Clinical scales might vary across populations, in order to offer an accurate prognosis and subsequent management a proper validation is a necessary. An original study by Takagi et al, 1999 designed the PAASH scale to predict patient outcome of aSAH using only the Glasgow Coma Sacale (GCS) on admission in a Japanese cohort. However, the  performance of the PAASH scale in Mexican population has not been studied before. Clinical scales might vary across populations, thus in order to offer an accurate prognosis and subsequent management a proper validation is a necessary.  We aim to evaluate this scale and compared it to the original study.

We included a cohort of 150 patients consecutively admitted from 2017 to 2018 from the National Institute of Neurology and Neurosurgery with the diagnosis of aSAH. GCS and PAASH were obtained on admission. Outcome was assessed by the Glasgow Outome Scale (GOS) at six months after hospital discharge. Differences between grades of the PAASH scale were calculated. We used a ROC curve to identify the best cut-off point for a poor prognosis (GOS at 6 months ≥4), and the percentage of poor outcome was compared per PAASH category between the original study and our cohort.

The ROC curve was statistically significant (0.908 95% confidence CI .845- .972 P 0.0001). The optimum cut-off point for poor outcome identified in the PAASH scale is 2 with a sensitivity of 90% and specificity of 73% with an AUC of 0.908. No differences were found between the cohorts.

The PAASH scale showed excellent performance to discriminate a good and a poor prognosis at 6 months in the Mexican population. Compared to the original study, the PAASH scale has a very similar performance.