Assessment of quality of life in patients with chronic urticaria and reliability of the Dermatology Life Quality Index(DLQI)

Abstract

Objective To evaluate the influence of chronic urticaria on the quality of life in patients by the DLQI, and to assess the factor structure and reliability of the DLQI. Methods The DLQI (Chinese version) was used to evaluate the quality of life of outpatients with CU. The reliability and factor structure of the DLQI were evaluated by reliability analysis and factor analysis. Results Eighty-five patients were asked to complete the DLQI and 13 patients were excluded for other complicated disorders or unanswered items in the DLQI. The mean age was 33.43 ± 0.90 years in the 72 patients with a median clinical course of 6 months. The DLQI score, which varied from 1 to 23 with an average of 9.46 ± 0.61, was uncorrelated to the patients' age,sex, or clinical course of CU (all P ＞ 0.05). The impact of CU was observed mainly on the synptoms and feeling (50%), followed by work and study (40.67%). Factor analysis indicated that there were two dimensions with eigenvalues greater than 1.0, accounting for 53.7% of the variances. Reliability analysis showed that the Cronbach's α value was 0.836, and reached 0.849 if the item 1 in the DLQI was deleted. An analysis of variance showed that the F value was 31.88 (P ＜ 0.01 ), and Hotelling T2 test yielded an F value of 29.87 (P ＜0.01 ). Conclusions CU has a moderate impact on the quality of life in patients. DLQI can be applied to the evaluation of quality of life in patients with CU with a high reliability, but more attention should be paid to the interference from item 1 to the reliability of the assessment. Key words: Urticaria; Quality of life; Questionnaires