Anxiety, obesity, diabetes — there’s apps for all that and more. But which risk factors and outcomes actually respond to smartphone-based interventions? A new paper in The Lancet Digital Health separates helpful software from homescreen clutter.
Mountains of data went into this study. The umbrella review and meta-analysis covered 78 systematic reviews, 496 primary studies, and over 177k participants.
Apps came out looking pretty good. They made a dent in 21 of 31 outcomes.
- Users got moving, adding to their step counts and exercise time.
- BMI, weight, and waist size (but somehow not body fat percentage) fell.
- On the mental health front, anxiety, mindfulness, and stress saw the most positive movement, with depression and wellbeing just behind.
- Glucose levels improved — more than any other metric, at that.
But the study was a heartbreaker for cardiovascular disease apps (and a grab bag of other categories).
- Blood pressure was the only CV outcome that responded to apps.
- Cholesterol, triglycerides, and CV disease mortality didn’t budge.
- Fruit and veggie intake, smoking, and hospitalization were also unchanged.
Here’s where the lessons on better building and deploying apps come in. Researchers, clinicians, developers, and policymakers, take note.
- Tracking and monitoring were most useful when it came to physical activity, glucose management, nutrition, and medication adherence.
- Educational content went a long way for mental health.
- Support from healthcare professionals or a community was broadly helpful.
- Goal-setting and behavioral planning were generally underused.
Some outcomes might just be harder to achieve, though.
- The researchers theorize that apps are good at short-term behavioral changes, but struggle with conditions that require intensive, multifaceted care.
The Takeaway
App-based interventions are cheap, non-invasive, and low commitment, but this study shows they’re not useful for all conditions. Take that how you will, either as a sign to ditch smartphones for some types of care or double-down with better features.

