Software Application for Low-Sodium Diet Trial (SALT)

This a single-center prospective randomized controlled trial. Subjects will be assigned to the standard of care dietary recommendations for a low sodium diet (LSD) vs. the standard of care dietary recommendations for a low sodium diet plus a mobile application that analyzes sodium content of shopping lists that are created prior to shopping trips to the grocery store over an 8-week study period. An initial pilot phase will be done to ensure adequate percentage of subjects are completing the study in the intervention group and that adequate data is being collected.

The study will be designed as a single-center prospective randomized controlled trial. Subjects will be assigned to the standard of care dietary recommendations handout vs a mobile application that analyzes sodium content of shopping lists that are created prior to shopping trips to the grocery store. The intervention will be administered for 8 weeks. The trial will be split into two phases, 1) Pilot phase, and 2) Trial phase. Once we have enrolled 20 subjects in the intervention arm, we will analyze whether an appropriate percentage of subjects have completed the study and adequate data is being collected. At the end of the trial, outcomes will be measured as follows:

1. Mean change in score on a Knowledge of Low Sodium Diet validated questionnaire completed at baseline and at the end of the study (primary outcome)

   -- The minimum and maximum scores are 0 and 26, respectively. A higher score indicates a better knowledge of LSD and we hypothesize that use of the software application will result in a higher score on the questionnaire.
2. Mean change in urinary sodium measured on two baseline 24hr collections and two end of study 24hr collections (primary outcome)

   -- We hypothesize that an always-available application that helps guide subjects in grocery choices will decrease the 24hr sodium level compared to the control group
3. Within-group assessment of how often the Healthcart application is used to create shopping carts and recording of changes in shopping cart sodium score over the study period (secondary outcome)

   -- Healthcare interventions delivered via mobile applications are quite novel at this time and the data regarding uptake and usage is limited. These outcome measures will add to this body of data.
4. Clinical data (exploratory outcomes)

Eligibility Criteria:
Inclusion Criteria:

* Male and female adults aged 18 or greater and any race/ethnicity
* Diagnosis of Kidney Stone Disease (KSD) within previous 6 months via:

  * Surgical procedure for KSD -- OR
  * Imaging demonstrating KSD (abdominal xray or CT scan)
* Diagnosis of hypernatriuria (elevated urinary sodium \>150mmol/d) on 24-hour urine collection within previous 6 months
* Mobile phone with iOS
* Working email address
* Food purchased at Wegmans grocery stores in the Rochester area during the study period
* Willingness to participate and able to provide informed consent

Exclusion Criteria:

* Pregnancy
* Current use of medications prescribed for prevention of KSD
* Current prescription of low sodium diet due to another medical condition
* Inability or unwillingness to use mobile application
* Do not participate in grocery shopping