Has there been a decline in subarachnoid hemorrhage mortality?
We studied subarachnoid hemorrhage in the population of Rochester, Minnesota, for the 40-year period from 1945 through 1984. The average annual incidence rate of subarachnoid hemorrhage in Rochester has remained constant at approximately 11 per 100,000 population. Age-specific incidence rates increased with age. However, the average annual mortality rate for subarachnoid hemorrhage in Rochester has shown a decreasing trend, from 6.8 per 100,000 population in 1955-1964 to 4.3 in 1975-1984. It is likely that this is due to a decrease in case-fatality rates from 57% in 1945-1974 to 42% in 1975-1984 (p = 0.10). This decreasing trend was also evident in annual mortality rates from subarachnoid hemorrhage for US white men and women. The reason for the improved case-fatality rate is unclear, but it may be related to changes in management. The interval from onset of subarachnoid hemorrhage to surgery decreased from a median of 12 days in 1975-1979 to 2 days in 1980-1984, and of those who survived to receive medical attention, more patients received some form of medical treatment in 1980-1984. Whether either or both of these changes have led to the decrease in the case-fatality rate is uncertain.
Ingall
T J
TJ
Department of Neurology, Mayo Clinic, Rochester, Minnesota 55905.
Whisnant
J P
JP
Wiebers
D O
DO
O'Fallon
W M
WM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D011336:Probability; D012008:Recurrence; D013345:Subarachnoid Hemorrhage / Q000401:mortality* / Q000628:therapy; D013997:Time Factors; D014481:United States