Apart from cardiometabolic parameters, health tracking apps were found to be effective for glucose management, such as regulating HbA1c and fasting blood glucose concentrations and for improving anxiety, stress and other areas related to mental health
The study, conducted by researchers from the Nestlé Institute of Health Sciences, the University of South Australia, Central Queensland University, and tertiary institutions in the UK, US and Canada, is said to be the first comprehensive, quantitative synthesis of app-based interventions across various health outcomes and non-communicable disease metrics in adults
They reported that apps consisting of lifestyle or progress tracking, educational components such as content, guided programs, and tips, as well as interaction with health-care professionals or community were key to achieving improvements in health outcomes
App-based health tracking, however, did not result in significant effects on other outcomes such as fruit and vegetable intake, reduction in cholesterol levels, triglyceride concentrations, body fat, hospitalization, cardiovascular disease mortality or distress
For such changes to take effect, the researchers believe that more intensive, multifaceted strategies involving diet, medication, or clinical programs are needed
“App-based interventions did not have a significant effect on lipid profiles, total cholesterol concentrations, fruit and vegetable intake, smoking abstinence, and body fat—outcomes that typically require more intensive, multifaceted strategies involving diet, medication, or clinical programs,” the researchers wrote
For example, the researchers argued that improvements in body weight but not body fat percentage could have resulted from limitations to the duration of intervention, or the focus of app features on general activity rather than fat-loss strategies
“The observed weight loss could reflect changes in water content or lean mass rather than fat mass, as reductions in body fat typically require longer-term or more intensive interventions. Because most studies did not report mechanisms, further research is needed to clarify these differential effects,” the researchers wrote
To determine the impact of health tracking apps, researchers analyzed 78 meta-analyses and systematic reviews on 496 primary studies
Most of the 496 studies were conducted in Asia (35%), followed by North America (28%), Europe (24%), Oceania (10%), South America (2%) and Africa (1%)
Upper-middle-income countries contributed 24% of studies, with the largest number being conducted in China at 21%
These studies were sieved from eight databases, including Embase, Epistemonikos, IEEE Xplore Digital Library, APA PsycInfochrane Central Register of Controlled Trials
During the umbrella review, researchers analyzed the effects of health tracking apps on 31 health outcomes
The certainty of evidence for each health outcome was also assessed, ranging from high quality to critically low quality or from highly suggestive to non-significant, depending on the framework and criteria used
Of the 31 health outcomes, five were reported to have yielded highly suggestive evidence, namely 2h postprandial glucose concentration, fasting blood glucose concentration, HbA1c, medication adherence, and mindfulness
Eight outcomes, including diastolic blood pressure, systolic blood pressure, stress, body weight, diet quality score, waist circumference, multiple physical activity, and number of steps taken, were said to possess “suggestive evidence.”
Eleven outcomes, namely cardiovascular disease mortality, anxiety, depression, distress, wellbeing, BMI, fruit and vegetable intake, exercise capacity, moderate-to-vigorous physical activity, sedentary time, and quality of life, were said to have weak evidence
The remaining seven outcomes, namely HDL, LDL, total cholesterol, and triglyceride concentrations; hospitalization; body fat; and smoking abstinence, were said to have “non-significant” evidence
“To our knowledge, this is the first umbrella review that systematically maps and categories app features, offering a structured framework with which to understand which components of the apps drive their effectiveness…” the researchers wrote. “Our conclusions are supported by a mainly autonomous body of evidence, encouraging the broad applicability of our findings.”
A limitation of this umbrella review lies in the quality of the studies analyzed
The researchers acknowledged that most systematic reviews used in the review were of low quality based on the AMSTAR 2 appraisal tool, with frequent issues such as an absence of published protocols, an unsatisfactory risk of bias assessment, and poor reporting
“Most primary studies were rated as having a high risk of bias, largely due to a lack of masking; this is an inherent challenge of app-based interventions unless the control group uses alternative apps,” the researchers wrote
In this umbrella review, the certainty of evidence was rated from “highly suggestive” to “not significant”, which aligned with a previous umbrella review on prescribable apps that had been tested only in pilot RCTs with small samples and short durations
“These factors underscore the need for larger, methodologically rigorous trials and high-quality systematic reviews to strengthen the evidence base and clarify the long-term effectiveness of app-based interventions,” the researchers wrote
Future studies could also assess the effectiveness of health tracking apps in improving neurological, digestive, alcohol use and sleep disorders
