Validation of the English version of the Health-Related Quality of Life for Drug Abusers (HRQoLDA) test

Development of OSTQOL: A Measure of Quality of Life for Patients in Opioid Substitution Treatment

BACKGROUND

Quality of life (QOL) of patients in opioid substitution treatment (OST) is increasingly being addressed in research. However, no disease- or treatment-specific instrument is available to assess the QOL of this target population. The purpose of this project was to develop the first QOL instrument for OST patients.

METHODS

Focus groups with 60 OST patients were analyzed using thematic analysis to elicit key QOL themes as perceived by patients. Identified themes were developed into items and refined through pilot testing and cognitive debriefing. The resulting 82 items were tested in a large sample of OST patients (n = 577). Principal component analysis with varimax rotation was performed to explore a possible factor structure and reduce the number of items. Psychometric properties were assessed.

RESULTS

Factor analysis revealed 6 subscales accounting for 46.1% of the variance: Personal Development, Mental Distress, Social Contacts, Material Well-being, Opioid Substitution Treatment, and Discrimination. The 38-item instrument demonstrated good to acceptable internal consistency reliability for all subscales (Cronbach's alpha = 0.75-0.88), and good convergent and discriminant validity.

CONCLUSION

The Opioid Substitution Treatment Quality of Life scale (OSTQOL) is a multidimensional instrument with low respondent and administrator burden. A thorough validation is needed to assess its validity.

Psychiatric comorbidity and severity of dependence on substance users: how it impacts on their health-related quality of life?

OBJECTIVE

The aim of this study was to analyze the impact of psychiatric comorbidity and severity of dependence on health-related quality of life (HRQoL).

METHODS

One hundred and ninety-eight substance use disorder (SUD) patients were recruited from an outpatient center that provides treatment for SUD. The International Personality Disorder Examination Screening Questionnaire (IPDE-SQ), Mini International Neuropsychiatric Interview (MINI), Substance Dependence Severity Scale (SDSS) and Health-Related Quality of Life for Drug Abusers test (HRQoLDA test) were administered.

RESULTS

Patients with psychiatric comorbidity evaluated their HRQoL more negatively than patients without psychiatric comorbidity. An analysis of the relationship between severity of dependence and HRQoL scores indicated significant correlations among alcohol-, cocaine-, heroin- and cannabis-dependent patients. According to multivariate analyses, anxiety disorders, mood disorders, severity of dependence on alcohol, cannabis, cocaine, paranoid, borderline and avoidant personality disorders (PDs) were observed to have a major impact on HRQoL.

CONCLUSIONS

SUD (severity of dependence on alcohol, cannabis and cocaine) and other mental disorders (anxiety disorders; mood disorders; paranoid, borderline and avoidant PDs) are involved in the deterioration of the SUD patients' HRQoL. This study demonstrates the need for integrated treatment for SUD patients. Treating only a part of the problem (whether SUD or other mental disorders are present) is insufficient for improving quality of life.

Comparison and concordance of health-related quality of life tests among substance users

Background

In the field of drug and alcohol abuse, health-related quality of life (HRQoL) has been used as an important clinical and research outcome. The aim of this study was to establish score linkages (concordance) among three HRQoL assessment tools: WHOQOL-BREF, DUQOL and HRQOLDA scores, applying a Rasch-based common person equating procedure.

Methods

One hundred and twenty one adults were recruited from inpatient and outpatient treatment facilities in Sydney West Area Health Service. WHOQOL-BREF, DUQOL and HRQOLDA tests were administered. Item parameters were calculated applying Rating Scale Model, a Rasch model.

Results

Fit statistics suggest acceptable goodness-of-fit to the RSM for three instruments. Correlations between HRQOLDA and WHOQOL-BREF and between HRQOLDA and DUQOL scores were 0.719 and 0.613, and the RiU index was 30.4 % and 20.9 %, respectively. All three tests performed adequately for differentiating between individuals whose scores are located at different points along the continuum of the HRQoL construct.

Conclusion

The results demonstrated a higher concordance between the HRQoLDA and WHOQOL-BREF than between the HRQoLDA and the DUQOL. However, it cannot be established unequivocally that the scores of these tools are concordant. In this study, the utility of the application of the Rasch model to provide an empirical benchmark for the selection of measurement tools to be used in the context of health care and research is demonstrated.

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.

Reliability and validity of the Spanish version of the substance dependence severity scale

PURPOSE

The purpose of this study was to estimate the reliability and provide evidence for the validity of the Spanish version of the Substance Dependence Severity Scale (SDSS).

METHODS

A total of 211 substance abusers recruited at a public center that provides treatment for substance-related disorders in an outpatient setting were assessed. Reliability was estimated by Cronbach's α and test-retest. Validity evidence was studied by analyzing the relationships with the European Addiction Severity Index (EuropASI) and Health-Related Quality of Life for Drug Abusers (HRQoLDA).

RESULTS

Adequate reliability coefficients were found for the dependence scales of all addressed substances (α = 0.737 to 0.877; test-retest r = 0.796-0.952). Low internal consistency was found for the abuse scales (α = 0.329-0.694), and adequate test-retest coefficients on alcohol, cocaine and heroin (test-retest r = 0.708-0.902). The reliability of the cannabis abuse scales was inadequate. The SDSS scores showed significant relationships with the EuropASI and HRQoLDA dimensions.

CONCLUSIONS

The psychometric analyses validate the use of the severity of dependence scales. The SDSS abuse scales must be used taking the limitations detected into consideration.

Psychometrics of the Short Form 36 Health Survey version 2 (SF-36v2) and the Quality of Life Scale for Drug Addicts (QOL-DAv2.0) in Chinese mainland patients with methadone maintenance treatment

OBJECTIVE

To test psychometrics of the Short Form 36 Health Survey version 2 (SF-36v2) and the Quality of Life Scale for Drug Addicts (QOL-DAv2.0) in Chinese mainland patients with methadone maintenance treatment (MMT).

METHODS

A total of 1,212 patients were recruited from two MMT clinics in Xi'an, China. Reliability was estimated with Cronbach's α and intra-class correlation (ICC). Convergent and discriminant validity was assessed using multitrait-multimethod correlation matrix. Sensitivity was measured with ANOVA and relative efficiency. Responsiveness was evaluated by pre-post paired-samples t-test and standardized response mean based on the patients' health status changes following 6-month period.

RESULTS

Cronbach's α of the SF-36v2 physical and mental summary components were 0.80 and 0.86 (eight scales range 0.73-0.92) and the QOL-DAv2.0 was 0.96 (four scales range: 0.80-0.93). ICC of the SF-36v2 two components were 0.86 and 0.85 (eight scales range: 0.72-0.87) and the QOL-DAv2.0 was 0.94 (four scales range: 0.88-0.92). Convergent validity was lower between the two instruments (γ <0.70) while discriminant validity was acceptable within each instrument. Sensitivity was satisfied in self-evaluated health status (both instruments) and average daily methadone dose (SF-36v2 physical functioning and vitality scales; QOL-DAv2.0 except psychology scale). Responsiveness was acceptable in the improved health status change (SF-36v2 except vitality scale; QOL-DAv2.0 except psychology and symptoms scales) and deteriorated health status change (SF-36v2 except vitality, social functioning and mental health scales; QOL-DAv2.0 except society scale).

CONCLUSIONS

The SF-36v2 and the QOL-DAv2.0 are valid tools and can be used independently or complementary according to different emphases of health-related quality of life evaluation in patients with MMT.