Characterising patterns and changes in physical activity in older people and their determinants and consequences

Non-communicable diseases such as diabetes, heart disease, cancer and mental health problems account for 60% of deaths globally. Poor diet and lack of physical activity play an important role in increasing the chance of developing these diseases. Physical inactivity is estimated to account for around 1 in 10 deaths worldwide, comparable to the impact of smoking. In the face of these statistics it would seem intuitive that everyone should strive to make individual choices to adopt an active lifestyle. However, we do not make such choices in isolation and our activity levels are believed to be driven as much by the broader social, cultural, economic and physical environment in which we live by as our personal knowledge, attitudes and beliefs.

One of the main challenges that will face health services, and society, in the foreseeable future is the care of older people with limitations to their independent living. The promotion of physical activity among the middle-aged and elderly may make this challenge more manageable. Unfortunately, the majority of research on levels and patterns of physical activity, why some people are more active than others, and the links between physical activity and health outcomes has been undertaken among individuals less than 60 years of age, and has relied on imprecise questionnaire measures.

Our existing collaboration of scientists includes expertise in a range of disciplines from Public Health and Epidemiology, Health Geography and Health Economics to Social and Behavioural Science. We have worked effectively together for several years as part of a national Public Health Centre of Excellence called CEDAR (Centre of Excellence in Diet and Activity Research). CEDAR is a collaboration between Medical Research Council (MRC) Units in Cambridge, the University of Cambridge, the University of East Anglia (UEA) and non-academic partners including the East of England Public Health Observatory (ERPHO). CEDAR researches the determinants of diet and activity at the population level and develops and evaluates potential preventive interventions (see http://www.cedar.iph.cam.ac.uk/).

We have expertise in the causes of chronic disease, in physical activity and its measurement and in the development and evaluation of interventions to promote physical activity among individuals with or at high risk of disease. We also have access to a large population-based sample of older people participating in the EPIC-Norfolk study. In this project we will describe the levels and patterns of physical activity and also of sedentary behaviour (such as television viewing). We will study how these behaviours change over time using self-report and objective measures among volunteers in the EPIC-Norfolk study. We will also improve knowledge about the sorts of activities that might reduce risk of disease and be feasible for older people, the personal and environmental factors that influence physical activity in older people, and to what extent changes in physical activity might reduce disease risk and health service costs. These are important steps in developing interventions and policy to help populations adopt sustainable healthy behaviours.

In order to achieve our aims we will use a range of quantitative and qualitative research methods within the context of a large ongoing study. The evidence we gather will help politicians, health professionals and society at large make better decisions about how to improve health for the whole population, whether it is through direct public health interventions, or wider ways that influence how we live. It will also help scientists and research funders to focus efforts into areas in which reducing uncertainty through further research would provide the greatest benefit.

We aim to contribute evidence to inform the development of interventions and policy to promote physical activity among older people and shift population distributions of physical activity behaviour. We will achieve our aim through interconnected components employing a range of methods (quantitative, qualitative and modelling) in the context of an ongoing, large population-based observational study. EPIC-Norfolk, a prospective cohort study, recruited 30,000 men and women aged 40-79 years at baseline (1993 to 1997) from 35 general practices in Norfolk. Participants have completed the previously validated EPAQ-2 physical activity questionnaire on two occasions and one round of measurement of potential determinants of physical activity by a modified NEWS questionnaire (Neighbourhood Environment Walkability Scale with inclusion of additional items based on the Theory of Planned Behaviour). In addition, over 4000 participants have undergone objective measurement of physical activity by accelerometry.

The EPIC-Norfolk 4th health check has recently commenced, supported by MRC core funds, and includes measures of anthropometry, body composition and spirometry, a physical performance battery and self-report and objective (accelerometry) assessment of physical activity. In this project we will use home addresses (available for all participants) to derive detailed characterisation of the environment using standard geographical information systems. We will also add tracking of participants' location and movements using GPS devices and qualitative interviews. This will enable us to better understand the levels and patterns of physical activity and sedentary behaviour, the change in these behaviours over time, and the determinants of these behaviours and their health consequences. We will also develop a Markov model to quantify the impact of changes in population patterns of physical activity on health outcomes.

Immediate and medium term impacts: Research findings from this project are relevant to many aspects of the physical, social and economic environment. Relevant policy areas include travel and transport, use of green spaces, health and social care. We will contribute to the evidence in these areas and directly influence practice and policies at local, regional, national and international level, as well as via bodies such as NICE and Public Health England. This will be achieved through existing and new relationships ranging from exercise referral scheme coordinators to senior civil servants.

Trade unions, NGOs, and campaigners represent other potential audiences for our evidence outputs and may present research opportunities (eg the on-going evaluation of the Sustrans Connect2 initiative). NGOs are increasingly involved in service delivery. Our findings could help them to provide better services and lead to a stronger evidence base for their work. Our evidence is also relevant to industry. Findings may inform the Responsibility Deal in physical activity and interventions to encourage active travel and physical activity will be relevant to improving workforce health. Beyond the application of evidence, our expertise can be applied to enhance the effectiveness of evaluation of complex public health interventions - a requirement from local to international levels.

We recognise that impact is a 2-way process, with our research priorities shaped by public health needs. We will therefore continue to pursue a partnership approach, co-producing tools and publications and working closely with public health practitioners. Our work developing research and evaluation methods, such as the use of GPS technology, has applications beyond academia as organisations seek to effectively measure interventions. Partnership working will also help to support the research and evaluation capacity of organisations through, for example, contributing to training courses and material delivered through bodies such as ERPHO in its role in Public Health England.

Policy makers will benefit directly from the results of modelling and through using the models to consider different policy scenarios and assess proposed changes. The models will improve the ability to predict likely effects of interventions before deciding how to invest resources in real interventions; a major benefit for resource constrained public authorities. The move of public health functions into local authorities in 2013 will bring together responsibilities for transport and health. This research can provide evidence based on integrated rather than 'silo thinking'.

Longer term impacts: Our longer term economic and societal impacts will come from the implementation of policies that have been influenced by our research. Increased physical activity has substantial potential population health benefits by reducing the burden of non-communicable disease. Moves towards active and sustainable transport can bring environmental and health benefits including reduced road traffic deaths, improved urban environment, and mitigation of climate change. These benefits would be felt by governments, both economically and in terms of the effectiveness and sustainability of public services such as the NHS. Employers and industry can also draw benefits from population-level interventions, through improved employee health, wellbeing and efficiency. In England, the costs of lost productivity have been estimated at £6.5 billion / year from sickness absence and premature death. However, physically active workers take 27% fewer sick days. This issue will become increasingly relevant to those aged 60 years and over as the retirement age rises. Finding effective interventions to improve activity levels will ultimately benefit the whole population, in the UK and abroad, in terms of health, wellbeing and quality of life.