OBJECTIVES: To (1) detect distinct trajectories of symptoms and quality of life (QoL) over the first 4 years after mild traumatic brain injury (mTBI)
(2) assess the relationship between symptom trajectory membership and QoL trajectory membership
and (3) identify participant characteristics associated with QoL trajectory membership. DESIGN: Prospective longitudinal cohort study. Assessments occurred at 4, 8, 12, 24, 36, and 48 months after mTBI. SETTING: Recruitment occurred in Level 1 Trauma Centers
follow-up was completed in the community. PARTICIPANTS: Participants were 143 adults (aged 18-65y) who sustained an mTBI and were hospitalized (≥24h) at a Level 1 Trauma Center. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Fatigue Severity Scale, Hospital Anxiety and Depression Scale, Insomnia Severity Index, Medical Outcomes Study Cognitive Functioning Scale, Quality of Life after Brain Injury questionnaire, presence/absence of headaches or dizziness. RESULTS: Group-based trajectory modeling revealed relatively stable symptom and QoL trajectories over time. Considerable percentages of participants were classified in trajectories of clinically significant symptoms throughout the full follow-up period: 62% for subjective cognitive issues, 54% for fatigue, 44% for anxiety, 43% for insomnia, 27% for depression, 23% for headaches, and 17% for dizziness. Sixty-six percent of participants belonged to trajectories of persistently poor QoL. For all symptoms, trajectories of greater severity were associated with trajectories of poorer QoL. None of the sociodemographic or injury-related variables examined were associated with QoL trajectory membership. CONCLUSIONS: A substantial proportion of individuals hospitalized after mTBI experiences clinically significant persistent symptoms ≤4 years after injury, and those with more severe symptoms have poorer QoL. Further research is required to better understand the factors leading to symptom persistence and poor QoL.