Construct validity of the ImPACT post-concussion scale in children

British Journal of Sports Medicine. 2004 Oct;


Janusz, J. A., G. A. Gioia, K. Gilstein and G. L. Iverson.



Introduction: Assessment of sequelae following a concussion typically involves the use of a post-concussion symptom inventory. In its current form, the ImPACT Post-Concussion Scale (PCS) provides an overall total rating of 22 symptoms. To improve clinical utility, it may be useful to differentiate specific components. Recently, Moritz et al described specific clusters of core symptoms in adults on the PCS. We examined the factor structure of the PCS among the youngest sample of children yet studied to date. Methods/Results: The PCS was administered to a sample of 750 children, aged 11 through 18 years, including children with (n = 115) and without (n = 635) history of concussion. The 22-item scale was submitted to a principal factor analysis with Promax rotation. Examination of competing solutions supports a four-factor solution as most statistically and theoretically sound, accounting for 47.4 percent of the variance. The solution is defined by a Somatic Symptoms factor (7 items), a Cognitive Problems factor (6 items), a Sleep/Fatigue Problems factor (4 items), and an Affective Problems factor (5 items). Internal consistency reliabilities were acceptable for the four factors: Somatic Symptoms α = 0.84, Cognitive Problems α = 0.81, Sleep Problems α = 0.78, and Affective Problems α = 0.75. Conclusions: Examination of the factor structure of a pediatric version of the ImPACT -PCS reveals four specific domains of post-concussive symptoms, supporting the use of these subscales, in addition to total symptom score, in clinical interpretation. Although the number and type of factors obtained with this large pediatric normative sample was similar to adult samples, items comprising each factor were different. Future research will expand the focus of symptom report in children younger than 11.

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