Quality of life instrument for Turkish people with skin diseases

Abstract

To develop a new, short, self-administrated subjective quality of life (QOL) instrument for Turkish people with skin diseases. The 11-item questionnaire of QOL instrument was developed from 200 consecutive dermatological patients' replies. The reliability and validity of the instrument was tested on data gathered from 278 patients with skin diseases attending a dermatology outpatient department and 49 normal subjects. Construct validity was assessed by an exploratory factor analyses and comparisons between patients rated severe and not severe, as well as between normal and patient groups. Reliability was assessed from the internal consistency of the scales and the correlations were made between scores from a 7-10-day retest by using intraclass correlation coefficient. Factor analyses found six separate dimensions of QOL involving skin disease: social life, emotional life, daily activity, symptoms, cognitive life and sexual life. In addition, 81.3% of common variance was explained by the above factors, all of which correlated with the scale scores of the instrument. The instrument scales were internally consistent (Cronbach's alpha= 0.77-0.84) and scale scores were reproducible after 7-10 days (ICC = 0.63-0.88). Significantly, correlations between scale scores and physician's assessment of the severity of the skin disease were found. Significant differences between diagnostic groups were observed with higher scores for patients with psoriasis, urticaria and acne than those with eczema in the emotional life domain (P < 0.05). In the sexual life domain, however, the eczema group had higher scores than patients with psoriasis, urticaria or acne (P < 0.01). The instrument provides valid and reliable assessments of QOL in Turkish patients with skin disease.