Objectives

Post concussion, approximately 15% of cases will experience ongoing symptoms for months after the injury. This prolongs recovery and return to pre-injury activity. This group can benefit from individualised treatment of symptoms within a concussion clinic. The study evaluates the predictive value of post concussion symptom clusters on patients’ activity levels on discharge from the Epworth Rehabilitation Concussion Clinic.

Method

The Clinic administers the Oregon Post Concussion Symptom Checklist on admission and discharge. It consists of 23 symptoms, which the patient rates between 0 – 6 in severity. The list is grouped by symptom clusters (physical, cognitive, emotional and sleeping deficits).

Results

These preliminary results reflect patients currently discharged from the clinic (n=63). Patients were admitted on average, 88.8 days post injury (SD = 149.4), the average age was 33.2 years (SD=14.8) and the majority were male (68%). The primary causes of concussion were sport-related (41.3%), falls (23.8%) or motor vehicle accidents (12.7%). A prior history of concussion was present in (57.1%).

Cronbach's alpha, a measure of internal consistency, was calculated for each of the above symptom clusters. Alpha was high for Physical (0.85), Thinking (0.92) and Emotional (0.92), with all items exhibiting item-total correlations) =>0.40. 

The scale was evaluated at a symptom level, to determine whether specific predictors exist for worsening performance on discharge. Linear regression (controlling for age, gender, time elapsed since injury and past history of concussion), and entering all 23 items simultaneously identified sensitivity to light (p = 0.008) and noise (p = 0.021), dizziness (0.062), difficulty concentrating (0.097), emotional irritability (0.086) and sleeping more than usual (p = 0.082) as achieving or approaching statistical significance. For each one point increase in symptom severity, final adjusted activity levels were reduced by: 14.4% for sensitivity to light, 10.1% for dizziness, 6.4% for emotional irritability and 1.7% for difficulty concentrating. 

Conclusions

In this preliminary study, specific symptom severity on admission was found to have predictive value related to outcome on discharge. This information can be used for rehabilitation program development to achieve better functional outcomes and symptom resolution after concussion. The study is continuing and more formal scale development, including Rasch modelling is planned.

The Predictive Value of Persisting Post Concussion Symptoms on Recovery Trajectories