Has there been a decline in subarachnoid hemorrhage mortality?

Area of Science:

• Neurology
• Epidemiology
• Public Health

Background:

• Subarachnoid hemorrhage (SAH) is a critical neurological condition with significant mortality.
• Understanding long-term trends in SAH incidence and mortality is crucial for public health planning.

Purpose of the Study:

• To analyze the incidence, mortality, and case-fatality rates of subarachnoid hemorrhage in Rochester, Minnesota, over a 40-year period.
• To identify trends and potential factors influencing these epidemiological measures.

Main Methods:

• Retrospective population-based study of subarachnoid hemorrhage cases in Rochester, Minnesota (1945-1984).
• Analysis of incidence rates, age-specific incidence, mortality rates, and case-fatality rates.
• Comparison of trends over different time intervals and with national data for US white men and women.

Main Results:

• The annual incidence rate of subarachnoid hemorrhage remained constant at approximately 11 per 100,000 population.
• Age-specific incidence rates increased with age.
• The annual mortality rate for subarachnoid hemorrhage showed a decreasing trend, from 6.8 to 4.3 per 100,000 population.
• Case-fatality rates decreased from 57% to 42% between 1945-1974 and 1975-1984.
• Decreasing mortality trends were observed in US white men and women.
• The interval from SAH onset to surgery decreased significantly, and more patients received medical treatment in later years.

Conclusions:

• While subarachnoid hemorrhage incidence is stable, mortality rates have declined, likely due to improved case-fatality.
• Changes in medical management, including reduced time to surgery and increased treatment, may be contributing factors.
• Further research is needed to definitively link management changes to improved survival rates in subarachnoid hemorrhage.