The reliability and validity study of the Turkish version of the Uncertainty about Disease and Treatment Scale in hemodialysis patients

Uncertainty is common in chronic illness and can weaken treatment adherence and psychosocial well-being. Hemodialysis involves persistent symptoms and treatment unpredictability, making uncertainty assessment clinically important. This study was methodologically designed to test the psychometric properties of the Turkish form of the Uncertainty about Disease and Treatment Scale (UC-D&TS) in hemodialysis patients. Adult patients receiving maintenance hemodialysis in a state hospital and a private dialysis center in southern Turkey were recruited between February and June 2025 ( n = 155). The scale underwent linguistic and cultural adaptation using the forward-backward translation method. Test–retest reliability was evaluated in a randomly selected subgroup of 50 participants from the original sample after a 2-week interval. Data were collected using a Descriptive Information Form and the 17-item UC-D&TS (5-point Likert). Content validity was assessed via expert review and content validity index (CVI). Construct validity was examined with Kaiser–Meyer–Olkin (KMO), Bartlett’s test, exploratory factor analysis (EFA; principal axis factoring extraction, varimax), and confirmatory factor analysis (CFA) in LISREL. Internal consistency was evaluated using Cronbach’s alpha and stability using test–retest reliability. Content validity was acceptable (CVI = 0.80). Sampling adequacy supported factor analysis (KMO = 0.821) and Bartlett’s test was significant (χ²=992.856, p < 0.001). EFA produced a four-factor solution explaining 59.13% of variance; all loadings were ≥ 0.30 and no items were removed. CFA indicated acceptable fit (χ²/df = 1.77; NNFI = 0.93; CFI = 0.94; IFI = 0.95; PNFI = 0.74; SRMR = 0.072; RMSEA = 0.071). Reliability was high (total α = 0.872; subscales α = 0.641–0.824) and test–retest reliability was excellent ( r = 0.986). The Turkish UC-D&TS, which underwent Exploratory Factor Analysis (EFA) to determine its factor structure, demonstrated satisfactory content validity, a stable four-factor structure, acceptable model fit, high internal consistency, and test-retest reliability.