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.
Department of Epidemiology, Tianjin Medical College, China.
P S
PS
Wang
W T
WT
Longstreth
T D
TD
Koepsell
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*