Interventions to increase physical activity and reduce sedentary behaviour in severe mental ill health: How effective are they?'- A systematic review

Background: People with severe mental ill health experience a mortality gap of 15-20 years and one of the main reasons for this is due to preventable physical health conditions. Physical activity can reduce the risk of developing physical health conditions such as diabetes and cardiovascular disease yet people with severe mental ill health are less physically active and more sedentary than the general population. Methods: A systematic review was conducted to investigate the effectiveness of interventions aimed at increasing physical activity and reducing sedentary behaviour in people with severe mental ill health. The protocol was published with PROSPERO (CRD42021277579). Randomised controlled trials conducted in any country in any setting and published in English with an aim of increasing physical activity or reducing sedentary behaviour were included. Results: Eleven unique studies were identified for inclusion. Due to the variability between interventions, outcome measures, and time points, it was not possible to conduct a meta-analysis. Effect estimates suggested that three of the interventions were effective at increasing physical activity. However, the certainty of the evidence was rated as low using the GRADE approach. Conclusions: The evidence on interventions to increase activity shows promise but is insufficiently robust for an intervention to be recommended in clinical guidelines. More high-quality and statistically powered trials are needed to guide best practice and policy.