Minimal clinical important difference (MCID) of the Thai Chronic Urticaria Quality of Life Questionnaire (CU-Q(2)oL)

作者：Kulthanan Kanokvalai; Chularojanamontri Leena^*; Tuchinda Papapit; Rujitharanawong Chuda; Baiardini Ilaria; Braido Fulvio

来源：Asian Pacific Journal of Allergy and Immunology, 2016, 34(2): 137-145.

DOI：10.12932/AP0674.34.2.2016

• chronic urticaria
• Chronic Urticaria Questionnaire (CU-Q2oL)
• minimal clinical important difference (MCID)
• reliability
• validation

Background: Chronic urticaria (CU) has negative impacts on patients' daily lives. The Chronic Urticaria Quality of Life Questionnaire (CU-Q(2)oL) evaluates quality of life impairment attitudes among chronic urticaria patients. Although the CU-Q(2)oL has been validated in several languages, the minimal clinical important difference (MCID) of the CU-Q(2)oL has never been determined.
Objective: This study aimed to investigate the validity, reliability, responsiveness to change, and MCID of the Thai CU-Q(2)oL.
Methods: The Thai CU-Q(2)oL was translated with permission from the authors of the original Italian version. The Thai CU-Q(2)oL, the validated Thai Dermatology Life Quality Index (DLQI), and the Urticaria Activity Score were assessed for 166 patients to evaluate validity and internal consistency. The three questionnaires were then administered to 124 patients to determine the test-retest reliability, responsiveness, and MCID of the Thai CU-Q(2)oL.
Results: The Thai CU-Q(2)oL contained only three domains, whereas the Italian version revealed six domains. Nevertheless, the total variance of the Thai CU-Q(2)oL (60.5%) was very close to that of the Italian version (60.0%). The validity of the Thai CU-Q(2)oL was shown by strong correlations between CU-Q(2)oL and DLQI scores. The Thai CU-Q(2)oL also had high internal consistency and test-retest reliability. Distribution-based, receiver operating characteristic analysis, and anchor based approaches yielded MCID values of 3.98.0, 15, and 21.1, respectively.
Conclusions: The Thai CU-Q(2)oL is a valid and reliable instrument. We propose that a difference in the Thai CU-Q(2)oL score of 15 (MCID) is the smallest change patients perceive as a meaningful improvement.

• 出版日期2016-6