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.

This chapter considers the major causes of mortality and morbidity for adults and describes the significant burden of these non-communicable diseases, their risk factors and potential public health action. While the conditions discussed are relevant to other age groups, those included – cancers, cardiovascular disease, diabetes, obesity, mental health problems and long COVID – have particular relevance for the large proportion of the population of working age. This chapter also focuses on specific actions or policies which can be employed to address each of these non-communicable diseases.

At the core of epidemiology is the use of quantitative methods to study health, and how it may be improved, in populations. It is important to note that epidemiology concerns not only the study of diseases but also of all health-related events. Rational health-promoting public policies require a sound understanding of causation. The epidemiological analysis of a disease or activity from a population perspective is vital in order to be able to organize and monitor effective preventive, curative and rehabilitative services. All health professionals and health-service managers need an awareness of the principles of epidemiology. They need to go beyond questions relating to individuals to challenging fundamentals such as ‘Why did this person get this disease at this time?’, ‘Is the occurrence of the disease increasing and, if so, why?’ and ‘What are the causes or risk factors for this disease?’

The proportion of the population living into old age has been increasing worldwide. For the first time in history, there are more older people than children under 5 years of age. The task for public health is to understand the relationships between ageing, health and the environment (physical, social and economic) in which people live, to promote healthy ageing and prevent the disability and subsequent dependency that is often associated with growing old.

This chapter examines the factors that lead to ageing populations and explores the health, social and economic consequences of the change in the population structure. It then goes on to outline strategies that can lead to healthy ageing and other public health actions that could help to manage the challenges posed – and the opportunities afforded – by the relative and absolute increase in the number of older people.

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.

To effectively target public health interventions for greatest impact, it is essential that public health practitioners have a clear understanding of the populations they work with. As described in Chapter 1, understanding these populations, their health status and health needs draws on skills from several disciplines, including demography, epidemiology and statistics. Brought together, these skills allow the practitioner to understand the characteristics of the population of interest, the key health issues that it faces and the broader factors that have a particular influence on the health of that population. These broader factors are generally referred to as the wider determinants of health or the social determinants of health. Information is also vital in allowing practitioners to assess the impact of public health interventions.

Health-care systems within most countries are resource-limited – budgets are finite and not every service one would like to provide can be funded. In publicly funded health systems, those responsible for procuring health-care need to be able to explain how taxpayers’ money has been spent. Decisions are made at both individual patient and population levels. At an individual level, the decision might be: which statin should this patient get a prescription for to lower her blood cholesterol? At a population level, the decision might be: will a health and social care commissioning organization purchase a heart-failure specialist nurse or an additional sexual health clinic?

This chapter focuses on how such decisions are made and considers a framework for priority setting, a discussion of what factors should be taken into account when comparing options, a consideration of basic health economic concepts, and an overview of ethical principles which influence decisions.

Health protection refers to threats to health such as infectious diseases, environmental threats, natural hazards and threats from terrorist acts. Health protection may also overlap with action, tackling the determinants of health, especially legislative aspects such as workplace smoking bans or speed restrictions and even lifestyle choices and the health issues of ageing populations, such as increasing levels of chronic disease (which we now know may also be due to infections).

This chapter outlines the public health aspects of communicable disease control and touches on some of the other areas now included within health protection in the UK. Important health protection terms are included in the glossary.

Effective health-care makes a large and increasing contribution to preventing disease and prolonging life by reducing the population burden of disease. However, only the right kind of health-care delivered in the right way, at the right time, to the right person can improve health. Health-care interventions that are powerful enough to improve population health are also powerful enough to cause harm if incorrectly used. How can public health specialists know whether their interventions are having the desired effect? Clinicians can monitor the impact of their treatments on an individual patient basis, but how do we examine the impact of a new service? This chapter looks at what we mean by quality of health-care and considers some frameworks for its evaluation.

That differences in health outcomes exist between groups is unsurprising and, in some cases, seems subject to ‘natural law’. Such ‘common sense’, arguably unavoidable differences are termed ‘health disparities’ – a term usually understood to be value-neutral. By contrast, more complex differences in health outcomes which seem to derive from differences in opportunities or systemic bias are deemed ‘unfair’ and are referred to as ‘health inequalities’ or ‘health inequities’.

This chapter delves further into how we describe health inequalities and different measures and data that illustrate these differences. Causes and mechanisms of inequality are explored, followed by examples of inequality across groups with certain population characteristics, including ethnicity; gender, sexual orientation and gender identity; disability; and socially excluded groups. Finally, approaches and strategies for reducing health inequalities are presented, with potential actions described at the micro-, meso- and macro-levels.

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.

The first element of understanding how to improve the health and well-being of a population relies on a thorough assessment of the needs of the specified population, be it a local population defined by geography, a specific age group or those with certain characteristics. This chapter begins by considering how ‘health need’ can be conceptualized; the distinction between need, demand and supply; and the difference between health needs and the need for health-care. Secondly, the wider determinants of health are introduced and their relation to health needs discussed. Finally, the steps involved in a systematic assessment of the health needs of a defined population are explained, including tools and resources used to achieve this. Practical challenges are considered.

This chapter focuses on the interplay of health policy and politics at a national level, and:

• explores the process by which health policy is created and the context in which it is developed and influenced;

• considers the interplay between policy and its implementation; and

• offers a narrative of the evolution of national health policy and politics in England over the last 30 years.

This chapter starts by considering the key differences that make public health practice focused on children unique to that focused on adults and older people and emphasizes the importance of early intervention as part of a life-course approach. The demography of the health of children is detailed, followed by a description of the major causes of ill health in children and young people, key public health challenges for this age group and their families and a summary of effective public health interventions to improve health and well-being and reduce inequalities. Three case studies are offered: the impact of the COVID-19 pandemic; childhood obesity; and children’s and adolescents’ mental health. These highlight the complexity of these major public health challenges, how the tools described in Part 1 can be used to understand them and the importance of strategic and system-wide approaches.