Participant Perceptions of Increasing Water Intake in Polycystic Kidney Disease

Clinical practice guidelines suggest maintaining adequate hydration in people with autosomal dominant polycystic kidney disease (ADPKD). However, the long-term perceptions of increasing water intake and the role of self-efficacy tools are unknown.

Participants randomized to the increased water intake arm in a 3-year trial were purposively sampled and invited to semistructured interviews at the end of the study. In addition, all participants (n = 78) in the increased water intake arm were invited to complete a posttrial questionnaire.

Fifteen participants completed the interview and 48 (61.5%) completed the questionnaire. Participants were motivated to adhere to the increased water intake at the start of the trial, but it became more difficult over time. Approximately half of the participants found that it was "easy" to meet fluid intake goals without interfering with their lifestyle. The main barrier was "loss of control" particularly when implementing increased water intake at social events. Furthermore, participants' somatic and emotional state undermined motivation. Regarding self-efficacy tools, the act of carrying water bottles was considered most useful for monitoring intake; self-monitoring urine specific gravity provided positive reinforcement, and mobile phone text message reminders maintained engagement. At the end of the trial, most participants had established knowledge and habits required to increase water intake but the motivation to continue long-term was contingent on a medical benefit.

Habit formation to increase water intake was perceived as relatively uncomplicated by most participants. However, the gap between intention and behavior fluctuated because of intermittent social barriers and widened over time.