• urban residential areas
• longitudinal study
• senior citizens

For some time epidemiology has been criticised for focusing almost exclusively on individual disease risk factors. Thus Shy¹ maintains that academic epidemiology has served clinical medicine well because of its narrow biomedical perspective, dealing with risk factor and disease associations, rather than contributing to a population understanding of disease patterns. Others have been critical of this biomedical individualism and pointed to the lack of social, economic, environmental, and political analysis.^2,3 In particular Rose has urged the need to recognise the crucial but subtle difference between sick individuals and sick populations. He suggested that epidemiology should understand disease as a consequence of how society is organised and behaves, what impact social and economic forces have on incidence rates, and what community actions will be effective in changing incidence rates. Epidemiology has been the main scientific method of public health and criticism of its individualism has led to calls for a new public health^4,5 that sees understanding the social, environmental, and economic determinants of health as crucial. Epidemiologists are beginning to respond to the needs of the new public health and to examine the impact of locational and environmental factors. Thus in terms of health inequities epidemiologists are examining whether these reflect purely the characteristics of individuals or their households or whether they may also reflect the particular contexts in which people live.^6,7 The paper by Takano et al⁸ looks beyond individual risk factors to features of environments and locations that affect health. This was done through a study of longevity in senior citizens that found a correlation between longevity (probability of five year survivial), whether they reported they had space for taking a stroll near their residence, parks, and tree lined streets near their residence. This correlation remained after controlling for the effects of the residents’ age, sex, marital status, and socioeconomic status. The findings from the paper by Takano et al are important for three reasons: they demonstrate how epidemiological methods can be adapted to research the structural factors that affect people’s health; they suggest that exercise patterns reflect the environments in which people live; and they contribute to an evidence base for health promotion initiatives based on settings such as Healthy Cities projects The first of these factors has been examined above; the other two are examined below.

Before the publication of the Ottawa Charter⁹ much health promotion put emphasis on changing behaviours of individuals. Many heart health campaigns were launched to try and persuade people to take up healthy behaviours. The results from these trials were largely disappointing and those who benefited tended to be better off and healthier people. For many people structural factors such access to healthy food, access to sporting facilities, or time limitation impeded lifestyle change. The paper by Takano et al provides important evidence that it is not individual motivation alone that determines willingness to take exercise but that the environments in which people live also have an effect.

The recognition of the limitation of behavioural health promotion has meant a greater focus on the settings in which people live, work, and play. Health promotion bodies, such as the National Heart Foundation in Australia, are moving away from a focus on the behaviour of individuals to look at the role of local environments in encouraging behaviours such as exercise.¹⁰ The WHO Healthy Cities movement¹¹ has advocated the importance of working with local governments to take a whole of community approach to health promotion. These projects put considerable emphasis on gaining political support and mobilising community action to ensure that health becomes a key consideration in city and community decision making. The initiatives offer particular challenges to evaluators. They are long term and aim to influence health by changing the way decisions are made to make environments more supportive of health. Attributing causality in Healthy Cities projects is extremely difficult so while process evaluations of the projects have been conducted outcome evaluation has proved more difficult. Work such as that presented by Takano et al is very important in building an evidence base for Healthy Cities and other projects. A body of evidence that shows the ways in which availability of facilities affects the extent to which people exercise can form the basis of healthy urban planning decisions and will make the task of health promoters easier.