A polytomous Rasch analysis of the English version of Health-Related Quality of Life for Drug Abusers Test

The specific aim of this study was to analyze the psychometric properties of the English version of the Health-Related Quality of Life for Drug Abusers Test (HRQoLDA Test) applying the Rasch model, and emphasizing fit between empirical data and theoretical Rasch model assumptions; item(s) category probability curve; and precision in terms of information function. In this study, the authors present the results of the translation and adaptation of the original Spanish version to English, as applied to a sample of substance users in Australia. The authors evaluated 121 adults recruited from inpatient and outpatient treatment facilities in Sydney, Australia. The Rating Scale Model was used in the psychometric analysis of the English version of the HRQoLDA Test. The items and persons revealed a fit between the reported data and the model. It was also demonstrated that respondents did not discriminate among the five response categories, which led to a reduction to three response categories. The adaptation of the TECVASP to the English language, renamed the HRQoLDA test, as developed with an Australian sample revealed adequate psychometric properties.