Researchers developed a new questionnaire that assesses a patient’s perspective on how anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, or AAV, impacts health-related quality of life.
While the questionnaire should be shorter and validity testing is needed, this patient-reported measure has already helped clinicians understand which health-related outcomes matter most to AAV patients.
The study, “Health-related quality of life in ANCA-associated vasculitis and item generation for a disease-specific patient-reported outcome measure,” appeared in the journal Patient Related Outcome Measures.
AAV is a group of autoimmune diseases characterized by the inflammation and destruction of small vessels. The disease has three overlapping subtypes: granulomatosis with polyangiitis, microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis.
While the disease’s impact on health-related quality of life is well-known, researchers and physicians still need an in-depth assessment of patient perspectives on the full effect of the disease on their quality of life.
Clinical studies of AAV usually focus on assessments that are relevant to physicians, which differ from the perceptions reported by patients. For example, patients value fatigue over dialysis or oxygen dependence. Therefore, clinical trials of AAV treatments should include both physician- and patient-focused outcomes.
In this regard, the Outcome Measurement in Rheumatology (OMER-ACT) Vasculitis Working Group has stressed the importance of developing an AAV-specific patient-reported outcome (PRO) instrument. This was the goal of an international collaboration involving researchers from the U.S., the U.K., and Canada.
The partnership follows guidelines from the U.S. Food and Drug Administration (FDA), which stresses that the creation of a PRO instrument should start with a qualitative analysis.
Investigators interviewed 24 men and 26 women with AAV. They sampled patients with all three disease phenotypes and with different age ranges, duration of disease, and organ involvement to ensure an adequate representation of AAV was included.
The results revealed 55 individual themes of interest to AAV patients, which were grouped in seven broad domains: general health perceptions; symptoms; impact on function, described as the amount of difficulty completing a specific task; psychological perceptions; social perceptions; social contact; and social roles. This led to the development of 105 candidate questionnaire items, which were then refined to 35 items.
The final list involved themes previously reported in quantitative studies, such as fatigue, anxiety, depression, or employment, as well as newer themes, including difficulty in making plans, the investigators said.
“The item generation for a novel, disease-specific PRO measure is underpinned by this qualitative research, which should ensure that the final candidate items have good face validity within each country,” researchers wrote.
Among the study’s strengths, the scientists mentioned the high level of patient involvement and its ongoing critical review on OMER-ACT workshops.
Although the 35-item questionnaire still needs to be shortened to minimize responder burden and increase feasibility, the study supports that “a combined approach of using disease-specific and generic PRO measures may, therefore, be the optimum way of comprehensively measuring HRQoL in AAV,” the investigators concluded.