Reliability and validity of the Clinical Neurologic Assessment (CNA) Tool in children with head trauma

Abstract

The Clinical Neurologic Assessment (CNA) Tool is a 21 item instrument designed to assess subtle neurologic changes that often accompany head trauma. This descriptive study was designed to test the reliability and validity of the CNA in children with head trauma. Interrater reliability of the CNA was assessed by determining Cohen's Kappa values for each item. Kappa values ranged from .74 to 1.00. Internal consistency of the CNA was assessed using Cronbach's alpha. The total CNA alpha was estimated to be .98 with subscale alphas ranging from .89 to .96. Concurrent and construct validity of the CNA were also assessed. Concurrent validity was estimated by determining Pearson's Product-Moment Correlation Coefficients for the CNA and the Glasgow Coma Scale (GCS) (r = .93; p = .001). Pearson's correlation coefficients were also estimated based on severity of head trauma (r = .57 to .74; p ≤ .017) and the age of the subject (r = .89 to .99; p ≤ .001). Construct validity was assessed using exploratory factor analysis which demonstrated a three factor solution. These factors reflected the following: a general overview of the level of consciousness, overall body and extremity position and movement, and muscle tone of the extremities.