Background: CIU/CSU disease activity and impact on patients can be assessed with patient-reported outcomes (PROs). Disease activity is assessed with weekly Urticaria Activity Score (UAS7; 0-42). Dermatological-specific quality of life (QoL) can be assessed with Dermatology Life Quality Index (DLQI; 0-30). Separate research defined and validated CSU categorical disease health states using UAS7 scores (0=urticaria-free; 1-6=well-controlled; 7-15=mild; 16–27=moderate; 28–42=severe urticaria). Published DLQI score bands show the impact on patients’ lives for each score category: 0-1=no impact; 2–5=small; 6–10=moderate; 11–20=very large; 21–30=extremely large impact.
Objective: To assess the correlation between the changes from one UAS7 health state to another with the change between DLQI bands following treatment.
Methods: Data come from a Phase III clinical trial (GLACIAL) investigating the effects of omalizumab on refractory CSU patients. Treatment was administered at baseline and once every 4 weeks until Week 20; patients were followed-up until Week 40. PRO data were collected at baseline and Weeks 12, 24, and 40. Data were analyzed using latent growth models (LGMs) which calculate individual patient intercepts and slopes of change in each PRO and correlate these, allowing assessment of how closely changes from one UAS7 health state to another are reflected in a change from one DLQI band to another. Categorical UAS7 health states were ranked from 0 (urticaria-free) to 4 (severe urticaria); DLQI bands ranked from 0 (DLQI=0-1) to 4 (DLQI=21-30).
Results: At baseline mean UAS7 score was 30 reflecting inclusion criteria of patients in moderate and severe health states (mean health state rank =3.68). The mean baseline DLQI score was 12 corresponding to a very large effect on patient’s lives (mean DLQI band =2.62). At Weeks 12, 24 and 40 the mean UAS7 health states ranks were 1.86, 1.42 and 2.38; mean DLQI bands were 1.20, 0.90 and 1.71, respectively. LGMs found that changes over 40 weeks in UAS7 health states and DLQI bands were highly correlated: 0.93.
Conclusions: Results show that the response to treatment is reflected in a reduction of symptoms and progression to a lower UAS7 health state. This highly correlates with a reduction of disease impact on patients’ lives and is reflected in a lower DLQI band. Using simpler, categorical scores can facilitate clinical assessments of severity and change in CSU health states and disease impact.
