Delayed diagnosis of aneurysmal subarachnoid hemorrhage in patients: a community-based study

Abstract

A community-based study was conducted to estimate the frequency of and evaluate the clinical features related to delayed diagnosis of aneurysmal subarachnoid hemorrhage (SAH). Between 1980 and 1998, 358 patients with aneurysmal SAH underwent treatment in Izumo, Japan. The diagnosis of SAH was delayed in 76 patients (21%) and was early in 282 (79%). Among the 76 patients whose diagnosis was delayed, the condition was misdiagnosed by clinicians in 46 cases (Subgroup A), and in the remaining 30 the patients were unaware that SAH had occurred and failed to seek prompt treatment (Subgroup B). The proportion of Subgroup A patients decreased significantly from 18% (30 of 170 patients) between 1980 and 1989 to 9% (16 of 188 patients) between 1990 and 1998 (p = 0.0098), whereas the proportion of Subgroup B patients during the same periods was 8% (13 of 170 patients) and 9% (17 of 188 patients), respectively (p = 0.6341). With regard to Subgroup A, the misdiagnosis rate in private clinics decreased from 14% (23 of 170 patients) between 1980 and 1989 to 5% (10 of 188 patients) between 1990 and 1998 (p = 0.0073), whereas the misdiagnosis rate in hospitals during the same periods was 4% (7 of 170 patients) and 3% (6 of 188 patients), respectively (p = 0.6399). Multivariate analysis revealed that World Federation of Neurosurgical Societies Grade I or II was the main risk factor for delayed diagnosis of SAH (OR 3.97 [95% CI 1.69-10.37]), and that the timing of SAH onset, that is, between 12:00 a.m. and 6:00 a.m., was an important reason for the condition in Subgroup B patients (OR 9.29 [95% CI 2.66-33.93]). Rebleeding before admission occurred in 26% of the patients in whom diagnosis was delayed, and in 3% of those who were diagnosed early (p < 0.0001). Although the rate of SAH misdiagnosis seems to be decreasing, failure of patients to present for prompt treatment is unlikely to decrease unless the public becomes better educated about SAH and the importance of getting prompt medical attention, even in the middle of the night.