THE UTILITY AND VALIDATION OF THE FREQUENCY OF CONCUSSION SYMPTOMS (FOCS) QUESTIONNAIRE

BACKGROUND: Individuals with concussion show elevated scores on symptom checklists as long as the impairment is detectable (Peterson et al., 2003). The research question was to examine whether a questionnaire based on concussion symptom frequency (FOCS) would demonstrate sensitivity and specificity in differentiating concussion from non-concussion and provide beneficial clinical data when added to symptom severity measures such as the PCSS. PURPOSE: The purpose of this study was to determine the clinical utility of concussion symptom frequency using the Frequency of Concussion Symptoms (FOCS) Questionnaire in a sample of pediatric patients. METHODS: Pediatric patients ages 13-18 diagnosed with a concussion (n=250) and orthopedic controls (n=250) presenting to an outpatient orthopedic clinic were administered the FOCS and PCSS at the time of initial clinical evaluation. All patients were administered the FOCS and PCSS by certified athletic trainers who were educated and trained on administration. The Frequency of Concussion Symptoms (FOCS) Questionnaire is a self-report measure consisting of 28 items, rated on a 5-point scale from 4 (constantly) to 0 (never). The PCSS is a self-report measure consisting of 22 items rated on a 7-point scale from 0 (none) to 6 (severe). Demographic data were summarized using descriptive statistics. Point estimates and 95% confidence intervals were calculated for all end points. Pearson correlations were calculated based on numerical values from the FOCS and PCSS data to establish validity. A regression analysis was performed to examine the coefficient of determination for FOCS and PCSS scores. RESULTS: The total concussion sample consisted of 103 females and 147 males (mean age=15.03, SD=1.38), the orthopedic control sample consisted of 92 females and 158 males (mean age=15.46, SD=1.12). There was a positive correlation between the FOCS and PCSS in concussion patients (r=0.73, p=0.002) and in orthopedic controls (r=0.68, p=<0.001). Concussion and orthopedic control samples were not correlated on the FOCS (r=0.09, p<0.001) and PCSS (r=0.21, P=0.02). Multiple regression analysis was used to measure FOCS and PCSS scores in concussion patients (R(2)=0.78, p=<0.001). CONCLUSIONS: This is the first study of its kind examining concussion symptom frequency and severity to improve clinical symptom reporting. Adding frequency to symptom severity accounted for 78% of the variance. This may be the result of less subjectivity in frequency versus severity. This study was limited by sample size, further research is warranted to explore the relationship between symptom frequency and severity.