Risk stratification for the in-hospital mortality in subarachnoid hemorrhage: The HAIR score

Background: The intracerebral hemorrhage (ICH) score is a simple grading scale that can be used to stratify risk of 30 day mortality in ICH patients. A similar risk stratification scale for subarachnoid hemorrhage (SAH) is lacking. We sought to develop a risk stratification mortality score for SAH. Methods: With approval from the Institutional Review Board, we retrospectively reviewed 400 consecutive SAH patients admitted to our institution from August 1, 2006 to March 1, 2011. The SAH score was developed from a multivariable logistic regression model which was validated with bootstrap method. A separate cohort of 302 SAH patients was used for evaluation of the score. Results: Among 400 patients with SAH, the mean age was 56.9 ± 13.9 years (range, 21.5-96.2). Among the 366 patients with known causes of SAH, 292 (79.8 %) of patients had aneurysmal SAH, 65 (17.8 %) were angiogram negative, and 9 (2 %) were other vascular causes. The overall in-hospital mortality rate was 20 %. In multivariable analysis, the variables independently associated with the in-hospital mortality were Hunt and Hess score (HH) (p < 0.0001), age (p < 0.0001), intraventricular hemorrhage (IVH) (p = 0.049), and re-bleed (p = 0.01). The SAH score (0-8) was made by adding the following points: HH (HH1-3 = 0, HH4 = 1, HH5 = 4), age (<60 = 0, 60-80 = 1, ≥80 = 2), IVH (no = 0, yes = 1), and re-bleed within 24 h (no = 0, yes = 1). Using our model, the in-hospital mortality rates for patients with score of 0, 1, 2, 3, 4, 5, 6, and 7 were 0.9, 4.5, 9.1, 34.5, 52.9, 60, 82.1, and 83.3 % respectively. Validation analysis indicates good predictive performance of this model. Conclusion: The SAH score allows a practical method of risk stratification of the in-hospital mortality. The in-hospital mortality increases with increasing SAH mortality score. Further investigation is warranted to validate these findings.