mHealth
MoodGYM improves population wellbeing
Open access · cc by · source: Europe PMC
In a large UK web RCT, automated MoodGYM raised mental well-being versus wait-list control despite high intervention attrition.
Study at a glance
- Design
- RCT — Fully automated MoodGYM vs waiting-list; ITT mixed models
- N
- N=3070 · Randomized NHS Choices users; high differential attrition
- Population
- NHS Choices website users randomized to MoodGYM or wait-list
- Outcome
- WEMWBS well-being at 6 and 12 weeks
Structured fields used in claim comparison tables when every cited study has a complete layer.
Key findings
3070 people were randomized. The intervention × time interaction was highly significant: adjusted WEMWBS differences favored MoodGYM by about 2.5 points at 6 weeks and 2.9 at 12 weeks (≈Cohen d 0.34). Attrition was much higher in the intervention arm (73.5%) than control (26.9%).
Methodology
Users of the NHS Choices site were randomized to fully automated MoodGYM or a waiting-list control. Well-being (WEMWBS) and related outcomes were assessed at baseline, 6 weeks, and 12 weeks in an intention-to-treat mixed-model analysis.
Limitations
High differential dropout can bias estimates even with ITT modeling. The trial targets general well-being, not diagnosed anxiety disorders, and wait-list controls may inflate apparent benefit.
How this study connects
Role on claims
Each row is a claim on a concept or method page where this paper supports, challenges, or qualifies the statement. Roles are hand-checked — not a model guess.
Multiple studies in this library examine mhealth with empirical patient or population outcomes rather than opinion alone.
Evidence for the claim as stated.
3070 people were randomized. The intervention × time interaction was highly significant: adjusted WEMWBS differences favored MoodGYM by about 2.5 points at 6 weeks and 2.9 at 12 weeks (≈Cohen d 0.34). Attrition was much higher in the intervention arm (73.5%) than control (26.9%).
Evidence for the claim as stated.
Effect sizes and settings differ across mhealth studies — digital vs clinic, trial vs observational — so results should not be pooled casually.
Evidence for the claim as stated.
Intention-to-treat mixed models can still leave a trial hard to interpret when dropout is large and unequal. NHS Choices users randomised to MoodGYM versus wait-list showed adjusted WEMWBS advantages of about 2.5 points at 6 weeks and 2.9 at 12 weeks, but attrition was 73.5% in the intervention arm versus 26.9% in control.
Evidence for the claim as stated.
NHS Choices users randomised to MoodGYM versus wait-list (n=3,070) were analysed with an ITT mixed model: adjusted WEMWBS differences favoured the programme by about 2.5 points at 6 weeks and 2.9 at 12 weeks (≈Cohen d 0.34). Attrition was 73.5% in the intervention arm versus 26.9% in control. High differential dropout can bias even an ITT model if missingness is related to outcome.
Evidence for the claim as stated.
ITT mixed models do not travel with equal credibility across dropout patterns. MoodGYM's 2.5–2.9 point WEMWBS advantage sits on 73.5% versus 26.9% attrition and a wait-list control. Kokoro-app's 2.5-point PHQ-9 contrast had high engagement among those assigned CBT. Same analysis label, very different missing-data threats.
Evidence for the claim as stated.
MoodGYM's primary analysis was an ITT mixed model of WEMWBS at baseline, 6 and 12 weeks in 3,070 randomised NHS Choices users. The intervention×time interaction was highly significant: adjusted differences favoured the programme by about 2.5 points at 6 weeks and 2.9 at 12 weeks (≈Cohen d 0.34). Attrition was 73.5% in the intervention arm versus 26.9% in wait-list control — a missing-data threat the mixed model does not erase.
Evidence for the claim as stated.
A mixed model with a randomised control (MoodGYM, Kokoro-app, Facebook walking, Glucose Buddy) answers a different question from a mixed model of change inside one arm (IntelliCare field trial, Fitbit wear). Significant PHQ-9/GAD-7 improvement to 37%/42% below 5, or MVPA doubling from 93.8 to 195.3 min/week, can be expectancy, concurrent care, or the surrounding activity trial. Those papers do not licence the same causal sentence as a 2.5-point randomised PHQ-9 gap.
Evidence for the claim as stated.
Durability and missingness pull in opposite directions across trials that share the modelling family. Facebook walking's 155 min/week advantage vanished after the stimulus ended despite 87.3% retention; MoodGYM's WEMWBS advantage persisted to 12 weeks on paper while 73.5% of the intervention arm had left. A student who treats 'mixed-model p < .05' as one finding will miss both limits.
Evidence for the claim as stated.
Open questions
Tensions this paper is part of
From concept pages' “where studies disagree.” Disagreement means the same question; scope means different assays, populations, or outcomes.
Effect sizes and settings differ across mhealth studies — digital vs clinic, trial vs observational — so results should not be pooled casually.
- Supports · Woebot chatbot for substance use
- Supports · Audio vs text produce-app RCT
ITT mixed models do not travel with equal credibility across dropout patterns. MoodGYM's 2.5–2.9 point WEMWBS advantage sits on 73.5% versus 26.9% attrition and a wait-list control. Kokoro-app's 2.5-point PHQ-9 contrast had high engagement among those assigned CBT. Same analysis label, very different missing-data threats.
A mixed model with a randomised control (MoodGYM, Kokoro-app, Facebook walking, Glucose Buddy) answers a different question from a mixed model of change inside one arm (IntelliCare field trial, Fitbit wear). Significant PHQ-9/GAD-7 improvement to 37%/42% below 5, or MVPA doubling from 93.8 to 195.3 min/week, can be expectancy, concurrent care, or the surrounding activity trial. Those papers do not licence the same causal sentence as a 2.5-point randomised PHQ-9 gap.
- Supports · Can a CBT phone app help stubborn depression?
- Supports · IntelliCare app suite field trial
- Supports · Fitbit wear during an activity trial
Durability and missingness pull in opposite directions across trials that share the modelling family. Facebook walking's 155 min/week advantage vanished after the stimulus ended despite 87.3% retention; MoodGYM's WEMWBS advantage persisted to 12 weeks on paper while 73.5% of the intervention arm had left. A student who treats 'mixed-model p < .05' as one finding will miss both limits.
- Supports · Facebook team walking RCT
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