The Stability of Retrospective Pre-injury Symptom Ratings Following Pediatric Concussion.

Objective: To determine the stability of children’s retrospective ratings of pre-injury levels over time following concussion. Methods: Children and adolescents (n=3,063) between the ages of 5-17 diagnosed with a concussion by their treating PED physician within 48hrs of injury completed the age-appropriate version of the Post-Concussion Symptom Inventory (PCSI) at the PED and at 1, 2, 4, 8, and 12-weeks post-injury. At each time point, participants retrospectively recalled their pre-injury levels of post-injury symptoms. Total scale, subscales (physical, cognitive, emotional, and sleep), and Individual items from the PCSI were analyzed for stability using Gini’s mean difference (GMD). Results: The mean GMD for total score was 0.31 (95% CI= 0.28, 0.34) for the PCSI-SR5, 0.19 (95% CI= 0.18, 0.20) for the PCSI-SR8, and 0.17 (95% CI= 0.16, 0.18) for the PCSI-SR13. Subscales ranged from mean GMD 0.18 (physical) to 0.31 (emotional) for the PCSI-SR8 and 0.16 (physical) to 0.31 (fatigue) for the PCSI-SR13. At the item-level, mean GMD ranged from 0.13-0.60 on the PCSI-SR5, 0.08-0.59 on the PCSI-SR8, and 0.11-0.41 on the PCSI-SR13. Conclusions: Children and adolescents recall their retrospective pre-injury symptom ratings with good-to-perfect stability over the first three-months following their concussion. Although some individual items underperformed, variability was reduced as items were combined at the subscale and full-scale level. There is limited benefit gained from collecting multiple pre-injury symptom queries. This study is registered at Clinicaltrials.gov through the US National Institute of Health/National Library of Medicine. (NCT01873287; http://clinicaltrials.gov/ct2/show/NCT01873287).