Factors influencing patient-reported outcomes in ANCA-associated vasculitis: correlates of the Patient Global Assessment

Background: Patient-reported outcomes (PROs) are currently poorly integrated in the clinical evaluation of disease activity in patients with ANCA-associated vasculitis (AAV).

Objectives: To assess the distribution of the Patient Global Assessment (PtGA) in patients with AAV in stable remission, and to identify correlates of PtGA; to assess the discordance between PtGA score and Physician Global Assessment (PhGA).

Methods: Patients with a diagnosis of AAV in stable remission (BVAS=0) and with a Physician Global Assessment (PhGA)=0 were included. The following PROs on a 0-100 visual analogue scale (VAS) were assessed: PtGA, fatigue, pain, general health, sleep quality, and chronic damage according to the patient's opinion. The Cragg Hurdle model was used to assess the predictors of PtGA.

Results: 65 patients were included, female 57%, mean age 61±12 years. Median disease duration 6 years (IQR 3-12). Vasculitis damage index (VDI) was 4.4±2.3. Despite having been classified as being in remission, PtGA was elevated in 37% of patients. The PtGA was not associated with older age, comorbidities, educational level, the type of AAV diagnosis, number of organ-systems involved, previous relapses, disease duration, nor higher VDI. Female sex was significantly associated with PtGA: 51% of female patients reported an elevated PtGA compared to 18% of males (p=0.009). PtGA significantly correlated with all the other assessed PROs. Pain and fatigue were the main determinants of an elevated PtGA.

Conclusions: A significant proportion of patients with AAV considered to be in remission by the physician still declares to have persistent aspects of uncontrolled disease. PtGA is significantly influenced by pain and fatigue, which should receive more attention in the future assessment of patients with AAV.