title: Medical decision-making capacity in cognitively impaired Parkinson's disease patients without dementia.
abstract: Little is currently known about the higher order functional skills of patients with Parkinson disease and cognitive impairment. Medical decision-making capacity (MDC) was assessed in patients with Parkinson's disease (PD) with cognitive impairment and dementia. Participants were 16 patients with PD and cognitive impairment without dementia (PD-CIND), 16 patients with PD dementia (PDD), and 22 healthy older adults. All participants were administered the Capacity to Consent to Treatment Instrument (CCTI), a standardized capacity instrument assessing MDC under five different consent standards. Parametric and nonparametric statistical analyses were utilized to examine capacity performance on the consent standards. In addition, capacity outcomes (capable, marginally capable, or incapable outcomes) on the standards were identified for the two patient groups. Relative to controls, PD-CIND patients demonstrated significant impairment on the understanding treatment consent standard, clinically the most stringent CCTI standard. Relative to controls and PD-CIND patients, PDD patients were impaired on the three clinical standards of understanding, reasoning, and appreciation. The findings suggest that impairment in decisional capacity is already present in cognitively impaired patients with PD without dementia and increases as these patients develop dementia. Clinicians and researchers should carefully assess decisional capacity in all patients with PD with cognitive impairment.
authors.affiliation: Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0017, USA.
authors.forename: Roy C
authors.initials: RC
authors.lastname: Martin
authors.forename: Ozioma C
authors.initials: OC
authors.lastname: Okonkwo
authors.forename: Joni
authors.initials: J
authors.lastname: Hill
authors.forename: H Randall
authors.initials: HR
authors.lastname: Griffith
authors.forename: Kristen
authors.initials: K
authors.lastname: Triebel
authors.forename: Alfred
authors.initials: A
authors.lastname: Bartolucci
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Nicholas
authors.forename: Ray L
authors.initials: RL
authors.lastname: Watts
authors.forename: Natividad
authors.initials: N
authors.lastname: Stover
authors.forename: Lindy E
authors.initials: LE
authors.lastname: Harrell
authors.forename: David
authors.initials: D
authors.lastname: Clark
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Marson