Translating the science of quality of life into practice: What do dermatology life quality index scores mean?

Abstract

This study's aim was to determine the relationship between Dermatology Life Quality Index (DLQI) scores and a Global Question (GQ) concerning patients' views of the overall impairment of their skin-related quality of life (QoL), and to express this relationship by identifying bands of DLQI scores equivalent to each GQ descriptor. A DLQI questionnaire and the GQ were mailed to 3834 adult general dermatology outpatients. There were 1993 (52%) responses: male 841; female 1152. Mean DLQI score = 4.86 (range 0-30, standard deviation (SD)=5.83). Mean GQ score = 1.22 (range 0-4, SD = 1.20). The mean, mode, and median of the GQ scores for each DLQI score were used to devise several sets of bands of DLQI scores, and κ coefficients of agreement calculated. The set proposed for adoption is: DLQI scores 0-1 = no effect on patient's life (GQ = 0, n = 754); DLQI scores 2-5 = small effect on patient's life (GQ = 1, n = 611); DLQI scores 6-10 = moderate effect on patient's life (GQ = 2, n = 327); DLQI scores 11-20 = very large effect on patient's life (GQ = 3, n = 242); DLQI scores 21-30 = extremely large effect on patient's life (GQ = 4, n = 59); κ coefficient 0.489. Banding of the DLQI will aid the clinical interpretation of an individual's DLQI score and allow DLQI scores to inform clinical decisions. Copyright © 2005 by The Society for Investigative Dermatology, Inc.