The Efficacy of Zemedy, a Mobile Digital Therapeutic for the Self-Management of Irritable Bowel Syndrome: a Cross-Over, Randomized Controlled Trial

JMIR Mhealth Uhealth. 2021 Apr 14. doi: 10.2196/26152. Online ahead of print.

Melissa Hunt 1, Sofia Miguez 1, Benji Dukas 1, Obinna Onwude 2, Sarah White 3


Author information

  • 1Department of Psychology, University of Pennsylvania, 425 S University AveLevin Building, Philadelphia, US.
  • 2Bold Health Limited, UK, London, GB.
  • 3Population Health Research Institute, St George's University of London, London, GB.


Background: Patients with irritable bowel syndrome (IBS) experience abdominal pain, altered bowel habits, and defecation-related anxiety which can result in reduced productivity and impaired health related quality of life (HRQL). Cognitive-behavioral therapy (CBT) has been shown to reduce symptoms of IBS and to improve HRQL, but access to qualified therapists is limited. Smartphone-based digital therapeutic interventions have the potential to increase access to guided CBT at scale but require careful study to assess their benefits and risks.

Objective: To test the efficacy of a novel app, Zemedy - a mobile digital therapeutic that delivers a comprehensive CBT program to individuals with IBS.

Methods: This was a cross-over randomized controlled trial (registration number NCT04170686). Participants were recruited online. Patients were randomly allocated to either immediate treatment (N = 62) or waitlist control (N = 59). The Zemedy app consists of 8 modules focusing on psychoeducation, relaxation training, exercise, the cognitive model of stress management, applying CBT to IBS symptoms, reducing avoidance through exposure therapy and behavioral experiments, and information about diet. Users interact with a chatbot that presents the information and encourages specific plans, homework and exercises. The treatment was fully automated, with no therapist involvement or communication. At baseline and after 8 weeks, participants were asked to complete the battery of primary (Irritable Bowel Syndrome Quality of Life (IBS-QoL), Gastrointestinal Symptom Rating Scale (GSRS)) and secondary outcome measures (the Fear of Food Questionnaire (FFQ), the Visceral Sensitivity Index (VSI), the GI Cognition Questionnaire (GI-COG), the Depression, Anxiety, Stress Scale (DASS) and the Patient Health Questionnaire (PHQ-9)). Waitlist controls were then offered the opportunity to cross over. All participants were assessed one more time at 3 months post-treatment completion.

Results: Both intent-to-treat and completer analyses at post-treatment revealed significant improvement for the immediate treatment group compared to the waitlist control group on both primary and secondary outcome measures. Gains were generally maintained at 3 months post-treatment. Scores on the GSRS, IBS-QoL, GI-COG, VSI and FFQ all improved significantly more in the treatment group [F(1,79) = 20.49, P < .001, Cohen's d = 1.01; F(1,79) = 20.12, P < .001, d = 1.25; F(1,79) = 34.71, P < .001, d = 1.47 and F(1,79) = 18.7, P < .001, d = 1.07; F(1,79) = 12.13, P = .001, d = .62]. Depression improved significantly as measured by both the PHQ9 [F(1,79) = 10.5, P = .002, d = 1.07] and the DASS Depression Subscale [F(1,79) = 6.03, P = .016, d = .83], as did the stress subscale of the DASS [F(1,79) = 4.47, P = .04, d = .65] in the completer analysis but not the intent-to-treat analysis. The impact of treatment on HRQL was mediated by reductions in catastrophizing and visceral sensitivity.

Conclusions: Despite its relatively benign physical profile, IBS can be an extraordinarily debilitating condition. Zemedy is an effective modality to deliver CBT for individuals with IBS, and could increase accessibility of this evidence-based treatment.

Clinicaltrial: This trial was registered at ClinicalTrials.gov as NCT04170686.

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