Comorbidity-Related Functional Implications In Traumatic Brain Injury: A Systematic Review

Abstract

<h3>Objective(s)</h3> To systematically identify and synthesize existing evidence on comorbidity-related implications in adults with TBI. <h3>Data Sources</h3> Systematic searches were conducted in Medline, Cochrane Central Register of Controlled Trials, Embase, and PsycINFO, from May 1997 to September 2020. <h3>Study Selection</h3> Peer-reviewed English journal articles on prospective and retrospective longitudinal studies focusing on comorbidity in relation to cognitive or physical functioning in adult patients with TBI, were considered eligible. Letters to editors, reviews without data, case reports, conference abstracts, articles without primary data, studies that focus on therapeutic interventions, and theses, were excluded. Three researchers independently screened and assessed articles for fulfillment of the inclusion criteria. <h3>Data Extraction</h3> Quality assessment followed the Quality in Prognosis Studies tool and the Scottish Intercollegiate Guidelines Network methodology recommendations. <h3>Data Synthesis</h3> A total of 15,278 citations were abstracted from databases searched. Twenty-two studies of moderate quality discussed effects of comorbidities on functional outcomes in patients with TBI. The extracted data were synthesized through tabulation and qualitative description. Cognitive and physical functioning were negatively affected by a wide range of studied comorbidities, including systemic medical diseases, psychiatric conditions, and neurological disorders. The effect of comorbidity, even within the same categories of comorbidity and functional outcome, differed across studies. Severity of TBI, sex/gender, and age were important factors in the relationship. Due to methodological heterogeneity between studies, meta-analyses were not performed. <h3>Conclusions</h3> This systematic review highlights the adverse effect of comorbidities on functional outcome in patients with TBI and enhances our understanding of their impact for both patients with TBI and clinicians who treat and rehabilitate these patients. It is essential to be aware of these comorbidity-related functional implications. PROSPERO registration (CRD 42017070033). <h3>Author(s) Disclosures</h3> The authors have no conflicts of interest to declare.