Prehospital stroke scales in urban environments: a systematic review

Objective: To identify and compare the operating characteristics of existing prehospital stroke scales to predict true strokes in the hospital.

Methods: We searched MEDLINE, EMBASE, and CINAHL databases for articles that evaluated the performance of prehospital stroke scales. Quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. We abstracted the operating characteristics of published prehospital stroke scales and compared them statistically and graphically.

Results: We retrieved 254 articles from MEDLINE, 66 articles from EMBASE, and 32 articles from CINAHL Plus database. Of these, 8 studies met all our inclusion criteria, and they studied Cincinnati Pre-Hospital Stroke Scale (CPSS), Los Angeles Pre-Hospital Stroke Screen (LAPSS), Melbourne Ambulance Stroke Screen (MASS), Medic Prehospital Assessment for Code Stroke (Med PACS), Ontario Prehospital Stroke Screening Tool (OPSS), Recognition of Stroke in the Emergency Room (ROSIER), and Face Arm Speech Test (FAST). Although the point estimates for LAPSS accuracy were better than CPSS, they had overlapping confidence intervals on the symmetric summary receiver operating characteristic curve. OPSS performed similar to LAPSS whereas MASS, Med PACS, ROSIER, and FAST had less favorable overall operating characteristics.

Conclusions: Prehospital stroke scales varied in their accuracy and missed up to 30% of acute strokes in the field. Inconsistencies in performance may be due to sample size disparity, variability in stroke scale training, and divergent provider educational standards. Although LAPSS performed more consistently, visual comparison of graphical analysis revealed that LAPSS and CPSS had similar diagnostic capabilities.