Subarachnoid hemorrhage and family history. A population-based case-control study.
OBJECTIVE
To evaluate family history as a risk factor for subarachnoid hemorrhage.


METHODS
A population-based case-control study in King County, Washington.


METHODS
Cases consisted of 149 patients with spontaneous subarachnoid hemorrhage. Two control subjects who were matched to cases by gender and age within 5 years were identified for each case using random digit telephone dialing.


METHODS
Detailed information on family history was obtained through an in-person interview.


RESULTS
Some 11.4% of cases had a first-degree relative with a history of subarachnoid hemorrhage, compared with 6.4% of controls, yielding an odds ratio of 1.8 (95% CI, 0.92 to 3.7). The odds ratio for a positive family history among other relatives was 2.4 (95% CI, 1.1 to 5.2), likely reflecting family information bias. Findings were similar after adjustment was made for potential confounding variables, including cigarette smoking, a history of hypertension, and number of siblings and children.


CONCLUSIONS
Although familial factors may be important in some families, overall they account for few cases of subarachnoid hemorrhage.
Wang
P S
PS
Department of Epidemiology, Tianjin Medical College, China.
Longstreth
W T
WT
Koepsell
T D
TD
D016022:Case-Control Studies; D005190:Family; D005260:Female; D006801:Humans; D006973:Hypertension; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012907:Smoking; D013345:Subarachnoid Hemorrhage / Q000453:epidemiology / Q000235:genetics*