title: A meta-analysis of neuropsychological outcome after mild traumatic brain injury: re-analyses and reconsiderations of Binder et al. (1997), Frencham et al. (2005), and Pertab et al. (2009).
abstract: The meta-analytic findings of Binder et al. (1997) and Frencham et al. (2005) showed that the neuropsychological effect of mild traumatic brain injury (mTBI) was negligible in adults by 3 months post injury. Pertab et al. (2009) reported that verbal paired associates, coding tasks, and digit span yielded significant differences between mTBI and control groups. We re-analyzed data from the 25 studies used in the prior meta-analyses, correcting statistical and methodological limitations of previous efforts, and analyzed the chronicity data by discrete epochs. Three months post injury the effect size of -0.07 was not statistically different from zero and similar to that which has been found in several other meta-analyses (Belanger et al., 2005; Schretlen & Shapiro, 2003). The effect size 7 days post injury was -0.39. The effect of mTBI immediately post injury was largest on Verbal and Visual Memory domains. However, 3 months post injury all domains improved to show non-significant effect sizes. These findings indicate that mTBI has an initial small effect on neuropsychological functioning that dissipates quickly. The evidence of recovery in the present meta-analysis is consistent with previous conclusions of both Binder et al. and Frencham et al. Our findings may not apply to people with a history of multiple concussions or complicated mTBIs.
authors.affiliation: University of South Alabama, Mobile, AL 36688-0002, USA. mrohling@usouthal.edu
authors.forename: Martin L
authors.initials: ML
authors.lastname: Rohling
authors.forename: Laurence M
authors.initials: LM
authors.lastname: Binder
authors.forename: George J
authors.initials: GJ
authors.lastname: Demakis
authors.forename: Glenn J
authors.initials: GJ
authors.lastname: Larrabee
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Ploetz
authors.forename: Jennifer
authors.initials: J
authors.lastname: Langhinrichsen-Rohling
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000150:complications*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000209:etiology; D009483:Neuropsychological Tests; D012044:Regression Analysis; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult