Objective: To evaluate inter-observer agreement and validity of an asthma severity score derived from wheeze, heart rate and accessory muscle use components.
Methodology: Children with acute asthma were examined independently and simultaneously by two observers, followed by pulse oximetry and spirometry in those over 5 years with repeatable measurements.
Results: Inter-observer agreement was very good (weighted kappa 0.82, 95% confidence interval 0.63 to 1.00), the component with the best agreement being the accessory muscle score (0.76, 0.57 to 0.95). The score correlated significantly with oxygen saturation, heart rate, and forced expiratory volume in 1 s (FEV1). In a multivariate model, FEV1 was best related to accessory muscle use.
Conclusions: The asthma severity score has very good inter-observer agreement with a moderate relationship to oxygenation and FEV1.