Achieving optimal hydration is crucial particularly for patients with nephrolithiasis. Research suggest that intake should approach 2.5 to 3.5 L per day to allow for the daily excretion of 2 to 3 litres of dilute urine1. Unfortunately, patient compliance is known to be quite poor and only around 50% of patients are compliant with this recommendation after just 6 months2.
Simple Strategies for Increased Hydration
The first step is straightforward: encourage patients to carry a reusable water bottle and aim for at least 2.5 litres daily. The water bottle acts as a cue to action and change behaviour, being a constant reminder to drink3. McCauley et al. showed that patients feel more confident about managing their hydration with a water bottle3 in comparison to dietary and pharmacological changes. Additionally, gradual habit changes, like incorporating flavoured water may be helpful. This aligns with research on treating childhood constipation, where juice was more effective than plain water. Highlighting the benefits of increased fluid intake, such as improved energy, weight management, and reduced constipation, can further motivate patients.
Hydration apps
Patients are receptive to using smart technology to improve hydration. There was a strong interest in apps or devices to support compliance with hydration in nephrolithiasis patients4. Hydration apps offer broadly similar features including:
- goal setting based of fluid intake (based on the users weight and sex),
- tracking of water intake (some apps include types of drink and various container sizes)
- reminder notifications.
Almost all of the hydration apps offer a free trial or are advert supported. At the time of writing Drink Water Reminder Pro app and BeWet app offer the best value for outright purchase with no advertising, but all of the 6 apps listed in Table 1 have good reviews in online stores and in published urological literature.
Table 1
| App name and publisher | Platform | Cost | Features |
| Drink Water Reminder Pro | iOS / Google Play | Free with ads£1.99-2.09 to remove ads | Water tracking, reminders, challenges, analytics |
| BeWet(Beforest Apps) | Google Play | Free with ads£1.99 to remove ads | Water tracking, target settings, drink types, reminders |
| My Water(My Water Drink Tracker Oy) | iOS / Google Play | Free with ads£1.29 / month£9.99 / year | Water tracking, drink types, weight tracking, reminders and analytics |
| Plant Nanny – Water Tracker (Sparkful) | iOS / Google Play | Free trial£7.99/month£69.99 /year | Water tracking, drink reminders, adjustment to exercise, virtual animated plant interface |
| Water Tracker: WaterMinder(Funn Media) | iOS / Google Play | Free with ads£3.99 monthly£8.49 / year£28.49 | Water tracking, reminders, hydration analytics, variety of units, tracking based on weight |
| Hydro Coach(Codium App Ideas) | iOS / Google Play | Free with ads£2.99 / month£19.99 / year£39.99 | Water tracking, reminders, analytics, social function with friends |
Smart water bottles
Smart water bottles like Hidrate Spark (£64-£90 depending on model) track fluid intake and sync with a smartphone for reminders. A study involving patients with kidney stones and low urine output (<1.5 litres) showed a significant increase in daily urine volume when using the Hidrate Spark compared to standard dietary recommendations5. Patients in the smart water bottle group had less difficulty remembering to drink fluids which was the main baseline factor limiting fluid intake. Although smart water bottles have been clinically proven to be useful4,5 they have potential concerns including cost, battery life, the need to be recharged as well as potential data privacy problems. Studies are also yet to determine if these increases in hydration are sustained beyond 12 weeks.
Conclusion
The most successful and simplest strategy for patients to successfully increase their hydration is simply to carry a water container6. Smart water bottles and hydration apps can be valuable tools for those who struggle to remember to drink throughout the day. However, more research is needed to understand and optimise these technologies to produce long-term changes in patient drinking habits and prevent the recurrence of conditions like kidney stones.
Published: 06/06/2024
Author: Mr Ivo Dukic, Consultant Urological Surgeon, Unversity Hospitals Birmingham NHS Foundation Trust, subspecialising in endourology and kidney stone surgery, Birmingham, United Kingdom. Further information can be found through his Top Doctors profile or book an appointment through the Harborne Hospital, HCA Healthcare or the Priory Hospital, Edgbaston, Circle Health Group. Website: ivodukic.co.uk. Twitter (X) @urolsurg
Links
Apps
https://apps.apple.com/gb/app/drink-water-reminder-pro
https://play.google.com/store/apps/details?id=com.tarahonich.bewet&hl=en
https://sparkful.app/plant-nanny
Smart water bottle
References
- Perrier ET, Armstrong LE, Bottin JH, Clark WF, Dolci A, Guelinckx I, et al. Hydration for health hypothesis: a narrative review of supporting evidence. Eur J Nutr. 2021 Apr 1;60(3):1167–80.
- Khambati A, Matulewicz RS, Perry KT, Nadler RB. Factors Associated with Compliance to Increased Fluid Intake and Urine Volume Following Dietary Counseling in First-Time Kidney Stone Patients. J Endourol. 2017 Jun;31(6):605–10.
- McCauley LR, Dyer AJ, Stern K, Hicks T, Nguyen MM. Factors Influencing Fluid Intake Behavior Among Kidney Stone Formers. The Journal of Urology. 2012 Apr 1;187(4):1282–6.
- Streeper NM, Fairbourn JD, Marks J, Thomaz E, Ram N, Conroy DE. Feasibility of Mini sipIT Behavioral Intervention to Increase Urine Volume in Patients With Kidney Stones. Urology. 2023 Sep 1;179:39–43.
- Stout TE, Lingeman JE, Krambeck AE, Humphreys MR, Zisman A, Elfering S, et al. A Randomized Trial Evaluating the Use of a Smart Water Bottle to Increase Fluid Intake in Stone Formers. Journal of Renal Nutrition. 2022 Jul 1;32(4):389–95. 1.
- Tarplin S, Monga M, Stern KL, McCauley LR, Sarkissian C, Nguyen MM. Predictors of Reporting Success With Increased Fluid Intake Among Kidney Stone Patients. Urology. 2016 Feb;88:49–56.