Background Multiple myeloma is the second most common haematological cancer. It affects quality of life (QOL) due to physical symptoms and psychosocial impairments. Routine assessment of QOL is recommended in the clinical care of myeloma patients, yet no suitable tool exists for this purpose.
Aim To develop and validate an instrument to assess the QOL of people with multiple myeloma that is suitable for use in the clinical setting.
Methods The Myeloma Patient Outcome Scale (MyPOS) was developed in a multi-phased study including qualitative interviews, cognitive interviews, and a cross sectional survey.
Phase 1: Semi-structured qualitative interviews explored the meaning of QOL and views on existing QOL questionnaires from the patients’ perspective. Focus groups of patients and healthcare professionals further explored the meaning of QOL and desired utility of QOL questionnaires in clinical practice. Purposive sampling used throughout except patient focus groups due to feasibility. Thematic analysis identified emergent themes and used to develop a theoretical model of QOL in myeloma.
Phase 2: Above findings used to develop a prototype MyPOS. Cognitive interviews used to evaluate and refine the MyPOS in a purposive sample of myeloma patients.
Phase 3: A national multi-centre survey of myeloma patients to evaluate the psychometric properties of the MyPOS, recruiting from 14 hospital trusts across England. A clinically representative sample sought using consecutive enrolment.
Phase I: 57 participants were recruited across the semi-structured interviews and focus groups. Emergent themes important to QOL were: Biological Status, Treatment Factors, Symptom Status, Activity and Participation, Emotional Status, Support, Expectations, Adaptation and Coping and Spirituality. Most fundamental to QOL were Activity and Participation, Emotional Status and Support. Symptoms had an indirect effect on QOL, only affecting QOL if they impacted more fundamental domains. Health service factors were particularly important, and sexual dysfunction was highlighted by patients and healthcare professionals as a difficult issue to raise in a typical clinical encounter.
Phase 2: The MyPOS was developed as an adaptation of the existing POS questionnaire, taking account of the above findings. Cognitive interviews with 12 participants resulted in refinement of the 33-item preliminary MyPOS to a 30-item tool for field testing.
Phase 3: 380 participants took part in the cross sectional survey. The mean time to complete was 7 minutes 19 seconds with 0.58% missing MyPOS items overall. Internal consistency was high (α=0.89). Principle component analysis suggested three subscales in line with the theoretical model of QOL: Symptoms and Function; Emotional Response; and Healthcare Support. Total MyPOS scores were higher (worse QOL) in those with relapsed or progressive disease compared to newly diagnosed or stable disease (F=II.89, p<0.00I) and were worse in those currently receiving chemotherapy (t=3.42, p<0.001). Scores in the Symptoms and Function subscale were higher (worse QOL) in those with worse ECOG performance status (F=31.33, p<0.001). Good convergent and divergent validity were demonstrated against subscales of the EORTC-QLQ-C30 and MY20 questionnaires.
Conclusions The MyPOS is the first QOL tool designed specifically for use within the clinical care of myeloma patients. It has a theoretical foundation, is acceptable to patients, with good internal consistency, structural validity and construct validity. Further work is needed to evaluate test-re-test reliability, responsiveness to change and minimal important difference, alongside testing of MyPOS’s ability to facilitate a more successful clinical encounter.
|Date of Award||2016|
|Supervisor||Irene Higginson (Supervisor) & Richard Siegert (Supervisor)|