Clinical Cut Point for the Pittsburgh Sleep Quality Index After Adolescent Concussion

Background: Concussions can have negative implications for sleep quality. Self-report measures, such as the Pittsburgh Sleep Quality Index (PSQI), have been used in clinical and research settings to identify individuals with sleep impairments. However, the accuracy/applicability of historically established PSQI scoring criteria for differentiating good versus poor sleep quality has not been critically examined in adolescents with concussion. Purpose: To establish a relevant PSQI clinical cut point for adolescents with a recent concussion. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Adolescents within 16 days of concussion and uninjured controls completed the PSQI, and a global score of 0 to 21 was calculated. Independent-samples t tests were used to compare PSQI global scores, and logistic regression was used to calculate odds ratios (outcome = group; predictors = PSQI, covariates). A receiver operating characteristic curve was used to evaluate the area under the curve (AUC) and determine the optimal cut point to distinguish between adolescents with and without a concussion. Results: A total of 110 adolescents with a concussion (mean age, 14.9 ± 1.6 years; 53% female; 9.8 ± 3.6 days since injury) and 129 uninjured controls (mean age, 15.6 ± 1.1 years; 86% female) were included for analysis. The concussion group had significantly worse (higher) PSQI scores than controls (mean, 7.41 ± 3.62 vs 2.26 ± 1.97; P < .001; Cohen d = 1.8). Both the univariable model and multivariable model (controlling for age, sex, concussion history, history of anxiety and/or depression, and self-reported use of sleep medication) had excellent diagnostic accuracy (univariable AUC, 0.90; multivariable AUC, 0.99). Within the multivariable model, a cut point of 4 correctly classified 81% of participants as concussed or control (sensitivity, 87%; specificity, 74%). Conclusion: Adolescents with a concussion demonstrated worse sleep quality than uninjured controls. The results suggest that sleep quality, as measured by the PSQI, can distinguish between adolescents with and without a concussion, using a cut point of 4.