Measurement of clinical-effect: utility.

The utility approach to assessing health-related quality of life is the most widely used technique for assessing preferences for health outcomes in the economic evaluation of health care. The scale for utility scores assigns a value of 1.0 to perfect health and 0.0 to death. The utility scores are employed to weigh time spent in each health state to estimate quality-adjusted life years (QALYs) gained, which is used as the denominator in cost-utility analysis and cost-effectiveness analysis. Utility scores are obtained through direct assessments using techniques such as standard gamble (SG), time-trade off (TTO), and visual analog scale (VAS), or by using multi-attribute systems such as the Health Utilities Index (HUI) or EuroQol (EQ-5D). According to international HE guidelines, the most preferred utility methods are SG and TTO, followed by EQ-5D, VAS and HUI, respectively In Thailand, the EQ-5D is the most recommended utility method because it has acceptable feasibility and validity.

Psychometric properties of WHOQOL-BREF-THAI in patients with HIV/AIDS.

OBJECTIVE: To assess reliability and validity of the Thai abbreviated version of World Health Organization quality of life (WHOQOL-BREF-THAI) in HIV/AIDS patients. MATERIAL AND METHOD: The present study is descriptive research. Data were purposefully collected from 120 HIV/AIDS outpatients at Bamrasnaradura Infectious Disease Institute, Thailand, during September-December 2004. RESULTS: Cronbach's alpha ranged from 0.61 to 0.81 across domains. Exploratory factor analysis identified four major domains: physical, psychological, social and environmental domains, corresponding to the four WHOQOL-BREF domains. The four domain scores correlated positively with general health satisfaction and overall quality of life questions (all p < 0.01 except general health & social domain p < 0.05), and correlated negatively with the frequency and severity of HIV symptoms (all p < 0.01). The four domain scores discriminated between patients with higher and lower frequency and severity of HIV symptoms (all p < 0.01). CONCLUSION: The present study shows that WHOQOL-BREF THAI can be a good generic health-related quality of life instrument in HIV/AIDS patients.