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  • Writer's pictureChristie Roberts

Prevention in Public Health

I know it, you know it, we all know it, so say it with me...


The mantra chanted by many a public health professional, but what does it actually mean and how do we do it?

The World Health Organisation (WHO) define disease prevention as specific, population based or individual based interventions aiming to minimise the burden of disease and associated risk factors (WHO, 2024). It goes hand in hand with health promotion and consideration of wider determinants of health, and it essentially fulfils the definition of public health- 'the science and art of preventing disease, prolonging life and promoting health through the organised efforts of society' (Faculty of Public Health, no date).

It can be broadly split into 3 main types of prevention:

Primary prevention

This incorporates actions taken to reduce the incidence of disease- so to prevent anyone from getting unwell in the first place. This can include universal measures which might address increasing immunity, through vaccinations, or modifying lifestyle factors, such as ensuring that everyone has a healthy diet and gets the recommended amount of exercise, as well as targeted measures that impact on specific high-risk groups, such as the use of Pre-Exposure Prophylaxis (PrEP) for gay, bisexual, and other men who have sex with men (GBMSM) to prevent HIV. Either way, the target audience is healthy people who do not yet have the disease. Primary prevention is sometimes referred to as an 'upstream' approach (more on this later!) and is a proactive approach to managing disease.

Secondary prevention

This could be considered a form of harm reduction, as it is aimed at people who appear healthy, but potentially have subclinical forms of disease or pathological features which could lead to them becoming unwell. Secondary prevention seeks to pick up on early signs of disease and intervene before symptoms develop. Examples include use of medications, such as statins to reduce cholesterol and hence reduce the risk of stroke or heart attack, and screening programmes which seek to promptly identify changes and can either lead to treatment or enhanced screening. Cervical cancer screenings (smear tests) are a good example- if no abnormal changes are found, screening continues 3 yearly but if HPV and/or abnormal cells are detected, screening then occurs yearly or additional tests such as colposcopy may be ordered (NHS, 2023). Through regular screenings, pathological changes are picked up quickly and monitored to ensure that any changes do not progress into disease. Early detection leads to early treatment, and improved outcomes.

Both primary and secondary prevention aim to prevent the onset of disease, but what happens if disease has already progressed? Additionally, some illnesses, like genetic or autoimmune conditions, are not necessarily preventable. Which leads us to...

Tertiary prevention

A form of preventative care aimed at individuals who are already symptomatic or living with an illness. Typically, these will be long-term and often complex conditions. Intervention and support should aim to improve functioning, maximise quality of life, and maintain life expectancy to as close to average as possible. Where possible, the severity of a disease will be minimised and prevented from progressing, along with avoiding any sequelae from the original disease. An example of this could be people living with HIV taking antiretroviral medication to suppress their viral load and avoid the condition progressing into AIDS.

Another example- I personally have type 1 diabetes. As this is an autoimmune condition, there is nothing that could've been done to stop me from developing the condition at 8 years old. But, tertiary prevention plays a part in helping me to live well and reduce symptom burden and incidence of any complications. I attend frequent reviews to check on my management of my condition, and I attend yearly eye screenings and foot checks to screen for development of diabetic retinopathy or peripheral neuropathy. This way, the impact of diabetes on my life is minimised, the sequelae of diabetes are avoided, and my quality of life and life expectancy are maintained.

The Upstream model

There are various parables in public health that revolve around rivers, and prevention fits nicely into this. I mentioned earlier that primary prevention is known as an 'upstream' approach. These are interventions that stop people falling into the river in the first place, compared to a 'downstream' approach of fishing people out once they're already in and drowning. I've tried to illustrate this, along with some of the approaches that fit, in the image below (Microsoft should sponsor me for the amount of diagrams I make using Paint)

An upstream approach typically has impacts on a community, whilst downstream interventions are more focused on individuals. I've linked a video below that sums up this approach nicely:

Examples of prevention methods


  • Immunisations

  • Prophylactic medications- for example, PrEP for HIV, or antibiotics to prevent potential post-operative infections

  • Health and social care policy designed to make health the easiest option- this links to a 'Health in All Policies' approach (post on this coming soon!!)

  • Increasing health literacy and providing education- generally around lifestyle factors like diet, exercise, smoking, and alcohol.


  • Lifestyle modifications- for example, maintaining a healthy weight to prevent someone from becoming obese, or helping people to lose weight if they are already obese to reduce the risk of weight-related issues.

  • Screening and monitoring programmes- for example, seeing people regularly to identify risk factors and modify these where possible before they cause problems, or detecting subclinical signs of disease early to allow for earlier treatment and better outcomes


  • Medications- for example, preventer inhalers with steroids to prevent people with asthma from having regular asthma attacks.


  • Rehabilitation to regain function or prevent further deterioration- for example, PT, OT or SALT input post stroke.

  • Support groups to maintain mental health and wellbeing- for example, for people living with cancer, who are at higher risk of depression, anxiety and distress due to their diagnosis (Niedzweidz et al., 2019), which may impact on quality of life.

  • Ongoing monitoring and screening for complications

  • Medications- for example, disease modifying antirheumatic drugs (DMARDS) for arthritis, which can slow disease progression and provide symptom relief.

The benefits

A preventative approach to improving health really is a win-win for everyone involved. The benefits include:

  • Improved health for individuals

  • Improved health for communities

  • Improved quality of life for all

  • Decreased capacity burden on health systems- this is somewhat of a double edged sword. We've got so good at treating people for ill health that people are now living longer, contributing to an ageing population who may have increased support needs, and are living with more complex and chronic diseases, which require ongoing monitoring. The better we get at treating people, the more people we have to treat (unless we can prevent people getting sick in the first place!!!)

  • Decreased NHS spending on treating ill health, and the consequences of ill health

  • Improved productivity and a healthier workforce, who can contribute to the economy (I hate making this point, because people's lives are more than just being able to be part of the workforce and it implies that people who cannot work for a litany of reasons are less valuable as people, but it is still a valid point)

The challenges

The challenge of implementing preventative health is that it often requires a shift from a reactive system of healthcare into a proactive system. I would describe the NHS as a very reactive model, in that we are great at treating conditions, but pretty poor at avoiding them in the first place (this isn't down to the NHS alone, it's the result of a culmination of systems which are designed to support health, such as social policy and our built environment). In order to make a much needed pivot to preventative care, which would reduce financial and capacity burdens on the NHS and allow it to keep functioning as a system, we need investment. Investment needs money and time and political will, none of which are in great supply within current systems.

A period of time where both proactive and reactive care are in play would be required- 2 concurrent systems would require 2 times the money and resource and unfortunately, we don't have the money or resource to achieve that (as much as I love the NHS, I'd go so far as to say we currently don't even have the money and resource to fulfil our currect reactive approach).

Outside of big scale approaches, there's a lot we can do to help people help themselves. Increasing health literacy ('the personal characteristics and social resources needed for individuals and communities to access, understand, appraise and use information and services to make decisions about health... includes the capacity to communicate, assert and enact these decisions'- Health Education England, 2020) and providing accurate and relevant education to empower people to make healthy choices and maintain their health. How will people protect their children against communicable diseases if they don't know what vaccinations are recommended, when to get them, or how to get them? How do we combat the high (and seeminly rising) levels of vaccine skepticism driven by misinformation and lack of knowledge?

As an example, vaccination with the MMR (measles, mumps and rubella) vaccine has been suboptimal in the UK and falling short of the 95% coverage target required to achieve herd immunity. In 2022/23, MMR vaccination coverage for first and second doses sat at 85.2% (Harker, 2024) and the effects of this have been seen in outbreaks across the UK. In the entirely of 2023, there were 362 cases of measles confirmed in England (UKHSA, 2024a). By May 2024, there has already been a staggering 1352 cases reported in England (UKHSA, 2024b).

The reasons for declining vaccination rates, and hence the spiralling outbreak rates, are likely to be multifactorial and differ based on geographic and social variances, but improving public health messaging about the importance of vaccination should act as a cornerstone in implementing preventative care. In the case of MMR vaccines, I feel Wakefield still has a lot to answer for...

Accessibility to resources needed to promote health can also be a stumbling block. People need to be able to access the tools and services designed to help them improve their health. Typically, this is related to modifiable lifestyle factors. Initiatives like subsidised gym memberships can be a great idea, but is it accessible to everyone who would benefit from it? For example, do parents have adequate childcare that would allow them time to get to a gym? Is the gym on suitable public transport routes, so that those who don't drive can actually get there? Do the opening hours of the gym or timings of classes work for people who work long shifts or antisocial hours?

This seems to be ending on somewhat of a bleak note, because I don't have an answer nor quick fix for how we overhaul our entire health and social care systems to better protect population health through prevention. What I do know, is that we have a growing public heath workforce who are committed to making changes, we have an upcoming generation who appear to be more politically aware and justice motivated than ever, and that individuals can make a difference. It may be on a small scale, but a difference is a difference.

If a public health practitioner can support one patient to drink alcohol in line with national guidance, you are potentially preventing someone from developing alcohol-related liver disease.

If a doctor can educate one patient on the importance of condom use, you are potentially avoiding someone from contracting and spreading sexually transmitted infections.

If a nurse can convince one patient to come in for a cervical screening, you are potentially allowing cell changes to be picked up before they develop into cancer.

If an occupational therapist can support one patient to join a walking group, you are potentially preventing someone from becoming isolated, whilst also improving their physical fitness.

It all adds up, and little differences combine to make big differences to individuals and communities.

I'll leave you with one of my favourite quotes, from Desmond Tutu, which really sums up the importance of primary prevention in protecting population health:

Remember kids, health is wealth, and prevention is better than cure.

All my love,

Christie x


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