Development of a Specific Health-Related Quality of Life Test in Drug Abusers Using the Rasch Rating Scale Model

Abstract

A test has recently been designed for the measurement of health-related quality of life in drug abusers (Health-Related Quality of Life for Drug Abusers Test – HRQOLDA Test) based on the bi-axial concept of addiction. The aim of this work is to find out the metric properties of the test by applying the polytomous Rasch Rating Scale Model (RSM). The HRQOLDA Test was given to a sample of 358 drug abusers who began treatment in a Therapeutic Community. The Rating Scale Model (RSM) and the WINSTEPS programme were used for the analysis of its metric properties. The results shown here are an overall fit of data to the model. The items are adequately distributed over the HRQOL continuum. The response categories appear to be in order except for the category ‘a little’. The test region which measures most accurately, and is most informative, is in the middle of the continuum. The test properties studied confirm the adequacy of the RSM for accurate measurement of HRQOL in drug abusers, providing a test for measuring this specific construct in this population.

Quality of Life in Therapeutic Communities for Addictions: A Positive Search for Wellbeing and Happiness

“…However, up until now, only a limited number of studies have specifically addressed QoL in therapeutic communities for addiction (e.g., Fisher and Roche, 2013;GonzalezSaiz et al 2009 andGuimares et al 2014;Johnson et al 2012;Lozano Rojas et al 2009;Snyder et al 2015;Vanderplasschen et al 2013). …”

Validation of the English Version of the Health-Related Quality of Life for Drug Abusers (HRQoLDA) Test

“…2). All factor loadings are shown in table 2 (factor loadings of the original Spanish version were also reported for comparative purposes) [20]. With the exception of items 19 and 20, which presented reduced factor loadings, all additional items presented satisfactory loading values.…”

“…The HRQoLDA is a quality of life assessment tool specific for drug abuse [20]. It assesses the physical and psychosocial aspects of life through 20 five-choice items in a Likert type scale, with choices being designated 1–5 points.…”

“…On the negative items: ‘not at all’ (1 point), ‘a little’ (2 points), ‘sometimes’ (3 points), ‘quite a bit’ (4 points), and ‘a lot’ (5 points). The sum of the 20 scores represents QoL, such that the higher the score, the better the QoL [20]. …”

“…In contrast to general QoL measures, which are structured around domains of similar importance, QoL tools specifically designed for substance use measurement allow for a specific selection of life areas that are most salient for substance users [19]. Such tools include the Injection Drug User QoL Scale (IDUQoL), an instrument utilized in Canada that evaluates changes of QoL in injection drug users, and the Medical Outcome Study-HIV Health Survey (MOS-HIV), used to assess substance use and QoL among patients infected with HIV [19,20]. …”