Assessment of Quality of Life 8-Dimension (AQoL-8D): translation, validation, and application in two Dutch trials in patients with epilepsy and schizophrenia

ABSTRACT

Background

To translate and linguistically validate the Assessment of Quality of Life 8-dimensions (AQoL-8D) for use in the Netherlands and to compare the psychometric properties of AQoL-8D with the EuroQol 5-dimensions 5-levels (EQ-5D-5L) in two patient samples.

Methods

AQoL-8D was translated from English into Dutch. The translated AQoL-8D was then administered alongside the EQ-5D-5L at baseline and follow-up of two Dutch randomized controlled trials among patients with epilepsy and schizophrenia. These data were subjected to a post-hoc analysis assessing the psychometric properties of AQol-8D vis-à-vis EQ-5D-5L in terms of known-groups construct validity, responsiveness, and floor/ceiling effects.

Results

In total, 103 epilepsy patients and 99 schizophrenia patients were included in this study. In both datasets, the two instruments discriminated between known-groups, but in schizophrenia, AQoL-8D showed higher responsiveness than EQ-5D-5L, while both instruments showed equal responsiveness in epilepsy. Ceiling effects were only found for EQ-5D-5L in both epilepsy (26.6%) and schizophrenia (6.1%).

Conclusion

Our results have shown that, among other things, AQoL-8D presents better ability to discriminate between known-groups and shows no ceiling effect. Based on our results, we would recommend the use of AQoL-8D in addition to EQ-5D-5L in trials assessing patient’s quality of life in patients with epilepsy or schizophrenia.

KEYWORDS:

• Validity
• EuroQoL-5D
• AQoL-8D
• responsiveness
• quality of life
• utility

Acknowledgments

We would like to thank Reina de Kinderen for her role in the translation of the AQoL-8D to the Dutch version and Angelo Lezzi (Monash University) from the AQoL-group for his support, which facilitated the translation.

Declaration of interest

The authors have no 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. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

One Peer Reviewer has received manuscript or speaker’s fees from Astellas, Dainippon Sumitomo Pharma, Eisai, Eli Lilly, Elsevier Japan, Janssen Pharmaceuticals, Kyowa Yakuhin, Lundbeck, Meiji Seika Pharma, Mitsubishi Tanabe Pharma, Merck Sharp and Dohme, Nihon Medi-Physics, Novartis, Otsuka Pharmaceutical, Shionogi, Shire, Tsumura, Wiley Japan, and Yoshitomi Yakuhin, and research grants from Eisai, Mochida Pharmaceutical, Meiji Seika Pharma, and Shionogi. Peer reviewers in this manuscript have no other relevant financial relationships or otherwise to disclose.

Author contributions

Overall project coordination: SMAA, MH, HJMM. Writing of manuscript: HC, BW. Critical appraisal of manuscript: FS, LAM. All authors have read and approved the manuscript.

Data availability statement

Due to privacy regulations, data will not be made publicly available.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

The ZMILE study was funded by the Netherlands Organization for Health Research and Development (ZonMw) [grant application number 836011018]. The SOFIA study was also funded by ZonMW [grant application number 837001401]. Trial registration numbers: NCT03217955; https://clinicaltrials.gov/ct2/show/NCT03217955 and NTR4484; https://www.trialregister.nl/trial/189.