Subarachnoid hemorrhage in an isolated population. Incidence on the Faroes during the period 1962-1975.

In a retrospective study of a 14-year period (1962-1975) the annual incidence of subarachnoid hemorrhage (SAH) was found to be 7.4 per 100,000 in an isolated population of about 40,000. The age-specific incidences in the age groups from 15-25 to 60 years are on the same level as found in Sweden, Rochester USA, England, and Iceland, but lower than the findings in Finland. The age-specific incidence among persons over 60 years of age was far lower than in Sweden, Rochester USA, and Finland. The possible causes of the lower incidence in all age groups than reported in the above-mentioned studies are discussed. Forty patients had a history of SAH. Two months after the episode 38% had died and at the end of 5 years 53%. The recurrence rate at 5 years was 24%.