Adaptation and validation of the Bengali version of the Chronic Urticaria Quality of Life Questionnaire (CU-Q2oL)

Abstract

Background: Chronic urticaria exerts a profound impact on quality of life. Recent guidelines recommend its evaluation in all chronic urticaria patients. Currently, the Chronic Urticaria Quality of Life Questionnaire (CU-Q2oL) is the only validated tool to assess chronic urticaria-specific quality of life. Objective: To validate and adapt the CU-Q2oL to the Bengali language for its widespread use. Methods: The CU-Q2oL questionnaire was translated into Bengali. Its internal consistency and reliability were tested by asking 42 chronic urticaria patients to complete this version. They completed the validated Bengali Dermatology Life Quality Index and Urticaria Control test questionnaires, and their scores were correlated with CU-Q2oL score to assess the validity of our Bengali version. Results: The mean CU-Q2oL score of our patients (mean age 38.41 ± 13.4 years, male: female 29:13) was 48.8 ± 16.5. Domain 4 (sleep problems) was worst affected, followed by domain 1 (pruritus), while domain 2 (swelling) was least affected. We detected an excellent overall internal consistency (Cronbach’s alpha = 0.93) of our version and nearly complete agreement (intra-class correlation coefficient = 0.91) between the test-retest scores. We found a significant positive correlation between the overall CU-Q2oL and Dermatology Life Quality Index scores (rs = 0.53, P = 0.0002), thus implying the validity of our version. Additionally, we noted a significant negative correlation between the overall CU-Q2oL and Urticaria Control test scores (rs = -0.48, P = 0.0007), suggestive of a more severe impairment of quality of life with poorer disease control. Limitations: Small sample size, observational design and bias in test-retest reliability analysis due to the use of rescue therapy in-between assessment sessions were important limitations of our study. Conclusion: The Bengali version of CU-Q2oL questionnaire is a valid and reliable tool suitable for both clinical and research use in Bengali speaking chronic urticaria patients.