4 The Role of Cognition and Self-Awareness on Driving Patterns After Moderate-to-Severe Traumatic Brain Injury

Abstract

Objective:

Return to driving after moderate-to-severe traumatic brain injury (TBI) is often a key step in recovery to regain independence. Survivors are often eager to resume driving and may do so despite having residual cognitive limitations from their injury. A better understanding is needed of how cognition and self-awareness impact survivors’ driving after injury. This study examined the influence of cognition and self-awareness on driving patterns following moderate-to-severe TBI.

Participants and Methods:

Participants were 350 adults aged 19-87 years (mean age = 46 years; 70% male) with history of moderate-to-severe TBI, who resumed driving and were enrolled in the TBI Model System. Cross-sectional data were obtained ranging 1-30 years post injury, including questions on driving practices, the Brief Test of Adult Cognition by Telephone (BTACT), and the Functional Independence Measure (FIM). Self-awareness of cognitive function was measured via the discrepancy between dichotomized ratings (intact versus impaired) of objective cognitive testing (BTACT) and self-reported cognitive function (FIM Cognition subscale). Driving patterns included frequency (driving 'more than once a week’ versus 'once a week or less') and restricted driving behavior (total number of driving situations the survivor described as restricted, ranging 0-15). Regression analyses were conducted to examine the relationships between cognition, self-awareness, and each driving outcome (frequency and restriction), followed by causal mediation analyses to examine the mediating effect of self-awareness. Demographics (age, sex, education), injury characteristics (time since injury, injury severity, history of seizures in past year), and medical/social factors (family income, motor function, urban-rural classification) were included in the models as covariates.

Results:

Thirty-nine percent of survivors had impaired self-awareness, 88% of survivors drove numerous times per week, and the average survivor reported limited driving in 6 situations (out of 15 total situations). Cognition was inversely related to impaired self-awareness (OR = 0.03, p < 0.001) and inversely related to restricted driving behavior (b = -0.79, p < 0.001). Motor function was positively related to impaired self-awareness (OR = 1.28, p < 0.01). Cognition was not related to driving frequency, and self-awareness did not mediate the relationships between cognition and driving patterns (all p > 0.05).

Conclusions:

Most survivors who drive after their injury are driving frequently, but the situations they drive in differ based on their cognitive ability. Impaired self-awareness of cognitive deficits is common after TBI, and self-awareness of cognitive function does not affect driving patterns. Future research needs to focus on how cognition affects nuanced aspects of driving behavior after injury (i.e., types of situations survivors drive in).