title: Cognitive models of medical decision-making capacity in patients with mild cognitive impairment.
abstract: This study investigated cognitive predictors of medical decision-making capacity (MDC) in patients with amnestic mild cognitive impairment (MCI). A total of 56 healthy controls, 60 patients with MCI, and 31 patients with mild Alzheimer's disease (AD) were administered the Capacity to Consent to Treatment Instrument (CCTI) and a neuropsychological test battery. The CCTI assesses MDC across four established treatment consent standards--S1 (expressing choice), S3 (appreciation), S4 (reasoning), and S5 (understanding)--and one experimental standard [S2] (reasonable choice). Scores on neuropsychological measures were correlated with scores on each CCTI standard. Significant bivariate correlates were subsequently entered into stepwise regression analyses to identity group-specific multivariable predictors of MDC across CCTI standards. Different multivariable cognitive models emerged across groups and consent standards. For the MCI group, measures of short-term verbal memory were key predictors of MDC for each of the three clinically relevant standards (S3, S4, and S5). Secondary predictors were measures of executive function. In contrast, in the mild AD group, measures tapping executive function and processing speed were primary predictors of S3, S4, and S5. MDC in patients with MCI is supported primarily by short-term verbal memory. The findings demonstrate the impact of amnestic deficits on MDC in patients with MCI.
authors.affiliation: Department of Psychology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0017, USA.
authors.forename: O C
authors.initials: OC
authors.lastname: Okonkwo
authors.forename: H R
authors.initials: HR
authors.lastname: Griffith
authors.forename: K
authors.initials: K
authors.lastname: Belue
authors.forename: S
authors.initials: S
authors.lastname: Lanza
authors.forename: E Y
authors.initials: EY
authors.lastname: Zamrini
authors.forename: L E
authors.initials: LE
authors.lastname: Harrell
authors.forename: J C
authors.initials: JC
authors.lastname: Brockington
authors.forename: D
authors.initials: D
authors.lastname: Clark
authors.forename: R
authors.initials: R
authors.lastname: Raman
authors.forename: D C
authors.initials: DC
authors.lastname: Marson
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology; D001288:Attention / Q000502:physiology; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000503:physiopathology*; D003657:Decision Making / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D016743:Mental Competency / Q000523:psychology*; D008875:Middle Aged; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D012016:Reference Values; D014705:Verbal Behavior / Q000502:physiology; D014796:Visual Perception / Q000502:physiology