Feasibility of trial methodology, intervention delivery, and initial outcome signals of an app-based ecological momentary intervention to promote mental well-being: a feasibility Trial within Cohort study in individuals with Long COVID
Mental health promotion in individuals with Long COVID enrolled in a digital cohort
Current interventions as of 03/07/2026: In a two-arm, parallel-group, randomised controlled Trial within Cohort study (TwiC), registered individuals from a digital cohort (DigiHero Study; https://webszh.uk-halle.de/digihero/en/digi-hero-study/) with Long COVID identified as eligible in this cohort will be randomly assigned to either the experimental condition, which receives the EMI in addition to Care-As-Usual (CAU), or to the control condition, which comprises CAU only. Participants identified as eligible in the DigiHero cohort will be randomly assigned (1:1) to the experimental or control condition at the participant level. Block randomization in blocks of 6 will be performed by an independent researcher using a computer-generated sequence. The training is delivered through a smartphone-based EMI over 40 days. The EMI aims to facilitate the real-time and real-world transfer of intervention content, principles, and techniques into participants' daily lives. The training is grounded in the principles of Cognitive Behavioral Therapy (CBT) and Acceptance and Commitment Therapy (ACT). Key components include breathing exercises, positive imagery, diary entries of joyful moments and gratitude, and self-monitoring through EMA data as well as physiological data tracked by wearables or smartwatches. In addition, the intervention provides personalized feedback and EMI components tailored to person, moment and context based on participants’ EMA responses. The EMI consists of three different EMI delivery schemes and monitoring: - Enhancing delivery scheme: In the course of the training phase, participants are successively introduced to new EMI components based on CBT and ACT during the first 14 days. - Consolidating delivery scheme: EMI components that are already known to the participant (i.e., have been practised as enhancing EMI components) will be offered as consolidating EMI components, encouraging practice. - Adaptive delivery scheme: Participants’ responses to sho
Current key inclusion criteria as of 03/07/2026: 1. At least 18 years or older 2. Access to a smartphone running on iOS or Android, which will be continuously available for the duration of the study. 3. Registered in the DigiHero Cohort 4. Presence of Long COVID _____ Previous key inclusion criteria: 1. At least 18 years or older 2. Access to a smartphone running on iOS or Android, which will be continuously available for the duration of the study. 3. Registered in the DigiHero Cohort 4. Presence of post-acute infection syndrome (PAIS)
1. Not able to give informed consent 2. Insufficient language abilities in the available languages: German