Using mobile technology to support lower-salt food choices for people with cardiovascular disease: protocol for the SaltSwitch randomized controlled trial

Abstract

BackgroundCardiovascular disease (CVD) is the leading cause of early death worldwide, responsible for an estimated 29% of all global deaths. Reducing salt intake lowers blood pressure and risk of secondary cardiac events. However, identifying low salt foods can be challenging. SaltSwitch is a simple smartphone application (app) that enables shoppers to scan the barcode of packaged foods and receive an immediate, interpretive, traffic light nutrition label on the screen, along with suggestions for healthier lower-salt alternatives. A growing body of evidence suggests mobile technologies can support healthy behaviour change. However, robust evidence for the impact of smartphone interventions is lacking. This manuscript outlines the rationale and methods for a randomized controlled trial designed to determine the effectiveness of SaltSwitch in supporting people with CVD to make lower-salt food choices.Design/MethodsA 6-week, two-arm, parallel, randomized controlled trial is being undertaken in New Zealand (2 weeks baseline and 4 weeks intervention). Three hundred adults aged 40 years and older with CVD and their main household shoppers are recruited from research lists, cardiac rehabilitation clinics, and communities in Auckland. Participants are randomized to receive either the SaltSwitch smartphone app or no intervention (control). Randomisation is stratified by ethnicity and age. The primary outcome is the salt content of household food purchases. Secondary outcomes are the saturated fat and energy content of household food purchases, household food expenditure, use and acceptability of the SaltSwitch app by shoppers, and urinary sodium and blood pressure of participants with CVD. Ambulatory blood pressure and potential longer-term impact (12 weeks) of SaltSwitch will be assessed in sub-studies (n ~ 40 and n ~ 20, respectively). Household purchases of salt and other nutrients will be assessed using till receipt data electronically linked with branded food composition data.DiscussionThe results of the SaltSwitch trial will determine the effectiveness, use and acceptability of a smartphone application to support lower salt food choices and secondary prevention of CVD.Trial registrationACTRN12614000206628. Registered 30 March 2014.

Characteristics of Smartphone Applications for Nutrition Improvement in Community Settings: A Scoping Review

“…Excessive data entry for setup and logins was reportedly undesirable (36,93,98,99). Crowdsourcing data from users was useful for providing a comprehensive back-end food database (53,58) and tailoring feedback on meal healthiness (62). Within nutrition improvement trials it was found that staggered deployment of features (rolling out new features over time) helped maintain participant engagement with the application (52).…”

“…Of the 4818 titles identified from the database search, 64 articles were included: 9 reporting dietary self-monitoring trials (38)(39)(40)(41)(42)(43)(44)(45)(46), 18 reporting nutritionimprovement trials (36,(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60)(61)(62)(63), 30 reporting applicationdevelopment projects (37,, and 7 reporting qualitative studies with consumers (93)(94)(95)(96)(97)(98)(99). Five reports were published in 2016, 16 each in 2015 and 2014, 11 in 2013, and 16 between 2008 and 2012.…”

App Chronic Disease Checklist: Protocol to Evaluate Mobile Apps for Chronic Disease Self-Management

“…One such application of this technology involved a self-care app for salt intake, which has a protocol published for its use [6]. Although such apps are widely supported by health authorities and authors to enhance consumers’ engagement with self-management, more long-term randomized controlled trials (RCTs) are required to measure their clinical effectiveness and frequency of use [7,8].…”

An Acute Stroke Evaluation App

“…Also, given the importance of clinical data tracking and reporting for stroke center certification, 5 a standardized electronic clinical document generated from an integrated point-of-care tool may enhance efficiency of data abstraction. Mobile applications have proven themselves promising in many facets of medicine, from public health 6,7 to medical education 8,9 to handling the coming deluge of biometrics from ''wearable technology.'' 10 There remains, however, a dearth of studies making use of mobile applications in the neurology literature.…”