Measuring health-related quality of life in patients treated for substance dependence: differences among instruments and methods of eliciting preferences

ABSTRACT

Background

Measuring the health-related quality of life is an essential estimation in cost–utility studies. In this research, we provide new evidence about comparing utility scores – in the field of substance dependence. Although the main objective is to compare the EQ-5D-5L and SF-6D with paired gamble, evidence about the SF-6D with standard gamble is also provided.

Methods

Ninety-four patients with substance dependence were recruited; the SF-6D and the EQ-5D-5L were administered at the beginning of treatment and 6 months thereafter. Differences in treatment effect were estimated by comparing utility gains. All analyses were reproduced for two subgroups of severity.

Results

Both the baseline scores and the treatment effect are sensitive to the instrument used. For severe states, the SF-6D with paired gamble (SF-6D with standard gamble) estimates the lowest (highest) utility. With regard to the impact of treatment, the EQ-5D-5L and SF-6D with paired gamble estimate strongly similar effects for severe states (and both estimate greater effects than does the SF-6D with standard gamble).

Conclusions

These findings have implications for cost–utility analyses. The incremental cost-utility ratio of treatments intended for severe states is barely sensitive to the choice of EQ-5D-5L or SF-6D with paired gamble.

KEYWORDS:

• EQ-5D-5L
• SF-6D
• paired gamble
• standard gamble
• substance dependence
• quality of life

Acnowledgements

The authors are grateful to participants at the various centers (Aclad Alborada Vigo, UAD Ribeira, CTA Chiclana, CTA Algeciras, and Fundación Proyecto Hombre Navarra). The authors especially thank Jesús Morán and Jesús Terradillos for their collaboration in recruiting patients and conducting the survey.

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewers disclosure

Peer reviewers on this manuscript have no relevant financial relationships or otherwise to disclose.

Author contribution

All co-authors played a role in designing and implementing the research, analyzing the results and writing the manuscript.

Ethical approval

All procedures performed in this study were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in this study.

Additional information

Funding

This study was funded by the Spanish Ministry of Health, Social Services and Equality [Grant no. 2013I027] and by the Spanish Ministry of Science, Innovation and Universities and FEDER [Grant RTI2018-099403-B-I00].