Health-related quality of life in ANCA-associated vasculitis and item generation for a disease-specific patient-reported outcome measure

Abstract

Objective

The antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) are multisystem diseases of the small blood vessels. Patients experience irreversible damage and psychological effects from AAV and its treatment. An international collaboration was created to investigate the impact of AAV on health-related quality of life (HRQoL), and develop a disease-specific patient-reported outcome measure to assess outcomes of importance to patients.

Methods

Patients with AAV from the UK, USA, and Canada were interviewed to identify salient aspects of HRQoL affected by AAV. The study was overseen by a steering committee including four patient research partners. Purposive sampling of interviewees ensured representation of a range of disease manifestations and demographics. Inductive analysis was used to identify themes of importance to patients; these were further confirmed by a free-listing exercise in the US. Individual themes were recast into candidate items, which were scrutinized by patients, piloted through cognitive interviews and received a linguistic and translatability evaluation.

Results

Fifty interviews, conducted to saturation, with patients from the UK, USA, and Canada, identified 55 individual themes of interest within seven broad domains: general health perceptions, impact on function, psychological perceptions, social perceptions, social contact, social role, and symptoms. Individual themes were constructed into >100 candidate questionnaire items, which were then reduced and refined to 35 candidate items.

Conclusion

This is the largest international qualitative analysis of HRQoL in AAV to date, and the results have underpinned the development of 35 candidate items for a disease-specific, patient-reported outcome questionnaire.

Keywords:

• ANCA-associated vasculitis
• quality of life
• patient-reported outcomes
• granuloma-tosis with polyangiitis
• microscopic polyangiitis
• eosinophilic granulomatosis with polyangiitis

Supplementary materials

Table S1 Codebook descriptions of individual themes. Collaborative codebook by core qualitative group using consensus methods

Table S2 Saturation table: domains and subcodes of emergent themes from 50 in-depth individual patient interviews within the US, Canada (CAN), and UK. 0 = theme not present; 1 = theme present

Box S1 Translatability of the questionnaire

• The translatability of the questionnaire refers to whether items can be meaningfully translated into other languages in the future.⁵⁰

• First, a concept elaboration document is produced, which clarifies any ambiguities or nuances within the candidate items and instructions.

• For each item and instruction, concepts and wording are then checked to ensure equivalence between the original and target language, and whether they remain linguistically and culturally appropriate. A sample of different types of languages is tested.

• Arabic (Egypt), Finnish (Finland), German (Germany), Greek (Greece), Russian (Russia), Spanish (Argentina), and Xhosa (South Africa) were the languages tested in this study.

• The questionnaire items were then refined to enable better cultural and linguistic equivalence across future translations, and thereby to improve the measure’s performance when used in international studies.

• A translatability assessment does not go as far as conducting full-scale translation/back-translation process, with testing for validity in another language(s). This is for the future (once the number of questionnaire items has been finalized) and would require a full study for each language. However, the translatability assessment that was undertaken should ensure that future translations are more straightforward and will better facilitate equivalence.

Reference

• ConwayKPatrickDLGauchonTAcquadroCEnhancing crosscultural appropriateness for newly developed patient-reported outcome (PRO) instruments: the use of translatability assessmentPatient Reported Outcomes Newsl201044912
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Acknowledgments

Sponsored by the University of Oxford, the Vasculitis Clinical Research Consortium and the University of Ottawa. With support from the Medical Research Fund, Oxford, the Oxford-shire Health Services Research Committee (Ref 1098), the US National Institute of Arthritis and Musculoskeletal and Skin Diseases (U54 AR057319 and U01 AR51874), the National Center for Research Resources (U54 RR019497), and the Office of Rare Diseases Research. Oxford University Innovation funded the translatability exercise. Additional support received by a Patient-Centred Outcomes Research Institute Pilot Project Grant.

Disclosure

Dr Robson and Professor Luqmani were supported in part by the National Institute for Health Research Musculoskeletal Biomedical Research Unit, Oxford, UK. Dr Robson was supported by a National Institute for Health Research (NIHR) clinical lectureship. Dr Milman was supported by a UCB/Canadian Rheumatology Association/Arthritis Society postgraduate rheumatology fellowship award and a research fellowship from the Department of Medicine at the Ottawa Hospital. The authors report no other conflicts of interest in this work.