Validity and reliability of the QLQ-MY20 module for assessing the health-related quality of life in Brazilians with multiple myeloma

Abstract

Purpose

Multiple myeloma (MM) is a rare but treatable hematological cancer, which makes the health-related quality of life (HRQoL) an important patient-report outcome measure in clinical studies. The Quality of Life Questionnaire Multiple Myeloma Module (QLQ-MY20) was developed by the European Organization for Research and Treatment of Cancer (EORTC) to measure HRQoL in people with MM. However, the Brazilian Portuguese version of QLQ-MY20 has not yet been validated for Brazil. This study aimed to evaluate the validity and reliability of the instrument for application in Brazilian patients with MM.

Methods

This is a cross-sectional methodological study with patients seen in health services in Belo Horizonte, Brazil. The variables were collected through face-to-face interviews with the QLQ-MY20 instrument and complemented with data from medical records. Content validity analyses (content validity coefficient [CVC]; correctness ratio), convergent and divergent validity (Spearman’s correlation coefficient [CC]), internal consistency, and temporal reproducibility (test–retest; intraclass correlation coefficient [ICC]) were performed.

Results

225 patients were included and 71.1% were older than 60. The analysis of the judging committee showed adequate content validity. We observed mainly a good internal consistency of the items and good discrimination power in the convergent and divergent validity. High ICC values were observed through the test–retest, and there was no difference in the scores between the two moments, which shows good temporal stability of the instrument.

Conclusion

The study allowed us to conclude that the Brazilian version of the QLQ-MY20 module is valid and reliable, and thus suitable for application in Brazilians living with MM.

Keywords:

• Health-related quality of life
• QLQ-MY20
• validity
• reliability
• multiple myeloma
• patient-report outcome measure

Transparency

Declaration of funding

This paper was not funded.

Declaration of financial/other relationships

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

Author contributions

JSM, CAMP, LPS, PLMD, AMMR and RMMS contributed substantially to the conception and design of the work. JSM, LPS, PLMD and NLC contributed substantially to the data collection. JSM, CAMP and AMMR performed the analysis and interpretation of data. IAR revised the manuscript critically for important intellectual content. All the authors contributed substantially to the draft of the manuscript. The final version of the manuscript was approved by all the authors.

Acknowledgements

We are grateful to the staff of the public hospitals and to the “Clínica Hematológica” for their availability and collaboration. We thank Capes (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) for the master’s fellowship awarded to JSM.

Data availability statement

Research data are not shared. The data are not publicly available due to privacy or ethical restrictions.

Notes

i SPSS is a registered trademark of IBM Corporation, Armonk, New York, NY, USA.

ii SAS is a registered trademark of SAS Institute Inc, Cary, NC, USA.