Diet and multiple sclerosis: Behaviour change techniques in the digital health application levidex

Multiple sclerosis (MS) is a chronic disease affecting the central nervous system. People with MS (PwMS) have a strong need for lifestyle-related information, and their motivation to change dietary behaviour is typically high. A recent randomised controlled trial showed that the digital health application (DiGA) levidex led to an increase in diet quality in an early MS cohort.

This study aimed to provide an analysis of the diet-related behaviour change techniques (BCTs) applied in 'levidex'.

The BCT Taxonomy v1 (BCTTv1) was used to report BCTs of diet-related content in levidex. BCTs were independently coded by two raters using MAXQDA 2022. Disagreements were resolved by a third rater. Inter-rater reliability was assessed as percentage agreement and coefficient kappa. Identified BCTs were then linked to theoretical mechanisms of action (MoAs) using the interactive Theory and Techniques Tool.

Rater agreement was 79.01% (coefficient kappa 0.78). Overall, 28 BCTs were identified, with 202 BCT codings across all levidex content targeting dietary behaviour. The most frequently used BCTs were 'instruction on how to perform the behaviour', 'information about health consequences' and 'credible source'. Identified BCTs could be linked to 24 MoAs.

A broad range of BCTs focussing on skill development and information provision from credible sources are utilised in levidex to facilitate the adoption of health-promoting dietary habits. BCT taxonomy coding is a feasible approach to analyse BCTs applied in DiGAs.

Linking outcomes from effectiveness studies to specific active ingredients facilitates a clearer understanding of underlying intervention effects and may ultimately allow evidence syntheses to identify a core set of BCTs for nutrition-focused interventions.