FIG. 4.

Study 2 (valproate [VPA]) had codes for the reason for the missing data measured at 1 month (A), 6 months (B), and 12 months (C) to confirm hypotheses about why outcome data were missing for different groups of patients in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) Pilot, blocked by Glasgow Outcome Scale (GOS) severity. As expected, patients from the VPA study who were higher functioning (green) were less likely to participate in follow-up care, potentially a as a result of a lack of interest in staying in the study because they did not have a measurable disability. Whereas patients with severe disability (red) were more likely to have missing data because of central nervous system (CNS) problems preventing them from performing the task. Patients who started in a vegetative state (white) at 1 month generally could not be assessed because of CNS complications, with, presumably, patients moving to either the red category (out of a vegetative state, severe disability), or into the black category (dead). Color image is available online.