A new patient-reported outcome (PRO) questionnaire for ANCA-associated vasculitis (AAV) is a reliable and feasible tool able to distinguish between different disease states, according to a new study.
The study, “Validation of the ANCA-associated vasculitis patient-reported outcomes (AAV-PRO) questionnaire,” appeared in the journal Annals of the Rheumatic Disease.
Although recent treatments improved the health and survival of AAV patients, the risk of relapse in these patients is still 35 percent over five years. This is associated with a significant psychosocial impact and persistent disease activity, as well as damaging and persistent exposure to toxic treatments.
AAV patients have higher rates of depression and anxiety than healthy subjects. Work disability, pain, and fatigue are also problems. However, patients and clinicians often have differing opinions on the relative importance of these different consequences of the disease.
An international steering committee made up of patient partners, methodologists, statisticians, and clinicians has been working with the U.S. Food and Drug Administration to develop an AAV-specific PRO that better captures patients’ views and helps assess the impact of new treatments.
The group used a three-step strategy, which first resulted in a 35-item candidate AAV-PRO questionnaire. The second stage involved a large-scale survey of AAV patients in the U.K. and U.S. to study the scale structure of the AAV-PRO, and then the third stage was evaluation and validation of the AAV-PRO’s measurement properties. This study reports the results of stages two and three.
Participants completed the 35-item candidate questionnaire at the beginning of the study and after three months. According to the investigators, this short follow-up limited the evaluation of responsiveness and minimally important change. The studied group included 626 participants with AAV, with more than 25 percent reporting active disease.
Analysis of the scale structure supported a final 29-item measure with six domains: organ-specific symptoms, systemic symptoms, treatment side effects, social and emotional impact, concerns about the future, and physical function.
“The identified domains offer a comprehensive profile of the impact of AAV on patients’ everyday life and were felt by the patient partners to represent ‘what AAV was to them,’ ” the investigators wrote.
Results revealed that mean domain scores were higher, meaning they were worse, for participants reporting active disease versus those reporting remission. Women scored higher on all six subscales. Patients who reported their condition as “much better” had small changes in AAV-PRO scores.
EQ-5D-5L, a standardized measure of health-related quality of life, helped establish the questionnaire’s validity in U.K. patients. U.S. patients completed a test-retest exercise of reliability.
Of note, the data revealed that disease activity, rather than duration of disease, is a crucial correlation to AAV-PRO scores.
“The AAV-PRO, a new disease-specific PRO measure for AAV, has good face and construct validity, is reliable, feasible and discriminates among disease state,” the researchers wrote.
“The AAV-PRO is ready for inclusion within clinical trials and research studies as part of its ongoing validation and exploration of its measurement properties within different populations,” they said.