Psychometric Properties and Validation of the General Anxiety Disorder 7-Item Scale Among Adolescents With Persistent Post-Concussive Symptoms.

The General Anxiety Disorder 7-Item (GAD-7) scale is commonly used in primary care as a self-report measure of general anxiety symptoms with adult populations. There is little psychometric research on this measure with adolescent populations, particularly those with persistent post-concussive symptoms (PPCS). This study examined the psychometrics properties of the GAD-7 among youth with PPCS. We used baseline data from a randomized controlled trial of collaborative care for treatment of PPCS among 200 sports-injured adolescents 11-18 years of age (Mage = 14.7 years, standard deviation = 1.7). Eligible adolescents had three or more PPCS that lasted for ≥1 month and spoke English. Adolescents reported on their anxious (GAD-7 and Revised Child Anxiety and Depression Scale-Short Version [anxiety subscale]; RCADS) and depressive (Patient Health Questionnaire-9; PHQ-9) symptoms. Parents used the RCADS to report on their adolescents' anxious symptoms. The GAD-7 had good internal validity (Cronbach's alpha = 0.87), and significant (p < 0.001) correlations were detected between the GAD-7 and youth and parent report of anxiety on RCADS (r = 0.73 and r = 0.29) and PHQ-9 (r = 0.77) scores. Confirmatory factor analysis suggested a one-factor solution. These results suggest that the GAD-7 is a valid measure of anxiety with good psychometric properties for youth experiencing PPCS. ClinicalTrials.gov identifier: NCT03034720.