Regional differences in the incidence of aneurysmal subarachnoid haemorrhage in Finland

Abstract

We observed a relatively steady hospital-admitted incidence of aneurysmal SAH (7.41 per 100,000 person-years) in the Tampere University Hospital region. This result is parallel to a recent study looking into the incidence of aneurysmal SAH for the whole of Finland. Compared to the Tampere University Hospital region, the incidence was 64% greater in the Eastern Finland region.

Will improved neuroradiology facilities debunk the reported rarity of intracranial aneurysms in Sub-Saharan Africa?

“…A low incidence has been reported from some parts of Asia and Africa. [5,30,11,13,19,22,26,29,[31][32][33] High incidence has been reported from Japan, [8,9] Finland, [10] Greenlandic Eskimos, [15] and in Maoris of New Zealand. [18] Studies such as ours are important and needed to better understand the epidemiologic, clinical, and economic burden of cerebral aneurysms in Africa at national and regional levels.…”

“…[18] Racial differences have also been reported from Denmark, where Caucasians have a lower incidence than Eskimos, [15] from Saudi Arabia, where Arabs have lower incidence than non-Saudis [1] and from USA, where Blacks have lower incidence than Caucasians, [23] Geographical differences have been reported in Finland where regional differences exist in the incidence of aSAH. [10,27,35] Other explanations for these differences include genetic predilection and connective tissue disorders. Connective tissue defects may play a significant role in the development of IAN.…”

“…A low incidence has been reported from some parts of Asia and Africa. [ 5 , 30 , 11 , 13 , 19 , 22 , 26 , 29 , 31 - 33 ] High incidence has been reported from Japan,[ 8 , 9 ] Finland,[ 10 ] Greenlandic Eskimos,[ 15 ] and in Maoris of New Zealand. [ 18 ]…”

Author Response: Substantial Within-Country Variation in the Incidence of Subarachnoid Hemorrhage: A Nationwide Finnish Study

“…We thank Frösen et al for their interest in our study. 1 As the readers speculated, the discrepancy between the findings of their hospital-based study 2 and our registry-based study 1 is attributable to the inherent selection bias of hospital-based subarachnoid hemorrhage (SAH) studies. 3 Based on their response, we reanalyzed our data using only the data within the Tampere University Hospital catchment area and found a substantial decrease from 28% to 18% in the sudden death rate of SAH during our study period.…”

“…However, in Tampere University Hospital, one of the referral centers for the population in this article, we do not see the decreasing trend in the number of admitted aSAH cases, but rather a constant variation from 1990 to 2014. 2 The discrepancy between the data in this administrative registry-based study 1 and a study by Jalava et al based on actual observational data 2 raises the question whether the data entered to Editors' Note: Substantial Within-Country Variation in the Incidence of Subarachnoid Hemorrhage: A Nationwide Finnish Study…”