Little information has been available about the fact that the incidence of severe SAH differs among hospitals, though the fact is important as a basis of many statistical analyses of SAH. We, therefore, investigated in this study the difference in severity of SAH among hospitals and considered the cause of the variation. SAH caused by aneurysmal rupture (1064 cases in the total) in each of sixteen hospitals with different emergency systems was analyzed from the standpoint of the Hunt and Kosnik grading at admission and the timing of admission. All the patients admitted to a hospital were investigated in six hospitals (Group A) and only the patients admitted to the neurosurgical department were investigated in ten other hospitals (Group B). The distribution patterns of the Hunt and Kosnik grading (grade-patterns) varied widely among seven hospitals that had more than 50 cases, especially in the rate of Grade V (2.9% to 37%). Next, the Group A cases were investigated from the standpoint of timing of admission. The rate of Grade V was about three times higher in patients of day 0 admission (24.8%) than in those of d 1-d 3 admission (8.5%). Analyzing the timing of admission we found two types of hospital: Type 1 that mainly received emergency cases (d 0 patients>70%), and Type 2 that mainly received cases from affiliated hospitals (d 0 patients<30%). The rate of Grade V in the Type 1 hospitals (26.1%) was about three times higher than that of the Type 2 hospitals (7.0%). This result indicated that a considerable number of Grade V patients were excluded before admission in the Type 2 hospitals. The rate of Grade V on d 0 was about three times higher in Group A (24.8%) than in Group B (8.7%). The results indicated that the inoperable cases admitted to internal medicine were excluded from the list of neurosurgery candidates. However a comparative study of d 0 cases among hospitals of Group A still showed a wide variety in the rate of Grade V patients (14.5%-43.5%). The results seemed to indicate that severe SAH cases were unequally distributed among hospitals in the process of direct delivery from the place of onset. In conclusion it is assumed that patients with severe SAH had three screenings in the course of admission.
1. Screening by the emergency transfer route.
2. Screening before admission to Type 2 hospitals.
3. Screening by the department in the hospital.
