Health state valuation in mild to moderate cognitive impairment: feasibility of computer-based, direct patient utility assessment.

BACKGROUND: Most patients with dementia will, at some point, need a proxy health care decision maker. It is unknown whether persons with various degrees of cognitive impairment can reliably report their health-related preferences.
METHODS: The authors performed health state valuations (HSVs) of current and hypothetical future health states on 47 pairs of patients with mild to moderate cognitive impairment and their caregivers using computer-based standard gamble, time tradeoff, and rating scale techniques.
RESULTS: Patients' mean (SD) age was 74.6 (9.3) years. About half of the patients were women (48%), as were most caregivers (73%), who were on average younger (mean age= 66.2 years, SD= 12.2). Most participants were white (83%); 17% were African American. The mean (SD) Mini-Mental State Examination (MMSE) score of patients was 24.2 (4.6) of 30. All caregivers and 77% of patients (36/47) completed all 18 components of the HSV exercise. Patients who completed the HSV exercise were slightly younger (mean age [SD]= 74.1 [8.5] v. 75.9 [11.8]; P = 0.569) and had significantly higher MMSE scores (mean score [SD] = 25.0 [4.3] v. 21.4 [4.4]; P = 0.018). Although MMSE scores below 20 did not preclude the completion of all 18 HSV ratings, being classified as having moderate cognitive impairment was associated with a lower likelihood of completing all scenario ratings (44% v. 82%). Patient and caregiver responses showed good consistency across time and across techniques and were logically consistent.
CONCLUSION: Obtaining HSVs for current and hypothetical health states was feasible for most patients with mild cognitive impairment and many with moderate cognitive impairment. HSV assessments were consistent and reasonable.