Validity of Single-Item Patient-Rated Outcomes in Adolescent Football Athletes with Concussion

Objective: To determine the longitudinal and concurrent validity of single-item patient-rated outcomes (PROs) in adolescent football athletes with concussion. Design: Longitudinal. Setting: Athletic training facilities. Participants: Convenience sample of male adolescent interscholastic athletes (n=94; mean age, 15.7±1.1y; mean grade, 10.1±1.1) from a larger investigation who suffered a sport-related concussion during football and had at least 3 follow-up assessments at 3, 10, and 30 days postinjury (N=249). Interventions: Not applicable. Main Outcome Measures: Participants were administered 3 global rating questions (1 generic, 1 for daily activities, and 1 for athletic activities) along with the Pediatric Quality of Life Inventory (PedsQL), Multidimensional Fatigue Scale (MFS), and Headache Impact Test-6 (HIT-6) at 3, 10, and 30 days postconcussion. Longitudinal validity was determined through a mixed linear model with random effects for subjects, with pairwise differences assessed using Bonferroni correction (P<.05). Concurrent validity was determined by examining Spearman ρ correlations between the single-item PROs and multi-item PROs. Results: All 3 single-item PROs improved over time, demonstrating longitudinal validity (P<.001), except day 10 versus day 30 for global change (P=.072). Fair to moderate correlations were identified between the single-item PROs and the PedsQL, MFS, and HIT-6. Conclusions: The improvement of single-item PRO scores over a postinjury time period of 30 days suggests that these PROs respond as expected to patient recovery. The correlations identified between the single-item PROs and common multi-item PROs used in athletes with concussion demonstrate concurrent validity. Therefore, single-item PROs appear to measure patient progress in adolescent football athletes postconcussion.