Effective public health practice requires a combination of expertise and influence. Yet gaining expertise in the subject matter is only one element of practice: the ability to influence outcomes, policy, services and the people who make decisions is crucial. To deploy your expertise to have an impact, you must hone leadership and management skills to persuade, encourage and empower others. This chapter, therefore, aims to:

• offer a brief overview of different schools of thought in leadership;

• propose a simple framework of eight core domains for identifying skills and areas for professional development;

• introduce some popular theories for understanding others, which can enable you to work more effectively with individuals and influence within teams and organizations; and

• signpost to some key models of conceptualizing change and how to lead or manage change.

Screening is an important preventive public health activity. This chapter:

• provides examples of effective screening programmes;

• considers what criteria are needed to demonstrate the effectiveness of a programme;

• describes how screening tests can be used to guide action; and

• describes how screening programmes can be evaluated.

Public health cannot be understood or fully appreciated without some knowledge of its history, which this Introduction provides. Conventionally, this begins with the large body of work associated with Hippocrates (c. 460–370 BC). In these writings, health was viewed as resulting from a sound balance of the humours. Therapy included diet, exercise and other interventions tailored to the individual – akin to today’s emphasis on healthy living and lifestyle. The Hippocratics were, in addition, early exponents of environmentalism. In Airs, Waters, Places, the occurrence of disease was linked to such factors as climate, soil and water quality. Proposals for disease prevention were related to specific social and economic circumstances.

The causes of ill health and death are changing and, as we live longer, new health-preventable problems emerge, bringing new challenges. Improving health (physical, mental or both) and promoting general well-being remain major priorities.

Just as important, the difference in health status between rich and poor continues to grow. At a global level, the picture is even more complex. Although there is some evidence that life expectancy is beginning to plateau in developed countries such as the UK, the biggest potential to improve health still lies in addressing inequality between or within countries.

Therefore, this chapter:

• summarizes the models of health improvement that are prevalent today;

• introduces a combined conceptual model to describe the factors affecting health in modern times; and

• presents some case studies of interventions designed to improve health which offer important insight and learning.

As we discussed with regard to leadership in Part 1, the context in which the public health tools are used has a bearing on the choice of tool and how it is implemented. In the second part of Essential Public Health: Theory and Practice, we consider a range of contemporary contexts in which public health is practised and illustrate how the tools we have described are applied.

The Morris Justice Project (MJP) works in an area of New York City that is internationally renowned for its place in urban music and culture as much as the stigma that is associated with its reputation. MJP is an informal collection of collaborators and, through its members, is connected with an academic institution. The Project engaged in research-driven activism which attempted to change aggressive community policing methods. One core idea was to use participatory action research methods to generate fresh data on the official policy of ‘stop and frisk’ of residents who were seen as suspect by police. This data was then discussed with a wider set of local people, and used by MJP as part of a city-wide movement for reform of New York Police Department's ‘Broken Windows’ and ‘zero tolerance’ policies. Theirs is a powerful and uplifting story of community mobilisation for social justice.

With 12 authors actively involved in producing and editing, this writing team is itself an example of co-produced knowledge from the start of the inquiry through to and including writing this contribution. It is an illustration of what it could mean for all parties to take seriously multiple forms of expertise. This is not only about elites or professional experts respecting lived expertise, but includes community experts advocating the value of research, or what one participant in the MJP describes eloquently as ‘coming from a place of knowing’.

The Morris Justice Project brought together a diverse collective of academics, lawyers, artists, activists and residents of a South Bronx neighbourhood outraged by New York Police Department's (NYPD) aggressive use of ‘Broken Windows’ policing.

Key points

• Health promotion focuses on the social, economic and environmental determinants of health and aims to help people increase control over their own health.

• Many different groups and organisations are involved in health promotion within and without the NHS for it encompasses health policy, education, legislative action and community development.

• Disease prevention at the level of the high-risk individual is increasingly effective but population-wide approaches have greater potential to improve population health.

• Psychological models of behaviour change can support both individuals and organisations to improve health.

Disease prevention

Cervical cancer is 20 times more common in Columbia than in Israel. Twenty percent of Afghan children die before the age of 5, compared with 0.5% of children in the UK. Ischaemic heart disease death rates vary by a factor of two in different wards in Luton. In other words, diseases that are common in one place will usually prove to be rare somewhere else. Such variations suggest that common diseases – with their roots in lifestyle, social factors and the environment – are preventable but there are several misconceptions about prevention.