John Brazier — Page 2 | PubMed Health

PubMed2002

The estimation of a preference-based measure of health from the SF-36.

This paper reports on the findings of a study to derive a preference-based measure of health from the SF-36 for use in economic evaluation. The SF-36 was revised into a six-dimensional health state classification called the SF-6D. A sample of 249 states defined by the SF-6D have been valued by a representative sample of 611 members of the UK general population, using standard gamble. Models are estimated for predicting health state valuations for all 18,000 states defined by the SF-6D. The econometric modelling had to cope with the hierarchical nature of the data and its skewed distribution. The recommended models have produced significant coefficients for levels of the SF-6D, which are robust across model specification. However, there are concerns with some inconsistent estimates and over prediction of the value of the poorest health states. These problems must be weighed against the rich descriptive ability of the SF-6D, and the potential application of these models to existing and future SF-36 data set.

Activities of Daily Living↗

PubMedDate not supplied

Comparison of health state utilities using community and patient preference weights derived from a survey of patients with HIV/AIDS.

OBJECTIVES: The authors compare health state utilities derived from a national survey of patients with HIV/AIDS to represent community-based preferences with utilities derived from the same survey representing patient preferences; explore the relationships between these utilities and the dimensions of the SF-6D health state classification; and examine the implications of differences in the source of utilities for a cost-effectiveness analysis of early treatment of patients with HIV/AIDS. METHODS: The authors derived community-based standard gamble (SG) utilities using an algorithm developed for the SF-6D health state classification system. The authors derived patient SG utilities from HIV/AIDS patient rating scale self-assessments using a power transformation. Data were from the HIV Cost and Services Utilization Study, a probability sample of 2864 HIV-infected adults receiving care in the United States in 1996. RESULTS: Patient SG utilities were higher than community SG utilities by 4% to 9% (0.979 vs. 0.937, 0.910 vs. 0.841, and 0.845 vs. 0.778; P < 0.001 for all comparisons). In regression analyses, patient SG utilities were less influenced by physical functioning, pain, and mental health dimensions of the SF-6D. The base case results of a cost-effectiveness analysis comparing early antiretroviral therapy to deferred therapy were unaffected by the choice between community ($20,100 per quality-adjusted life year) and patient ($18,400 per quality-adjusted life year) perspectives. The impact of the choice of utilities remained small in sensitivity analyses that varied the influence of treatment side effects on utilities and the initial symptom status of patients. CONCLUSION: There are differences between community and patient utilities for HIV/AIDS health states, although even when treatment side effects are important, these differences may not affect cost-effectiveness ratios.

Acquired Immunodeficiency Syndrome↗