Finland and northern Sydney.

A significant body of literature on aneurysmal subarachnoid haemorrhage has emerged from Finland. The Finnish source from a small founding population, rather than from a wide heterogeneous source such as used for other populations, suggests the need for caution when attempting to generalise using Finnish data. This study aims to identify the differences and similarities between the aneurysmal subarachnoid haemorrhage populations of eastern Finland and northern Sydney to ascertain whether information that is derived from Finland has applicability to an Australian context. Existing aneurysmal subarachnoid haemorrhage databases of Kuopio University Hospital in eastern Finland and the Royal North Shore and Dalcross Private Hospitals in northern Sydney from 2000 to 2005 were combined and analysed. A total of 879 patients were identified. Comparisons fell into three categories: features that were similar between the two populations; those with apparent differences that may be explained by methods of data collection or referral patterns; and differences that probably represent a true difference between these populations. The differences suggest that genetic predispositions for aneurysm development may not affect the likelihood for aneurysmal rupture.