Validation of the Cincinnati Prehospital Stroke Scale

Early recognition of Stroke is one of the key concepts in the "Chain of Survival" as described by the American Heart Association/American Stroke Association Stroke guidelines. The most commonly used tools for prehospital assessment of stroke are "The Cincinnati Prehospital Stroke Scale," (CPSS) the "Face, Arm, Speech Test," and "The Los Angeles Prehospital Stroke Screen." The former two are used to identify stroke using physical findings while the latter is used to rule out other causes of altered consciousness.

The aim of this study is to validate the CPSS in the prehospital setting by correlating with computed tomography scan findings. (1) To determine if these scores can be implemented in the Indian prehospital setting. (2) To determine if it is feasible for new emergency departments (EDs) to use these protocols for early detection of stroke.

A prospective, observational study from December, 2015 to March, 2016. Patients with suspected stroke were enrolled. Data were collected prehospital in patients that arrived to the ED in an ambulance. Sensitivity, specificity, positive predictive value, and negative predictive value of the score were calculated using standard formulae.

CPSS showed good sensitivity of 81% (confidence interval [CI] - 68.5%-97%) when combined and a positive predictive value (PPV) of 100% (CI: 91.9%-100%). Individually, they showed a sensitivity of 75.8%, 79%, and 74.1%, respectively, with a PPV of 100% and specificity of 95%-100%.

As a prehospital screening tool, CPSS can be extremely useful as any diagnosis is only provisional until confirmed by an appropriate investigation in a hospital.