Title: Complex Evidence Synthesis using Network Meta-Analysis, IPD and Multiple Outcomes: Application Investigating the Effectiveness of Pragmatic Interventions for Diabetes Prevention and Interventions to Increase the Use of Childhood Accident Prevention Practices in the Home.
Funder: Department of Health and Social Care

Abstract: BackgroundPublic health appraisals usually are informed by simple evidence synthesis methods. These methods do not address some of the key challenges where the interventions are more complex and not as well defined as they are in controlled trials. Interventions that are made up of components are termed as complex interventions', for example, interventions to reduce obesity might contain diet' and exercise' components. Particular combinations of components may be more effective and cost-effective for subgroups of the population. Individual participant data and the simultaneous synthesis of multiple outcomes are rarely used in evidence synthesis but have the potential to reduce the uncertainty in the intervention effect estimates and to help appraisers make better decisions in relation to their effectiveness and cost-effectiveness. Aims The aims of this project are to answer the following research questions:How can complex interventions be assessed to provide better information to decision makers about all possible interventions?How can the evaluation of complex interventions make use of all available data to inform tailored decision making for subgroups of the population?How can the simultaneous evaluation of multiple outcomes for complex interventions improve the evidence base for decision makers? MethodsA search will be undertaken to determine what current methodologies are available for analysing complex interventions. A review of NICE public health appraisals will identify studies where the use of more sophisticated methods may have been appropriate but were not implemented. Evidence synthesis methodology will be developed to include individual participant data into a complex intervention network meta-analysis model and this will be further extended to include multiple outcomes. The performance of the methods will be assessed using simulation studies as well as two case studies in diabetes prevention and increasing the use of childhood accident prevention practices in the home. This will include investigating the value of the added information in relation to individual participant data and multiple outcomes. Anticipated Impact and DisseminationThese methods will have the ability to use all of the information available in evidence synthesis research and improve the precision of the effectiveness estimates of public health interventions. These methods can be translated into a range of clinical and public health evidence synthesis situations where the interventions or treatments are complex. This will provide better information for health intervention appraisers to make better decisions that will improve patient outcomes, improve the efficiency of health appraisal research and enable more efficient allocation of scarce NHS resources. The dissemination plan for this project includes the submission of papers to leading journals with short video abstracts, the involvement of the patient and public group to feedback the results to their clinical and wider networks and presentations at national and international conferences. A multi-stakeholder workshop will be organised in the final year to present the results of the project.

Lay abstract: Aims of the Research: Doctors and healthcare providers often advise the public to take actions to improve and prevent health issues. For example, doctors may advise that a patient at risk of obesity takes action by following an exercise regime' to reduce this risk. Multiple actions may be advised at the same time. For example, a doctor may advise that a patient at risk of obesity takes action to reduce this risk by having a low fat diet' as well as following an exercise regime'. The multiple actions that are advised often vary depending on the situation and it can be difficult to decide which actions are best or whether combinations of actions should be advised. The actions that are taken to improve or prevent a health issue can often have multiple benefits. For example, low fat diet' and exercise regime' can help to lower the risk type 2 diabetes as well as lower the risk of obesity. This project will look at two major health issues in the UK: type 2 diabetes and childhood accidents at home. For these two health issues, this project aims to answer: From the actions that are already recommended, which actions or combinations of actions work better than others? Are some actions better in certain groups of people? What actions should be advised to make sure that all of the benefits are maximised? This project will focus on developing statistical methods that can be used to answer the aims above. These methods will help the NHS to make better choices about which actions to advise to which people. This could lead to better care, improved public health, and help to allocate limited NHS resources. Background: Doctors and healthcare providers decide which actions improve and prevent health issues. Decisions are based on the results of past research and so statistical methods are used to combine the results from many sources to improve the decision. The statistical methods that are currently being used do not consider actions or combinations of actions that are not looked at in the past research and so might miss the best combination of actions. This might mean that the public do not receive the best advice to improve or prevent their health issues. Design and Methods: Information will be gathered from previous research on multiple actions for type 2 diabetes and childhood accident prevention. I will improve statistical methods so that every action and combination of actions is evaluated to find out which is the best. The methods will include potential combinations of actions that might have been missed with the current statistical methods. The statistical methods will also be improved to find out which actions are better in which groups of people and consider all the benefits of the actions. Public Involvement: The advice and input of the public is needed throughout project planning, progress and sharing of the results. Members of the public have read and advised on the project proposal. The public group will advise which benefits of the actions are most important to them. They will be invited to give their take on the results, share the results in their wider networks and take part in the final workshop. Publicising the Results: Papers describing the statistical methods and their use in the two major health issues will be written for journals. Programming code will be shared to encourage other researchers to use the methods. The results will be presented at a workshop at the end of the project.

Research activity codes: 7.3 MANAGEMENT AND DECISION MAKING
Health categories: METABOLIC AND ENDOCRINE