Validity and reliability of the Turkish version of the Jenkins Sleep Scale in psoriatic arthritis

Abstract

Objective The aim of this study is to investigate the validity and reliability of the Turkish version of Jenkins Sleep Scale (JSS) in psoriatic arthritis (PsA). Methods Patients with PsA according to Classification Criteria for Psoriatic Arthritis (CASPAR) were included in the study. Data about age, sex, body mass index (BMI), disease duration (month) and joint symptom duration (month) were noted. Psoriatic Arthritis Quality of Life (PsAQoL) Scale was used to assess the quality of life, Multidimensional Assessment of Fatigue (MAF) Scale was used to evaluate fatigue, and Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep quality. The reliability of JSS scale was determined by internal consistency (Cronbach's alpha coefficient). Face validity and construct validity (convergent and divergent validities) were evaluated. The correlation of the JSS with the PSQI, MAF scale, and PsAQoL scale was assessed for convergent validity. The correlation of the JSS with age, body mass index (BMI), duration of joint symptoms and disease duration were assessed for divergent validity. Results The mean age of 56 patients was 42.71 +/- 11.79. The Cronbach's alpha of the JSS was 0.862. The JSS had significant correlations with PSQI (rho = 0.653, P < 0.001), MAF (rho = 0.457, P < 0.001), PsAQoL (rho = 0.496, P < 0.001). There were no significant correlations between JSS and age (rho = -0.052, P = 0.716), BMI (rho = -0.085, P = 0.550), disease duration (rho = 0.161, P = 0.276) and duration of joint symptoms (rho = 0.107, P = 0.474). Conclusion The Turkish version of JSS is a valid and reliable instrument in PsA.