Factors Associated With Persisting Symptoms After Concussion in Adults With Mild TBI: A Systematic Review and Meta-Analysis.

Importance: Up to 30% of individuals who sustain a mild traumatic brain injury (mTBI) develop persisting symptoms after concussion (PSAC). Identifying acute risk factors for PSAC can enhance clinical care in adults with concussion. Objective: To evaluate summary odds ratio (OR) estimates for acute factors associated with PSAC in adults with mTBI. Data Sources: For this systematic review and meta-analysis, a systematic search of Ovid MEDLINE, Embase, PsycINFO, CINAHL, SPORTDiscus, and the Cochrane Central Register of Clinical Trials (studies published from 1970 to February 15, 2024) and backward reference searching was performed on February 15, 2024. Search terms were mTBI, concussion, prognostic variables, predictors, and PSAC. Study Selection: Peer-reviewed studies in English that reported clinical factors collected within 1 month (≤28 days) of injury and associated with poor outcome, specifically PSAC, more than 1 month after concussion were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline was followed. Data Extraction and Synthesis: Independent extraction and quality assessment were performed by 2 author reviewers. Study characteristics and ORs were extracted using the Modified Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prognostic Factor Studies. Risk of bias was assessed using the Quality in Prognostic Studies tool. Three-level meta-analytic models examined factors associated with PSAC 1, 3, and 6 months after mTBI. Main Outcomes and Measures: Adjusted OR (AOR) estimates for the association of acute clinical measures with PSAC. Results: Thirty-four studies were reviewed; data were extracted from 15 studies (44.1%) included in the meta-analysis (592 406 adults with concussion; mean age, 29.3 years [range, 16-89 years]; 57.8% male). Acute concentration difficulty was associated with greatest odds of PSAC across all time points (AOR, 3.43 [95% CI, 1.85-6.36]). Medical history of anxiety and/or depression or of sleep disorders (AOR, 2.47 [95% CI, 1.62-3.78]) and clinical signs (loss of consciousness and amnesia; AOR, 1.90 [95% CI, 1.28-2.84]) were associated with increased odds of PSAC across all time points. At 1 month (AOR, 3.12 [95% CI, 1.43-6.82]) and 6 months (AOR, 26.81 [95% CI, 3.42-210.06]), difficulty concentrating was associated with greatest odds of PSAC, while medical history of anxiety and/or depression or of sleep disorders was associated with greatest odds of PSAC at 3 months (AOR, 2.92 [95% CI, 1.39-6.14]). Conclusions and Relevance: In this systematic review and meta-analysis, acute cognitive symptoms, medical history of anxiety and/or depression or of sleep disorders, and the presence of clinical signs (loss of consciousness and amnesia) were the factors associated with greatest odds of PSAC in adults across all time points. The findings suggest that evaluating specific acute symptoms and signs may contribute to the prognosis of PSAC in adults.