Mapping health status measures to a utility measure in a study of nursing home residents with advanced dementia.

BACKGROUND: Nursing home residents with advanced dementia commonly experience burdensome and costly interventions (eg, hospitalization) of questionable clinical benefit. To facilitate cost-effectiveness analyses of these interventions, utility-based measures are needed in order to estimate quality-adjusted outcomes.
METHODS: Nursing home residents with advanced dementia in 22 facilities were followed for 18 months (N=319). Validated health status measures ascertained from nurses at baseline, quarterly, and death (N=1702 assessments) were mapped to the Health Utilities Index Mark 2 [range, 1 (perfect health) to 0 (death); scores below 0 indicate states worse than death]. To assess validity, utility scores were compared between residents who did and did not receive burdensome interventions (parenteral therapy, percutaneous endoscopic gastrostomy tubes, and hospital transfers), residents with and without pneumonia, and residents who did and did not die at the last assessment.
RESULTS: Mean (±SD) Health Utilities Index Mark 2 utility score for the cohort was 0.165±0.060 (range, -0.005 to 0.215). Residents spent an average of 15.5% of their days with utilities <0.10. Lower utility scores were found among residents who received burdensome interventions (0.152±0.067 vs. 0.171±0.056; P=0.0003); had pneumonia (0.147±0.066 vs. 0.170±0.057; P=0.003); and were dying (0.163±0.057 vs. 0.180±0.055; P=0.006).
CONCLUSIONS: It is feasible to map health status measures to utility-based measures for advanced dementia. This work will facilitate future cost-effectiveness analyses aimed at quantifying the cost of interventions relative to quality-based outcomes for patients with this condition.