Development and Validation of the Thirst Distress Scale for Patients with Autosomal Dominant Polycystic Kidney Disease

Abstract Background and Aims: Thirst, is the main driver for fluid consumption. Abundant water intake is advised for patients with autosomal dominant polycystic kidney disease (ADPKD). However, daily routines may limit water intake. There is no established tool to quantify the drivers of water intake in ADPKD patients. The aim of this study was to modify and validate a thirst distress scale (TDS) to identify the factors that influence water intake in ADPKD patients. Methods The TDS-heart failure questionnaire was first modified to TDS-PKD to adapt to patients with ADPKD to assess (a) the intensity of thirst, (b) the consequences if the quench for thirst is not satisfied enough and (c) the disturbing effects of thirst on quality of life. Then, the TDS-PKD questionnaire was translated to Turkish using the guidelines of the World Health Organization. An electronic survey with the SurveyMonkey platform was used to collect data. Thirst intensity was evaluated using a visual analog scale (VAS). Results The questionnaire was filled in by 186 ADPKD patients, of which 126 were on tolvaptan therapy. The TDS-PKD questionnaire showed good internal consistency, with a Cronbach's alpha value of 0.859. According to the exploratory factor analysis, a three-factor structure was obtained. Three factors explained 60.7% of the total variance. There was a positive and statistically significant correlation between the total TDS and VAS scores (r = 0.589, p < 0.001). The average TDS-PDK score was 39.0 ± 1.4. Conclusion The TDS-PKD questionnaire is a valid and reliable tool for evaluating the thirst distress in ADPKD patients.