Population Health

Population Health

Today your activities will focus on the science of Population Health. When you hear the term “health”, you probably think of hospitals and GP surgeries, and the ways we get better from illness. That’s a part of healthcare, but managing the health of populations requires an approach which takes account of the various factors which contribute to our physical, mental and emotional wellbeing. It recognises that some people will rarely have any contact with traditional healthcare at all, whilst others will have chronic conditions which can’t simply be fixed, but everyone has needs to enhance their wellbeing.

Watch the video below and note down why you think preventing, rather than just treating, illness, and thinking about the population as a whole, might be preferable for:

  • Individuals
  • Healthcare professionals
  • Governments

So how do we measure the success of an approach to healthcare? Healthcare professionals use the term health outcomes to describe the effects of their care on individuals. Positive health outcomes include an extended lifespan, being cured or having a physically-improved condition, functioning well socially and emotionally and being in work. Research estimates that only 20% of a person’s health outcomes can be attributed to the ability to access good quality healthcare.

Now that you understand the concept of population health, we are going to look at three areas in which scientists are working to predict and prevent illness, and develop better treatments, in order to improve the quality of life and happiness of populations.


Epidemiology is the study of patterns of disease and health conditions within populations, and their causes. A population health approach to epidemiology is particularly concerned with understanding how often and how seriously disease occurs in certain subsections of the population, which allows governments and healthcare professionals to plan more targeted and effective treatment and prevention measures.

In the video below, Dr. Pardis Sabeti explains how epidemiologists use scientific models to predict the course of an outbreak of disease and plan possible interventions. Watch the video and then try the quick quiz below.

Activity: Quick Quiz!

  1. What is the difference between a variable and a parameter?
  2. Which three groups does the SIR model take into account?
  3. What three assumptions does the SIR model make about the relationship between these groups?
  4. What is the value of the reproductive number, R, at the peak of an outbreak, and why is this a turning point?
  5. What other group might we add to the SIR model to make it a more realistic model of the spread of disease?
Check your answers by clicking this tab
  1. What is the difference between a variable and a parameter?

Variables are aspects of the situation you are trying to model that are changed depending on the circumstances. Aparameter is a fixed number from data or assumptions about a situation.

  • Which three groups does the SIR model consider?

People susceptible to a disease

People currently infected with the disease

People who are removed from the model because they’ve already had the disease or sadly died and can’t become infected again.

  • What three assumptions does the SIR model make about the relationship between these groups?
  • Interaction between susceptible and infectious people can cause susceptible people to become infected. The number of susceptible people therefore declines over time.
  • The number of people removed from the susceptible group is the same as the number of people added to the infected group.
  • After people have been infected for a while, they move to the removed group because they’ve recovered or sadly died.
  • What is the value of the reproductive number, R, at the peak of an outbreak, and why is this a turning point?

At the peak of an outbreak R = 1. It is a turning point because more people begin to recover than become infected so the total number infected begins to decline.

  • What other group might we add to the SIR model to make it a more realistic model of the spread of disease?

We could include those who are “exposed”, those who have the disease but can’t transmit it to others.

Activity: Disease Detective

Epidemiologists use modelling to plan their interventions and reduce the impact of outbreaks of disease. But exactly what strategies can they deploy to tackle an outbreak? We’ve all become familiar with some of the ways in which governments manage the spread of disease in populations, through our experience of the Covid-19 pandemic.

In this fun game you’re going to experiment with how the early stages of an outbreak look from the perspective of epidemiologists, and some of the strategies they use to understand the spread and respond to it, focussing especially on travel and contract tracing. The sooner you identify where the first person caught the illness, and how it’s spreading, the quicker you can stop more people becoming infected! Have a go at a couple of missions and then return here to continue with today’s activities.

Managing a nation’s mental health

The nation’s mental wellbeing is an essential part of public health. A key misconception is the idea that mental health is always a problem, and only affects some people. A population-based approach recognises that everyone has mental health, just as we all have physical health, and we can encounter a whole spectrum of challenges with it. As with physical health, then, population health seeks not only to improve treatment for those with serious mental health illnesses but also to prevent illness and to care for the mental wellbeing of everyone. In 2011, the government announced a new mental health strategy, which was welcomed by the sector. However, since then there have been signs that the number of people suffering mental health issues still far outstrips the capacity available, a problem only worsened during the Covid-19 pandemic. We’ve linked a recent government press release below which announces new investment in mental health and some of its strategies. What do you think are the strengths and weaknesses of these plans?

Reducing Health Inequality

Health inequalities are the imbalances in health outcomes between different groups. We know that certain communities are disproportionately impacted by disease, and if governments want to improve the health of whole populations, they must tackle these inequalities. Here are some statistics which illustrate this reality in the UK:

  • In Luton, a man from the poorest area will on average die 9 years earlier than a man from the wealthiest area.
  • Women with a learning disability in England average have a life expectancy of 65, 18 years lower than the national average.
  • In Bedford, just 12% of people with serious mental ill health are in work, compared to 76% of the general population.
  • In Luton, the life expectancy for a homeless woman is 41, 40 years less than the national average of 81.
  • The death rate from Covid-19 was twice as high for people in the lowest socioeconomic groups and from Black, Asian and Minority Ethnic communities than for wealthier and White British people.

What factors do you think might contribute to these inequalities?

Access to traditional healthcare certainly plays a role. Whether there are hospitals and GP surgeries in an area, and how easily accessible they are by public transport, can change the extent to which people engage with healthcare. Homeless people without a fixed address might be unable to access healthcare, and have often become disillusioned because they have been taught over many years that the system doesn’t care about them, so they will stay away from healthcare.

Broader cultural factors play a role too. During the Covid-19 pandemic, healthcare professionals worked with Muslim communities to gain their trust and show the vaccines available were not only safe and effective but supported by certain Islamic scholars. Sociologists have demonstrated how the stresses of living in poverty can shorten lifespan, as well as leading people on average to tend more towards unhealthy behaviours like drinking and smoking as coping mechanisms. LGBTQ+ people are much more likely to suffer from mental health issues due to cultural marginalisation and oppression.

Clearly, the healthcare system cannot resolve these problems alone. For that reason, solving health inequalities is a multidisciplinary priority for professionals across many sectors. Watch the video below, in which Dr Owen Williams OBE describes the work of the NHS Health Inequalities Expert Advisory Group and the eight urgent actions which it identified.

Going Further

If you’d like to learn more about this plan to tackle health inequalities in the NHS, click here and read section 1 of this report (page 2 to page 10). The section sets out the eight actions, how they will be approached, and how success will be measured, in more detail.

Global Health Inequality

Health inequalities can become even more stark when you begin to compare whole nations. Watch the video below in which Hans Rosling shows the development of vast inequalities in health and wealth between nations over the past 200 years.

ACTIVITY: Make your voice heard!

The UN’s Universal Declaration of Human Rights declares that there is a fundamental right to health and wellbeing. (Article 25 – click here to read it for yourself). Do you think this human right is currently being met fairly for everyone? Some people think the prevalence of health inequality means this human right is not being met.

For this activity, you should design a sign for display on a protest or demonstration, raising awareness of the global health inequalities Hans described and demanding more co-operation between nations to equalise healthcare. You might include some of the following:

  • A slogan or play on words about the need to tackle health inequality
  • Drawings
  • Statistics from the video

 Your sign should be eye-catching enough to get the attention of bystanders, and informative enough that they can easily understand what the protest is about!

Going Further

If you enjoyed learning about global health inequality, you can find the data Hans uses by clicking here and experiment with it for yourself.

Emmet O'Leary
Emmet O’Leary

Emmet O’Leary studied History at St John’s College, Oxford. Whilst studying he spent time as JCR Class Rep, promoting the interests of students from under-represented socioeconomic groups and later as President of the Junior Common Room (JCR). His undergraduate thesis explored the impact of Famine in Ireland, and its demographic shockwaves, on cultural and religious practice in the nineteenth century. He has wide-ranging historical interests including the writings of the Enlightenment and the social upheavals of the European Reformations and is also keenly interested in constitutional law and its connection to current affairs. Emmet is currently Access and Outreach Intern at St John’s.