*University of Iowa Carver College of Medicine, Iowa City, Iowa; †Institute for Orthopaedics, Sports Medicine and Rehabilitation, Iowa City, Iowa; and ‡Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, Iowa.
OBJECTIVE:: To determine the amount of within-day variation of Concussion Symptom Severity Scores (CSSSs) in athletes with a clinically diagnosed concussion.
DESIGN:: This prospective cohort study used a text-messaging robot to survey concussed athletes using the CSSS 5-times daily while they remained symptomatic. SETTING:: Academic sports concussion clinic at a large tertiary care medical center. PARTICIPANTS:: Fourteen 14- to 22-year-old athletes with clinically diagnosed concussions were enrolled. All were injured in sport, still in season, English speaking, and used a cellular telephone to text message on a regular basis. ASSESSMENT OF RISK FACTORS:: This study did not collect any demographic or other information about the subjects. The only data collected were the individual responses to the questions in the Post Concussion Symptom Score (PCSS). The only aim of this study was to evaluate the variability in responses to the CSSS, which is calculated from the PCSS. MAIN OUTCOME MEASUREMENTS:: The primary outcome measure was a repeatability coefficient from a random-effects model. Concussion Symptom Severity Score, mean daily CSSS, and standard deviation of CSSS differences from the mean were also calculated.
RESULTS:: Mean follow-up was 23.9 days. A total of 24 180 text messages were received from subjects. Eight hundred four complete surveys were analyzed. Repeatability coefficient was ±23.1.
CONCLUSIONS:: When surveyed frequently by a text-messaging robot, concussed athletes report poorly repeatable Sport Concussion Assessment Tool 2 (SCAT2) Symptom Severity Scores. CLINICAL RELEVANCE:: The SCAT2 Symptom Severity Score may be an invalid method of tracking concussion severity and resolution over time.