1 research outputs found
Psychometric properties of the Spanish version of the once-daily Urticaria Activity Score (UAS) in patients with chronic spontaneous urticaria managed in clinical practice (the EVALUAS study)
Background: The daily diary Urticaria Activity Score (UAS) and its weekly score (UAS7) are widely used to assess
signs and symptoms in patients with chronic spontaneous urticaria (CSU). The objective of this study was to assess
the psychometric properties of a Spanish version of the once-daily UAS.
Methods: Observational study in patients ≥18 years old receiving usual care for CSU (daily or almost daily occurrence
of generalized hives or angioedema for ≥6 weeks). Patients were included consecutively and completed the UAS, EQ5D, and the Chronic Urticaria Quality of Life scale (CU-Q2oL) at two study visits 6 weeks apart. On each occasion, the
UAS was completed once-daily for 7 consecutive days to be able to calculate the UAS7 score. Psychometric properties
of reliability, construct validity, and responsiveness were assessed. The Minimal Important Difference (MID) was
estimated for the UAS7 using anchor- and distribution-based approaches.
Results: Data from 166 patients was available for analysis (mean age 49 years, 65.7% female). Floor (5.4% of patients
with the lowest possible score) and ceiling (1.2%) effects were low; 15% of patients had missing values. Internal
consistency and test-retest reliability were good (Cronbach’s alpha of 0.83 and an ICC of 0.84, respectively). Convergent
validity was demonstrated through the pattern of correlations with the EQ-5D and CU-Q2oL and known groups’ validity
was demonstrated by the instrument’s ability to discriminate between patients with different overall levels of urticaria
severity, with between-group effect-sizes (ES) ranging from 0.36 to 1.19. The UAS7 proved responsive to change with
effect sizes ranging from 0.3 to 1.52 in patients reporting improvement or deterioration in overall urticaria status. The MID
for the UAS7 score was estimated at 7–8 points, on a scale of 0–42.
Conclusions: The Spanish version of the UAS score has demonstrated a robust psychometric performance in patients
with CSU managed in conditions of usual care. It can therefore be considered a suitable instrument to assess disease
activity in clinical practice in Spanish-speaking patients. The Spanish version’s reliability and validity are similar to those
reported for other language versions of the once- and twice-daily variants of the UAS