Mental and Physical Health Comorbidities in Traumatic Brain Injury: A Non-TBI Controls Comparison

Objective To examine whether ageing with a TBI was associated with a greater burden of health-related comorbidities compared to a non-TBI control cohort, and examine the associations between comorbidity burden, emotional outcomes, and health-related quality of life (HRQoL) after TBI across ages. Design Cross-sectional. Setting Research centre or telephone. Participants The study included 559 participants (NTBI=291, NControls=268). Participants with TBI were recruited during inpatient rehabilitation and had sustained a moderate-severe TBI 1-33 years previously. Non-TBI controls were a convenience sample recruited through advertisements in the community. Interventions Not applicable. Main Outcome Measures The number of cardiovascular, general physical health, and mental health comorbidities was compared between cohorts and age strata using Poisson regression. The relationships between comorbidities, age, emotional outcomes (Generalized Anxiety Disorder Scale-7, Patient Health Questionnaire-9) and HRQoL (PROMIS Global Health Measure) were examined with linear regression. Distinct subgroups of comorbidities were identified using latent class analysis. Associations between comorbidity classes with demographic and outcome variables were evaluated using multinomial logistic and linear regressions, respectively. Results TBI participants had a significantly higher comorbidity burden than controls, primarily driven by elevated rates of mental health disorders (RR = 2.71, 95% CI [1.37, 5.35]). Cardiovascular and physical health comorbidities were not elevated in the TBI group compared to controls. Both cohorts had three similar comorbidity subgroups, suggesting consistent patterns of co-occurring health conditions regardless of TBI exposure. Physical and mental health comorbidities were associated with elevated depression and anxiety symptoms and diminished HRQoL after TBI compared to controls. Conclusion TBI was associated with greater mental, but not physical, health comorbidities in the decades following injury. However, physical and mental health comorbidities significantly impacted emotional and HRQoL status after TBI, underscoring a greater need for long-term support for individuals with TBI coping with both physical and mental health comorbidities.