Association between preinjury health factors and outcomes after minor to moderate motor vehicle crash injuries: a systematic review and meta-analysis

Around 50% of individuals with minor to moderate motor vehicle crash injuries experience adverse health outcomes up to 2 years postinjury, yet the associations between preinjury health on postinjury outcomes are unclear. Understanding these associations could support risk stratification and inform targeted interventions for individuals at risk of poor postinjury outcomes. In this review, we synthesized the available evidence on these associations. We identified relevant observational studies using an electronic search of 6 databases. We assessed risk of bias using Quality in Prognosis Studies, conducted random-effects meta-analyses where possible, and provided a narrative synthesis where meta-analysis was not possible. We included 58 articles (32 study populations, n = 27,167) and conducted meta-analyses on data from 13 studies (n = 7829). Meta-analyses and narrative syntheses showed that preinjury pain doubled the odds of acute/subacute (adjusted odds ratio 2.02 [95% confidence interval 1.21-3.36]) and chronic (adjusted odds ratio 2.28 [95% confidence interval 1.52-3.43]) postinjury pain. Preinjury mental health conditions consistently predicted later mental health problems. Limited evidence indicated that preinjury pain was associated with subsequent mental health problems and perceived poor recovery, whereas preinjury mental health conditions were associated with later pain, physical disability, and lower quality of life. Across outcomes, associations with preinjury general health were absent or inconsistent; evidence for preinjury physical health, sleep, and history of injury was sparse. The certainty of evidence ranged from very low to moderate. In conclusion, evidence generally suggests that preinjury physical and psychological vulnerabilities may contribute to poor postinjury outcomes. Preinjury pain is the most robust predictor of postinjury pain, and preinjury mental health conditions may predispose individuals to later mental health problems.