Smartphone App for Remote Dietary Counseling in Kidney Disease

In patients with chronic kidney disease (CKD), there is risk of mortality associated with healthy dietary patterns. Nevertheless, not all patients receive counseling from a dietitian, due, in part, to dietitian availability, travel distance, and cost. Alex R. Chang, MD, MS, and colleagues recently conducted a study to examine the feasibility of telecounseling supported by a smartphone application to reduce sodium intake and improve overall dietary quality in patients with early CKD. Results of the pre-post, mixed methods feasibility study were reported in the Journal of Renal Nutrition [doi https://doi.org/10.1053/j.jrn.2019.03.080].

The single-center study was conducted at Geisinger Medical Center (Danville, PA) from April to November 2016, and included 16 patients with stage 1-3 CKD in central/northeast Pennsylvania. The researchers tested two different smartphone applications. For the first seven patients, the researchers utilized data from other researchers involved in behavioral modification research using applications to collaborate with Vibrent Health to customize their health platform. The customization included a daily sodium tracker, a daily survey regarding servings of fruit and vegetables, daily messages about healthy lifestyle tips, weekly target goals for sodium and fruit/vegetable intake, and a patient-provider portal to enable sharing of dietary data and messaging. Patient feedback on this initial application reported negative opinions of the application’s functionality. The latter nine patients used MyFitnessPal, a commercially available, free software program.

Patients were asked to enter their dietary intake daily using the assigned smartphone application. The first week focused on collection of dietary data, 24-hour urine collections, and 24-hour dietary recalls. In weeks 2 to 8, patients received weekly telephone calls from a registered dietitian nutritionist (RDN).

Average age of the 16 patients in the study was 64.7 years, 31% were female, 100% were non-Hispanic white, 32% had a college degree, and 50% had annual income ≥$75,000. Comorbidities included hypertension (81%), diabetes (69%), hyperlipidemia (63%), atherosclerotic cardiovascular disease (31%)l and depression/anxiety (13%).

In general, adherence with food tracking in both groups was excellent. Among the seven patients using Vibrent, all participants logged in at least 75% of total days; five of the seven entered complete dietary data >98% of the days. Among the nine patients using MyFitnessPal, seven entered complete dietary data at least 75% of the total days (the other two entered complete dietary data 50% and 32% of the time). During the course of the intervention, entry of dietary data remained consistent. Adherence with the weekly RDN telephone calls was also excellent overall: ten of the 16 patients in the total cohort completed seven calls, four completed six calls, one completed four calls, and one completed no calls.

Twelve participants had 24-hour recall data. In those patients, sodium intake decreased by 604 mg/day (95% confidence interval [CI], –1104 to –104; P=.02). Fifteen patients had 24-hour urine data. Among those, the change in 24-hour urine sodium was not significant (21 mg/day; 95% CI, –623 to 665; P=.95).

The mean Healthy Eating Index 2015 (HEI-2015) score improved by 3.97 points (95% CI, 0.03-7.91; P=.05). The fruit and vegetable intake categories of the HEI-2015 improved; the dairy score component tended to worsen. There were no changes in intake of red meat or processed meat. Results were similar for Vibrent users and MyFitnessPal users in change in sodium intake, sodium excretion, and total HEI-2015 score.

There was a 3.4 pound decrease in mean weight (95% CI, –6.6 to –0.1; P=.04). There was a trend toward improvement in daytime systolic blood pressure, daytime diastolic blood pressure, nighttime systolic blood pressure, and nighttime diastolic blood pressure. There was no change in 24-hour urine albumin excretion and no patient  had changes in blood pressure medication use over the 8-week study period.

Responses to a patient satisfaction survey indicated high satisfaction with the study. There was universal agreement that study participation enabled participants to learn to eat healthier. When asked about the reactions to the smartphone app, responses were mixed: patients in the Vibrent group reported lower satisfaction while those in the MyFitnessPal group reported high satisfaction.

The authors cited some limitations to the pilot study, including collecting baseline 24-hour urine sodium and 24-hour dietary recall data during the first week of the study while patients were using the application to enter dietary data. This may have affected patient behavior, resulting in lower baseline sodium intake or excretion. In addition, the use of modest lottery prizes (two $100 gift certificates) may have increased adherence to entry of dietary data. Finally, study participants were mostly white, fairly well-educated men in a rural area, possibly limiting the generalizability of the findings to minorities and individuals with low literacy.

In summary, the researchers said, “We found that use of smartphone applications in conjunction with remote RDN telephone counseling was feasible and well-accepted although additional research in more diverse populations is needed. Participation in the program was associated with improved sodium intake assessed by multiple dietary recall and improvements in HEI-2015 score, ambulatory blood pressure, and weight. Future randomized trials in urban and rural settings are needed to test the efficacy of dietary application-supported telecounseling.”

Takeaway Points

  1. Researchers conducted a pre-post, mixed methods feasibility study to assess the feasibility of dietary telecounseling supported with a smartphone application to reduce sodium intake and improve dietary quality in patients with early chronic kidney disease.
  2. Adherence to the intervention was excellent; 88% of participants entered dietary data at least 75% of total study days.
  3. Following the intervention, there were improvements in sodium intake, Healthy Eating Index 2015 score, weight, and ambulatory blood pressure.