Patterns and predictors of ten-year mortality after discharge from community-based post-acute care for acquired brain injury: A retrospective cohort study (ABI-RESTaRT), Western Australia, 1991–2017

Survivors of acquired brain injury (ABI) are left with long-term disability and an increased risk of mortality years post-injury. To examine 10-year mortality in adults with ABI after discharge from post-acute care and identify modifiable risk factors to reduce long-term mortality risk. Retrospective cohort study of 586 adults with traumatic (TBI) or non-traumatic brain injury (NTBI), or neurologic condition, consecutively discharged from a post-acute rehabilitation service in Western Australia from 1-Mar-1991 to 31-Dec-2017. Data sources included rehabilitation records, and linked mortality, hospital, and emergency department data. Survival status at 10 years post-discharge was determined. All-cause and cause-specific age- and sex-adjusted standardised mortality ratios (SMR) by ABI diagnosis were calculated using Australian population reference data. Risk factors were examined using multilevel cox proportional hazards regression. Compared with the Australian population, 10-year all-cause mortality was significantly elevated for all diagnosis cohorts, with the first 12 months the highest risk period. Accidents or intentional self-harm deaths were elevated in TBI (13.2, 95%CI 5.4; 12.1). Neurodegenerative disease deaths were elevated in Neurologic (21.9, 95%CI 13.0; 30.9) and Stroke (19.8; 95%CI 2.4; 27.2) cohorts. Stroke (20.8; 95%CI 7.9; 33.8) and circulatory disease deaths (6.2; 95%CI 2.3; 9.9) were also elevated in Stroke. Psychiatric comorbidity was the strongest risk factor followed by older age, geographical remoteness, and cardiac, vascular, genitourinary and renal comorbidity. Clinically significant improvement in functional independence and psychosocial functioning significantly reduced mortality risk. Individuals with ABI have an elevated risk of mortality years post-injury. Comorbidity management, continuity of care, and rehabilitation are important to reduce long-term mortality risk.