Abstract
BACKGROUND: Patients with advanced kidney disease suffer from burdensome symptoms, which should be assessed by valid and reliable patient-reported outcome measures. This study aimed to provide a translation, cultural adaptation, and validation of the Czech version of the IPOS-r. METHODS: The IPOS-r was translated to Czech and culturally adapted using cognitive interviews. During the validation phase, patients and staff in dialysis centres and outpatient renal clinics completed the IPOS-r. Internal consistency was tested with Cronbach's alpha, its reliability via intraclass correlation coefficient for total IPOS-r score, and weighted Kappa (for test-retest and interrater reliability of individual items). Convergent validity was tested with Spearman correlation to Kidney Disease Quality of Life Survey-Short Form 1.2 (KDQOL-SF 1.2). We assessed sensitivity to change using a distribution-based approach. RESULTS: Two sets of translators independently performed forward and backward translations of the IPOS-r. Ten patients and ten health care professionals participated in cognitive pre-testing. The sample size for validation included 88 patients (mean age 66 ± SD13.8; 58% men) who were treated with haemodialysis (70.5%), home haemodialysis (5.5%), peritoneal dialysis (3%), and conservative management (21%). Cronbach's alpha was 0.72, and the intraclass correlation was 0.84 for test-retest reliability and 0.73 for interrater reliability. The IPOS-r correlated with KDQOL-SF 1.2 had a rho between 0.4-0.8 for most of the IPOS-r items, showing good convergent validity. The IPOS-r measure is feasible and takes 9 minutes to complete. Patients who reported a change in health status after 1 month demonstrated a total IPOS-r score change of eight points in both positive and negative directions. CONCLUSIONS: The process of translation and cultural adaptation of the IPOS-r was successful, and the Czech IPOS-r measure is a valid and reliable tool. The Czech IPOS-r can be used to assess symptoms in patients with advanced chronic kidney disease. TRIAL REGISTRATION: GAUK [82121].