Search

Purpose: Previous studies using the WHOQOL measures have demonstrated that the relationship between individual items and the underlying quality of life (QoL) construct may differ between cultures. If unaccounted for, these differing relationships can lead to measurement bias which, in turn, can undermine the reliability of results.Methods: We used item response theory (IRT) to assess differential item functioning (DIF) in WHOQOL data from diverse language versions collected in UK, Zimbabwe, Russia, and India (total N = 1332). Data were fitted to the partial credit 'Rasch' model. We used four item banks previously derived from the WHOQOL-100 measure, which provided excellent measurement for physical, psychological, social, and environmental quality of life domains (40 items overall). Cross-cultural differential item functioning was assessed using analysis of variance for item residuals and post hoc Tukey tests. Simulated computer-adaptive tests (CATs) were conducted to assess the efficiency and precision of the four items banks.Results: Splitting item parameters by DIF results in four linked item banks without DIF or other breaches of IRT model assumptions. Simulated CATs were more precise and efficient than longer paper-based alternatives.Discussion: Assessing differential item functioning using item response theory can identify measurement invariance between cultures which, if uncontrolled, may undermine accurate comparisons in computer-adaptive testing assessments of QoL. We demonstrate how compensating for DIF using item anchoring allowed data from all four countries to be compared on a common metric, thus facilitating assessments which were both sensitive to cultural nuance and comparable between countries. [ABSTRACT FROM AUTHOR]

Intervention programs aimed at preventing tobacco use among youth have been shown to be effective in curbing tobacco use onset and progression. However, the effects of even very successful tobacco prevention programs may not always impress policy-makers and lay audiences. Economic analysis potentially strengthens the case. In this paper, we evaluate the cost-effectiveness of a youth tobacco use prevention program which has been translated and implemented in India, a developing country. Although programs like these are inexpensive to implement in the USA, they are even less expensive in India due to low labor costs. Our results show that the costs per quality-adjusted life-year added, due to averted smoking, was $2057, even without including averted medical costs. If we ignore student time, cost-effectiveness improves by roughly 10%. To put the cost-effectiveness of this smoking prevention program into context, it is over 24 times more cost-effective than dialysis in the USA, which costs $50 000 for a life-year. [ABSTRACT FROM PUBLISHER]