Figure 2. Optimal classification and regression tree for participants who had computerized neurocognitive testing during initial visit.

The 129 patients who underwent computerized neurocognitive testing were analyzed separately to determine any added value of such testing in predicting symptom duration. Again, the most useful variable for distinguishing patients who had symptoms for longer than 28 days from those with shorter recoveries was Post-Concussion Symptom Scale (PCSS) score at the time of the initial visit. The optimal cutoff point changed slightly in this population, such that those with a PCSS score of 11 or higher at their initial visit were more likely to have symptoms that lasted beyond 28 days.