Measuring quality of life in patients with psoriasis using the Arabic version for Morocco of the Dermatology Life Quality Index

Background Psoriasis has been demonstrated to have substantial impacts on dermatology-related functional limitations and health-related quality of life (HRQL). This study evaluated the HRQL in Moroccan psoriatics using the Arabic version of the Dermatology Life Quality Index (DLQI) and examined the psychometric properties of the questionnaire. Materials and methods The Moroccan Arabic version of the DLQI was developed and approved by the author of the questionnaire. The DLQI was administered to inpatient and outpatient adult psoriatics. Some participants completed the DLQI for a second time. Demographic and clinical characteristics were collected. Reliability of the DLQI was tested using Cronbach's coefficient alpha and intraclass correlation coefficient (ICC). Factor structure was tested by explanatory and confirmatory factor analysis. Construct validity was tested by known-groups comparison using the generalized linear model to assess factors influencing patients' HRQL. Results A total of 176 psoriatics completed the questionnaire. The mean age was 36 +/- 14years. The mean Psoriasis Area and Severity Index (PASI) score was 11.8 +/- 7.9. The mean DLQI score was 12.7 +/- 5.9 (the higher the score the greater the impairment of HRQL). Cronbach's alpha coefficient was 0.84. ICC was 0.97. The principal component analysis confirmed the bidimensional structure of the questionnaire. Factors associated with poorer HRQL were higher PASI (P<0.001), pustular and erythrodermal clinical forms (P<0.001), and older age (P=0.001). Conclusions The Arabic version for Morocco of the DLQI is reliable and valid. Severity of the psoriasis, older age, and severe clinical forms influence the HRQL of patients.