We studied health utilities in patients with type 1 diabetes to understand potential differences in health utilities as function of age, type of respondent (self-report vs. proxy-report), and method of assessment (direct versus indirect).
Research Design and Methods
We elicited self-reported health utilities for adults (n=213) and children (n=238) with type 1 diabetes, and by parent proxy-report (n=223) for overall quality of life (Health Utilities Index [HUI] Mark 3 and experienced time-tradeoff [TTO] questions) and hypothetical complication states (TTO questions).
Mean health utilities for overall quality of life (QOL) ranged from 0.81 to 0.91. Children had significantly higher overall QOL compared with adults (0.89 vs. 0.85, p<0.01) by HUI, but had no significant difference in QOL by TTO. There were no significant differences in QOL between child self-report and parent proxy-report. Utilities were higher for HUI vs. TTO for parent proxy-report (p<0.01) but not for adult or child self-report. Utilities for hypothetical complication states were lower than for current QOL. Values were lower for stroke (0.34-0.53), end stage renal disease (0.47-0.55), and blindness (0.52-0.69) than for amputation (0.73-0.82) and angina (0.74-0.80). Complication utilities for parent proxy-report were higher compared with adult self-report for most hypothetical complication states.
Individuals with type 1 diabetes with few complications report a relatively high QOL; however, future end stage complications are rated as having a significant impact on QOL. Differences in utilities by age, self-report vs. proxy-report, and method raise important questions about whose utilities should be used in economic analyses.