Uraemic Pruritus in Dialysis Patient (UP-Dial) questionnaire: creation and validation of the Polish language version

Introduction
Uraemic pruritus is a common and burdensome symptom in patients undergoing haemodialysis. Though a significant negative impact of chronic itch on patient’s quality of life is proved, this problem is still often underestimated in clinical practice. Various instruments describing itch are in use, however only recently a specific instrument for uraemic itch – Uraemic Pruritus in Dialysis Patient (UP-Dial) – questionnaire has been created.
Aim: To translate and to validate the Polish version of the UP-Dial questionnaire.

Material and methods
Forward and backward translations were conducted according to international standards. The validation was performed on a group of 30 patients undergoing haemodialysis and suffering from uraemic itch. Respondents completed the questionnaire twice with a 3–7 days’ interval. Moreover, for convergent validity, the subjects were asked to assess their itch with the Numerical Rating Scale (NRS), 4-Item Itch Questionnaire (4IIQ) as well as ItchyQoL questionnaire.

Results
The Polish version of the UP-Dial questionnaire showed very good internal consistency – Cronbach a coefficient was 0.90 for total score. The reproducibility assessed with the intraclass correlation coefficient (ICC) was also very good – 0.9. Furthermore, UP-Dial correlated strongly with NRS (r = 0.74, p < 0.01), 4IIQ (r = 0.82, p < 0.01) and ItchyQoL (r = 0.88, p < 0.01).

Conclusions
The Polish version of the UP-Dial questionnaire showed high internal reliability, validity and reproducibility and can be widely used both in research and in daily clinical practice.