Prediction of Subarachnoid Hemorrhage From a Ruptured Cerebral Aneurysm by Discriminant Analysis in Women

Background: Using a discriminant analysis study of Japanese women, we sought to construct a predictive model of individuals who are at a higher risk factor of the occurrence of subarachnoid hemorrhage (SAH) from a ruptured cerebral aneurysm. Methods: Patients consisted of a consecutive series of 124 female patients with first spontaneous SAH aged 30 to 79 years and aneurysm or aneurysms confirmed by angiography, computed tomography scan, or both at two medical hospitals in Nagoya, Aichi Prefecture, Japan, from April 1992 to March 1997. Community control subjects were identified, and matched to each patient by age (±2 years). Linear discrimination analysis was used to construct a predictive model to select individuals who have a higher chance of SAH. Results: All of the 5 predictor variables (lower antioxidant intake score, current smoking, family history of SAH, nulligravidity, and hypertension) were independently associated with the risk of SAH. The discriminant analysis yielded a statistically significant function, which explained 52% of the whole (canonical correlation [Rc] = 0.73; degrees of freedom [df] = 6; P = .000). This function showed that the rate of correct prediction was 76.2% for patients with SAH, and 82.7% for control subjects, and that it was able to produce an 80.4% rate of correct classification. Conclusions: The current study suggests that the calculated discriminant function, which was determined congenital (family history of SAH) and acquired variables simultaneously, may provide greater predictive accuracy for screening individuals at high risk of the occurrence of SAH in women. Prospective studies are needed to confirm validity and feasibility of the model for earlier screening for the occurrence of SAH in women.