Challenges in the cultural adaptation of the German Myeloma Patient Outcome Scale (MyPOS): an outcome measure to support routine symptom assessment in myeloma care

BACKGROUND: Patients with multiple myeloma report more problems with quality of life (QoL) than other haematological malignancies over the course of their incurable illness. The patient-centred Myeloma Patient Outcome Scale (MyPOS) was developed to assess and monitor symptoms and supportive care factors in routine care. Our aim was to translate and culturally adapt the outcome measure to the German context, and to explore its face and content validity. METHODS: Translation and cultural adaptation following established guidelines used an exploratory, sequential mixed method study design. Steps included: (1) forward translation to German; (2) backward translation to English; (3) expert review; (4) focus groups with the target population (patients, family members, healthcare professionals) to achieve conceptual equivalence; (5) cognitive interviews using Tourangeau’s model with think-aloud technique to evaluate comprehension and acceptability; (6) final review. Results were analysed using thematic analysis. RESULTS: Cultural and linguistic differences were noted between the German and English original version. The focus groups (n = 11) and cognitive interviews (n = 9) both highlighted the need for adapting individual items and their answer options to the German healthcare context. Greater individuality regarding need for information with the right to not be informed was elaborated by patients. While the comprehensive nature of the tool was appreciated, item wording regarding satisfaction with healthcare was deemed not appropriate in the German context. Before implementation into routine care, patients’ concerns about keeping their MyPOS data confidential need to be addressed as a barrier, whereas the MyPOS itself was perceived as a facilitator/prompt for a patient-centred discussion of QoL issues. CONCLUSION: With adaptations to answer options and certain items, the German version of the MyPOS can help monitor symptoms and problems afflicting myeloma patients over the course of the disease trajectory. It can help promote a model of comprehensive supportive and patient-centred care for these patients.