BACKGROUND:

Subarachnoid hemorrhage (SAH) is the cause of 5% to 10% of strokes annually in the United States.

OBJECTIVE:

To study the incidence and mortality trends of admissions of SAH from 1979 to 2008 using a nationally representative sample of all nonfederal acute-care hospitals in the United States: The National Hospital Discharge Survey.

METHODS:

The sample was obtained from the hospital discharge records according to the International Classification of Disease, 9th Revision, Clinical Modification code 430.

RESULTS:

We reviewed data on approximately 1 billion hospitalizations in the United States over a 30-year study period and identified 612 500 cases of SAH, which was more common in women (relative risk 1.71, 95% confidence interval 1.7-1.72) and nonwhite persons than white persons (relative risk 1.46, 95% confidence interval 1.4-1.5). The estimated incidence rate of admission after SAH was 7.2 to 9.0 per 100 000/year and did not significantly change over the study period. Overall, in-hospital mortality after SAH fell from 30% during the period from 1979 to 1983 to 20% during the subperiod from 2004 to 2008 (P=. 03) and was lower in larger treating hospitals. The average days of care for SAH hospitalizations decreased, but the rate of discharge to long-term care facilities increased.

CONCLUSION:

The incidence rate of admission after SAH has remained stable over the past 30 years. Total deaths and in-hospital mortality after SAH have decreased significantly. In-hospital mortality after SAH is lower in larger treating hospitals.

ABBREVIATIONS:

CI, confidence interval

ICD-9-CM, International Classification of Disease, 9th Revision, Clinical Modification

NHDS, National Hospital Discharge Survey

RSE, relative standard error

RR, risk ratio

SAH, subarachnoid hemorrhage

SE, standard error

Subarachnoid hemorrhage (SAH) causes 5% to 10% of strokes annually in the United States. 1 Population-based studies indicate that the incidence varies according to the geographic region. 2, 3 The outcome depends on several factors including age, severity, timing of treatment, intensive care unit management, and the incidence of medical complications. 1 Updated long-term nationwide studies regarding the epidemiology and trends in overall in-hospital mortality after SAH in the United States are currently lacking. In this study, we investigated the temporal trends in admissions of SAH using a representative sample of all nonfederal hospitals with specific attention to its admission rate, disposition, and in-hospital mortality. We hypothesized that the incidence rate of admissions and in-hospital mortality after SAH have not significantly changed over the past 30 years.