Health State Valuation in Mild to Moderate Cognitive Impairment: Feasibility of Computer-Based,Direct Patient Utility Assessment

Abstract

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.

Keywords

health state valuation utilities dementia cognitive impairment computer-based techniques reliability. (Med Decis Making 2008;28:220—232)

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