Clinical Cut Point for the Postconcussion Symptom Inventory Following Adolescent Concussion.

BACKGROUND

The Postconcussion Symptom Inventory (PCSI) evaluates the severity of 21 concussion-related symptoms, yielding a total symptom severity between 0 and 126. Although widely used in concussion research and care as a key element in diagnosis and management decisions, no clinically validated cut point exists to distinguish adolescents with and without a recent concussion. Therefore, the purpose of our study was to establish a PCSI cut point with adequate sensitivity, specificity, and classification accuracy for clinical use.

METHODS

Adolescents within 21 days of concussion and uninjured controls completed the PCSI, and total symptom severity score was calculated. We used independent samples t tests to compare total PCSI symptom severity scores between groups, and multivariable logistic regression to calculate adjusted odds ratios (outcome = group, predictor = PCSI score, covariates = age, biological sex, concussion history, history of anxiety, and/or depression). A receiver operating characteristic (ROC) curve was used to evaluate the area under the ROC curve and determine the optimal cut point to distinguish between adolescents with and without a concussion.

RESULTS

One hundred fifty-three adolescents with a concussion (15.4 ± 1.6 years; 54% female; 8.2 ± 3.6 days since injury), and 200 uninjured controls (15.8 ± 1.1 years; 84% female) were included. The concussion group had significantly higher PCSI scores than the control group (47.4 ± 26.8 vs 20.9 ± 19.4; P < 0.001). The univariable area under the ROC curve value for the PCSI to differentiate between groups was 0.80 (95% confidence interval = 0.75-0.85), and correctly classified 74% of participants as concussion or control group using a PCSI cut point of 23 (sensitivity = 68%, specificity = 83%).

CONCLUSIONS

Our results suggest a PCSI cut point of 23 can distinguish between adolescents with and without a recent concussion and may provide enhanced accuracy to identify a suspected concussion in the subacute time after injury.