RESUMO
BACKGROUND: The measurement of health benefits is a key issue in health economic evaluations. There is very scarce empirical literature exploring the differences of using quality-adjusted life years (QALYs) or disability-adjusted life years (DALYs) as benefit metrics and their potential impact in decision-making. METHODS: Two previously published models delivering outputs in QALYs, were adapted to estimate DALYs: a Markov model for human papilloma virus (HPV) vaccination, and a pneumococcal vaccination deterministic model (PNEUMO). Argentina, Chile, and the United Kingdom studies were used, where local EQ-5D social value weights were available to provide local QALY weights. A primary study with descriptive vignettes was done (n = 73) to obtain EQ-5D data for all health states included in both models. Several scenario analyses were carried-out to evaluate the relative importance of using different metrics (DALYS or QALYs) to estimate health benefits on these economic evaluations. RESULTS: QALY gains were larger than DALYs avoided in all countries for HPV, leading to more favorable decisions using the former. With discounting and age-weighting - scenario with greatest differences in all countries - incremental DALYs avoided represented the 75%, 68%, and 43% of the QALYs gained in Argentina, Chile, and United Kingdom respectively. Differences using QALYs or DALYs were less consistent and sometimes in the opposite direction for PNEUMO. These differences, similar to other widely used assumptions, could directly influence decision-making using usual gross domestic products (GDPs) per capita per DALY or QALY thresholds. CONCLUSION: We did not find evidence that contradicts current practice of many researchers and decision-makers of using QALYs or DALYs interchangeably. Differences attributed to the choice of metric could influence final decisions, but similarly to other frequently used assumptions.
Assuntos
Avaliação da Deficiência , Medicina Preventiva , Avaliação de Programas e Projetos de Saúde/métodos , Anos de Vida Ajustados por Qualidade de Vida , Humanos , Modelos Teóricos , Reprodutibilidade dos TestesRESUMO
OBJECTIVES: Cost-effectiveness analysis has been recommended by national health agencies worldwide. In the United Kingdom, the National Institute of Health and Clinical Excellence supports the use of generic health-related quality of life instruments such as EuroQol EQ-5D when quality-adjusted life-years are used to measure health benefits. Despite the urgent need for appropriate methodologies to improve the use of scarce resources in Latin American countries, little is known about how health is valued. METHODS: A national population survey was conducted in the United States in 2002, based on a sample of 1603 non-Hispanic nonblacks and 1115 Hispanics. Participants provided time trade-off utilities for a subset of 42 EQ-5D health states. Hispanic respondents were grouped according to their language preferences (Spanish or English). Mean utilities were compared for each health state. A random-effects model was used to determine whether real population differences exist after adjusting for sociodemographic characteristics. A population value set for all 243 EQ-5D health states was developed using only the data from Spanish-speaking Hispanics. RESULTS: Mean valuations differed slightly between non-Hispanic nonblacks and English-speaking Hispanics. Spanish-speaking Hispanics, however, tended to give higher valuations than non-Hispanic nonblacks (P < 0.05) corresponding to an average of 0.034 point. A regression model was developed for Spanish-speaking Hispanics with a mean absolute error of 0.031. Values estimated using this model show marked differences when compared with corresponding values estimated using the UK (N3) and US (D1) models. CONCLUSION: The availability of a Hispanic model for EQ-5D valuations represents a significant new option for decision-makers, providing a set of social preference weights for use in Latin American countries that presently lack their own domestic value set.