ABSTRACT
Background: Chronic spontaneous urticaria (CSU) is an immunologic condition with an estimated prevalence of 0.1%. For CSU that is poorly controlled despite the use of antihistamines, omalizumab is the only treatment approved and recommended by international guidelines. Objective: Our aim was to outline the impact of treatment accessibility on CSU outcomes in the real world. Methods: Serial data on adult patients with CSU receiving care for at least 6 months at a dedicated, immunologist-led urticaria clinic at Grantham Hospital in Hong Kong between 2018 and 2023 were analyzed. Patients' clinicodemographic data, drug eligibility status (eligible for reimbursement or not), treatment step, and disease activity (weekly Urticaria Activity Score [UAS7]) were collected and compared according to drug eligibility status. Results: This study included 238 patients, 80 (33.6%) of whom were eligible for reimbursement and 158 of whom were not. No significant clinicodemographic differences, including disease activity, were found at baseline. At latest follow-up, significantly more patients in the eligible group were receiving omalizumab (28.7% vs 5.7% [P < .001]), which is equivalent to a multivariate odds ratio of 9.35 (95% CI = 3.689-23.703 [P < .001]). The discrepancy persisted even in patients with moderate-to-severe CSU whose UAS7 was 16 or higher (40.6% [13 of 32] vs 10.2% [6 of 59]; P < .001). In addition, there was significantly less dose reduction (<300 mg every 4 weeks) in the eligible omalizumab users (4.3% vs 44.4% [P = .015]). Clinically, significantly greater improvements in UAS7 were reported by the eligible group (median change -8.0 vs -5.0 [P = .021]). Conclusion: Patterns of management varied largely among patients with different drug eligibility statuses and led to disparities in health outcomes. More efforts to secure equitable access to guideline-based CSU care are warranted.
ABSTRACT
The Drug Hypersensitivity Quality of Life Questionnaire (DrHy-Q) is not currently available in Chinese. Besides, penicillin allergy (PA) is a worldwide public health challenge, and delabeling inauthentic PA can improve clinical and economic outcomes. However, its effect on health-related quality of life (HRQoL) remains poorly known. Objective: The study objective is to translate and validate a Chinese version of DrHy-Q and investigate the effect of PA delabeling on HRQoL using DrHy-Q. Methods: A Chinese DrHy-Q was translated then completed by patients with drug allergy labels for psychometric validation. Afterwards, another cohort of patients finished the Chinese DrHy-Q before and after their PA workup for pre-post comparison. Results: A total of 130 patients were studied. Sixty-three patients (79.4% female; median age = 59 ± 15 years) completed the Chinese DrHy-Q for validation (mean score = 38.9 ± 23.5). It demonstrated excellent internal consistency (Cronbach α = 0.956; 95% confidence interval [CI], 0.939-0.971) and test-retest reliability (intraclass correlation coefficient = 0.993 [95% CI, 0.969-0.998]). Construct validity was confirmed by its one-dimensional structure in factor analysis. Divergent validity was established because only 2 (out of 9) SF-36 scales showed weak negative correlations to DrHy-Q. Patients with multiple implicated drugs presented significantly higher DrHy-Q scores than those with only a single drug (42.0 ± 22.5 vs 28.7 ± 24.4; P = 0.038), showing discriminant validity. Subsequently, another 67 patients (73.1% female; median age = 56 ± 15 years) underwent PA investigations and completed their pre-post DrHy-Q. A significant drop in DrHy-Q score was shown (40.8 ± 21.7 vs 26.6 ± 22.5; Cohen's d = 0.964; P < 0.001), reflecting improvement in HRQoL. Conclusion: The Chinese DrHy-Q is reliable and valid for HRQoL assessment. PA delabeling significantly benefits patients' HRQoL. Future larger-scale studies are warranted to corroborate our findings.
