The Influence of Substance Use on Traumatic Brain Injury Recovery and Rehabilitation Outcomes: The Outcome-ABI Study

Objective: This study characterized substance use (alcohol, illicit drugs, amphetamines) in patients with traumatic brain injury (TBI) receiving rehabilitation to determine potential benefit of rehabilitation and whether substance use influenced outcomes in moderate-severe TBI.Design: Prospective, longitudinal study of adults with moderate or severe TBI receiving inpatient rehabilitation.Setting: Specialist-staffed acquired brain injury rehabilitation center in Melbourne, Australia.Participants: A total of 153 consecutive inpatients with TBI admitted between January 2016 and December 2017 (24 months).Interventions: All inpatients with TBI (n=153) received specialist-provided brain injury rehabilitation in accordance with evidence-based guideline care at one 42-bed rehabilitation center.Main Outcome Measures: Data were collected at time of TBI, upon rehabilitation admission, and discharge and 12 months' post-TBI. Recovery was measured by posttraumatic amnesia posttraumatic amnesia length-days and change in Glasgow Coma Scale (admission-discharge). Functional independence was measured on the FIM, Functional Assessment Measure, and Mayo Portland Adaptability Index. Quality of life (QOL) was measured on the EuroQOL-5D-5L and Quality of Life After Brain Injury (QOLIBRI) instruments.Results: Inpatients with history of illicit drug use (n=54) reported lower QOL and adjustment at 12 months' post-TBI compared with those with no history (QOLIBRI social relationships: ratio of means=0.808, P=.028; Mayo Portland Adaptability Index adjustment: incidence rate ratio, 1.273; P=.032). Amphetamine use at time of injury (n=10) was associated with quicker recovery (posttraumatic amnesia length-days: incidence rate ratio, 0.173; P<.01); however, lower QOL at 12 months post-TBI was noted in those with a history of amphetamine use (n=34) compared with those without (QOLIBRI bothered feelings: ratio of means, 0.489, P=.036).Conclusions: All participants made improvements with rehabilitation post-TBI; however, a history of substance use was associated with lower reported 12-month QOL. These findings add insight to the associations between substance use and acute recovery, potentially suggestive of a short-term recovery-promoting effect of amphetamines but highlighting the importance of rehabilitation to address long-term sequalae.