A brief instrument to measure health-related quality-of-life in patients with bone metastasis: validation of the German version of Bone Metastases Quality-of-Life-10 (BOMET-QoL-10)

Abstract

Aims: This prospective, epidemiologic study was designed to translate the original Spanish Bone Metastases Quality-of-Life-10 (BOMET-QoL-10) questionnaire and undertake a validation of the translated German version of BOMET-QoL-10 in Germany to assess health-related quality-of-life (HRQoL) in patients with bone metastases (BM).

Methods: The translation process included forward and backward translations, and a linguistic validation. Patients aged ≥18 years with histological confirmation of cancer, diagnosed with BM, life expectancy ≥6 months, and fluency in German were eligible for this study (enrolled consecutively in 33 outpatient centers in Germany). Patients were given the German version of BOMET-QoL-10, together with the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire QLQ-C30 and EORTC QLQ-BM22 questionnaires at inclusion, 6 weeks, 3 months, and 6 months after inclusion. A debriefing questionnaire was administered at inclusion to determine patient acceptability and understanding.

Results: Data include 364 patients with BM (median age = 68 years; females = 71.7%). The BOMET-QoL-10 is brief and clear (median completion time = 5 minutes; >90% of patients completed the questionnaire without assistance). The BOMET-QoL-10 forms only one overall scale. All 10 items showed a substantial correlation with the first factor (factor loading, range = 0.58–0.86). BOMET-QoL-10 exhibits high internal consistency and reproducibility (Cronbach’s alpha = 0.91; intra-class correlation coefficient = 0.76). BOMET-QoL-10 showed significant correlations (range = 0.69–0.79) both with EORTC QLQ-C30 and EORTC QLQ-BM22 within the functioning (physical, social, interference) and symptom (fatigue, pain) scales, displayed significant sensitivity to change in EORTC QLQ-BM22 scores, and proved the potential ability to detect change in HRQoL in patients with different disease status.

Limitations: There was a high proportion of females in this study, which might represent a limitation.

Conclusions: The German version of BOMET-QoL-10 is a valid, reliable, brief, and clear instrument able to measure HRQoL in patients with BM.

Keywords:

• German version of BOMET-QoL-10
• bone metastases
• EORTC QLQ-BM22
• EORTC OLQ-C30
• health-related quality-of-life
• prospective epidemiologic study

JEL classification codes:

• I00
• I31

Transparency

Declaration of funding

This project received financial support from Amgen GmbH, Germany.

Declaration of financial/other relationships

CS received an institutional research grant from iOMEDICO (Freiburg, Germany) for statistical analysis. All other authors have disclosed that they have no significant relationships with or financial interests in any commercial companies related to this study or article. JME peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Previous presentations

The data were partly presented at the symposium “Akademie Knochen und Krebs” in Munich, Germany on May 5–6, 2017.

Acknowledgments

The authors thank all patients, physicians and study teams participating in this study. The authors thank Dr Holger Hartmann and PD Dr Jens Hasskarl (former employees at iOMEDICO) for support during project design, Marian Carbonell (PYT Proyectos y Traducciones, Barcelona, Spain) for translation and linguistic validation of the BOMET-QoL-10), Angelika Gerlach (Clinical Trials Unit of the Medical Centre, University of Freiburg) for support during data analysis, Dr Martina Jänicke (iOMEDICO) and Dr med. Leonora Houet (iOMEDICO) for support during project design, data analysis, and critical review of the manuscript, Dr Andrea Kiemen (iOMEDICO) for translation of the project plan from German to English, and Dr Christian Johansson (iOMEDICO) for preparation of the manuscript. This study was designed, managed, analyzed, and sponsored by iOMEDICO. The BOMET-QoL-10 is the intellectual property of Dr Francisco Javier Badia Llach, author of the original validation study. The rights of the German version remain with this author.