How severe should symptoms be before someone is said to be suffering from post-concussion syndrome? An exploratory study with self-reported checklist using Rasch analysis

PRIMARY OBJECTIVE: This study aimed to examine the diagnosis of post-concussive symptoms among a group of people with subjective post-concussive symptoms (PCS) complaints using a self-reported checklist. RESEARCH DESIGN: A cross-sectional design was adopted with a total of 92 patients with PCS and 123 normal controls. METHODS AND PROCEDURES: The Rivermead Post-concussion Symptoms Questionnaire was administered to all participants. Analysis using the Rasch Model was undertaken. MAIN OUTCOMES AND RESULTS: The common matrix of symptom profiles indicated significant effects of gender (p < 0.005) and litigation (p < 0.0004). The patient group reported significantly higher symptoms than the healthy group (p < 0.0001) with differential symptom endorsement along the logits unit continuum. CONCLUSIONS: The application of Rasch model analysis successfully set up a common matrix to discriminate patients with post-concussive symptoms from healthy people along the logits unit continuum.