Design and psychometric properties of Iranian pre-hospital stroke scale

  Background :The studies have shown that stroke morbidity and mortality could be decreased if early diagnosis and treatment is delivered faster for patients. This tool is designed based on all Pre-hospital stroke scales across the world as well as experiences of the emergency medicine specialists and pre-hospital emergency technicians to improve the diagnostic accuracy of the stroke scale in Iran.   Methods : This study used mixed methods and was carried out in two main phases. In the first phase (items generating ), concept elicitation was conducted based on the review of the literature related to stroke diagnosis and usual instruments in pre-hospital emergency stroke centers, and a series of semi- structured individual interviews with 35 neurologists, emergency medicine practitioners, and physicians working in hospitals and emergency technicians in the pre-hospital field participated. In the second phase (items reduction), the face and content validity, and reliability of the procedure were checked.   Results: According to results from the first phase of this study (items generation), three domains were introduced as the most important factors influence to detection of early signs and symptoms of stroke. In the second phase (items reduction), the face validity of this tool was based on the comments received from participants (the experts and EMS technicians), and changes were made for clarity of items. The content validity based on Lawshe index was identified. The S-CVI/Ave for Iranian Pre-Hospital stroke scale was calculated (89%). To determine the criterion validity of the instrument, he Iranian pre-hospital stroke scale scores were compared with the final diagnosis based on Brain CT scan result in hospital.   Conclusion : This study made an Iranian pre hospital stroke scale for emergency technicians in pre-hospital field which is dichotomous items, simple and very easy to use. For future this tool could be recommended and employed by emergency dispatch units as well as using it in the triage procedure in the hospital.