Tag: Public Health

How achievable are the Conservative, Labour and Liberal Democrat pledges on the NHS?

The Conservatives, Labour and Liberal Democrats have set out ambitious plans for the NHS in their respective election manifestos. The challenge for the next government will be achieving targets in areas such as workforce and access to health services at a time when public sector finances are under severe pressure and there are calls for increased spending in many other areas.

Labour for example has pledged to recruit 8500 additional mental health staff but don’t provide much detail on how this workforce expansion will be funded. The Liberal Democrats have promised to recruit 8000 more GPs to ensure everyone can see a GP within seven days or within 24 hours for urgent needs. However, the recent decline in NHS GPs in England casts doubt on the feasibility of this pledge. The Conservatives propose cutting 5500 managers to save £550 million for frontline services. Yet, the NHS relies on managers to plan services, manage budgets and ensure compliance with healthcare standards. These cuts could inadvertently disrupt services rather than improve them.

All three parties pledge to take pressure off GP services by extending prescribing rights to other health professionals and expanding programmes such as Pharmacy First. While these initiatives aim to alleviate pressures on GPs, the impact of similar measures has been mixed. Without proper integration and support, such measures may not significantly reduce GP workloads. Pledges on public health and prevention in the manifestos are commendable. However, successful implementation requires appropriate funding, cross-sector collaboration, and long-term commitment to achieving these goals.

The essential role of daily exercise in enhancing health and well-being

Regular exercise is essential for good health, contributing to benefits that extend across the lifespan. In the United Kingdom, public health guidance emphasizes the importance of physical activity as a modifiable lifestyle factor that can significantly influence overall health and well-being.

Adults are advised to engage in at least 150 minutes of moderate-intensity activity each week, or 75 minutes of vigorous-intensity activity, along with strength exercises on two or more days a week that work all the major muscles.

Cardiovascular health sees marked improvements with regular physical activity. Exercise promotes heart efficiency, allowing it to pump blood more effectively, and reduces the risk of heart disease and stroke, which remain common health problems in the UK. Additionally, regular exercise can also help lower blood pressure and cholesterol levels, contributing to a healthier circulatory system.

Bones also benefit from exercise, particularly weight-bearing activities like walking, running, or resistance training. These activities stimulate bone formation and can help in reducing the risk of osteoporosis, a condition where bones become brittle and fragile. It’s especially crucial as one ages, because the risk of fractures and falls increases with age.

Mental health improvements are another significant benefit of regular exercise. Exercise can improve the symptoms of depression and anxiety through the release of endorphins, often referred to as ‘feel-good’ hormones. Physical activity can also lead to improved sleep patterns, greater energy levels, and enhanced cognitive function, which is increasingly important in the fast-paced modern world.

Incorporating just 30 minutes of exercise into your daily routine can be the catalyst for these health benefits. This could be as simple as a brisk walk, a cycle to work, or a morning swim. Making it a consistent part of your daily life can help establish a routine, making it more likely to stick as a habit. For those with busy schedules, breaking down the activity into shorter, 10-minute sessions can also be effective as well as being more manageable.

England’s National Health Service (NHS) provides resources and programs like ‘Couch to 5K’ to help people become more active. There is a strong emphasis on inclusivity, with guidance catering to all ages, abilities, and backgrounds, recognising that everyone stands to gain from the adoption of a more active lifestyle no matter what their age or individual characteristics.

Overall, the message from healthcare and public health professionals in the UK is clear: regular physical activity is essential for maintaining and improving health. As a professor of Primary Care and Public Health, I understand the importance of disseminating this message and empowering individuals to take control of their health through informed choices about physical activity. By making exercise a regular part of our daily lives, we can enhance our health, mood, and overall quality of life.

Making Sense of Sensitivity, Specificity and Predictive Value: A Guide for Patients, Clinicians and Policymakers

In this post, I will discuss sensitivity, specificity and positive predictive value in relation to diagnostic and screening tests. Many more people have become aware of these measures during the Covid-19 pandemic with the increased use of lateral flow and PCR tests.

In clinical practice and public health, sensitivity, specificity, and predictive value are important measures of the performance of diagnostic and screening tests. These measures can help clinicians, public health specialists and the public to understand the accuracy of a test and to make informed decisions about its use in patient care.

Sensitivity: The proportion of people with a disease who test positive on a diagnostic or screening test.

Sensitivity = True Positives / (True Positives + False Negatives)

Specificity: The proportion of people without a disease who test negative on a diagnostic or screening test.

Specificity = True Negatives / (True Negatives + False Positives)

Positive predictive value (PPV): The proportion of people who test positive on a diagnostic test who actually have the disease.

Positive Predictive Value = True Positives / (True Positives + False Positives)

Negative predictive value (NPV): The proportion of people who test negative on a diagnostic test who actually do not have the disease.

Negative Predictive Value = True Negatives / (True Negatives + False Negatives)

How do we Interpret sensitivity, specificity, and predictive value?

Sensitivity and specificity are linked measures. A test with high sensitivity is good at identifying people with a disease, but it may also produce false positives in people who do not have the disease. A test with high specificity is good at identifying people who do not have a disease, but it may also produce false negatives in people who do have the disease. In general, as sensitivity increases, specificity decreases; and vice versa.

Positive Predictive Value (PPV) depends on the prevalence of the disease in the population being tested. In a population with a high prevalence of disease, a positive test result is more likely to be a true positive. Conversely, in a population with a low prevalence of disease, a positive test result is more likely to be a false positive.

In clinical and public health practice this means that a test can have a high sensitivity and specificity but if it is being carried out in a population with a low prevalence, most positive tests are false positives; thereby limiting the value of a positive test. This is why a test can vary in its performance in primary care (where prevalence of a condition is often low) and in hospital care (where prevalence will generally be higher).

The Covid-19 pandemic brought global attention to the importance of diagnostic test parameters such as sensitivity, specificity and positive predictive value. Initial Covid-19 tests often prioritised sensitivity to capture as many positive cases as possible. However, as the pandemic progressed, the need for more specific tests became clear to minimise false positives that could distort public health strategies. For example, a false positive test could result in a person isolating or staying off work or school unnecessarily.

A test with a high Negative Predictive Value means that it is good at ruling out disease in people who test negative. This is important for public health interventions, such as contact tracing, where it is important to identify people who are unlikely to be infected with a disease so that they can be excluded from further monitoring and isolation.

The pandemic underscored that no single measure—sensitivity, specificity, or predictive value—could offer a complete picture of a test’s effectiveness.

Example of a diagnostic test: A Covid-19 test has a sensitivity of 90%, meaning that 90% of people with a Covid-19 infection will test positive on the test. The test has a specificity of 98%, meaning that 98% of people without Covid-19 will test negative on the test.

The PPV of the test will vary depending on the prevalence of Covid-19 in the population being tested. For example, if 5% of people in a population have Covid-19, then the PPV of the test will be 70%. This means that 70% of people who test positive on the test will actually have Covid-19.

If the prevalence of Covid-19 is 1%, then the PPV will be 31%. This means that 31% of people who test positive on the test will actually have Covid-19. Hence, at times of low prevalence, many positive Covid-19 tests will be wrong.

You can use a Positive Predictive Value Calculator to see how changing sensitivity, specificity and prevalence alters the result.

Screening tests have also become more important as health systems across the world try to detect conditions such as cancer earlier in their clinical course in an attempt to improve health outcomes survival.

Example of a screening test: A mammogram is a screening test for breast cancer. It has a sensitivity of 85%, meaning that 85% of women with breast cancer will have a positive mammogram. The mammogram has a specificity of 90%, meaning that 90% of women without breast cancer will have a negative mammogram. The PPV of the mammogram will vary depending on the prevalence of breast cancer in the population being screened. For example, if the prevalence of breast cancer in a population is 1%, then the PPV of the mammogram will be 8%. This means that 8% of women who have a positive mammogram will actually have breast cancer. Hence, many women who don’t have breast cancer will need investigation to confirm the result of their screening test.

Conclusion: Sensitivity, specificity, and predictive value are important concepts in the evaluation of diagnostic and screening tests. Clinicians, public health specialists and the public should understand the performance of a test before using it in patient care.

In addition to sensitivity, specificity, and predictive value, there are other factors that clinicians should consider when choosing a diagnostic or screening test, such as the cost of the test, the risks and benefits of the test, and the availability of alternative tests.

No diagnostic or screening test is perfect. All tests have the potential to produce false positives and false negatives. Clinicians, the public and policy-makers should use judgment to interpret the results of any test; and to make decisions about patient care, screening programmes and public health policy.

The Impact of Shielding and Loneliness on Physical Activity During the COVID-19 Pandemic

The COVID-19 pandemic had profound effects on many aspects of life, from healthcare to lifestyle habits. One of the most impacts has been the mental and physical well-being of individuals, particularly those who are older. Our study published in PLoS One aimed to quantify the relationship between shielding status and loneliness at the start of the pandemic and how these factors affected physical activity (PA) levels throughout the period. Conducted in London, the study surveyed 7748 cognitively healthy adults aged 50 and above from April 2020 to March 2021.


The study used the International Physical Activity Questionnaire (IPAQ) short-form to assess the physical activity levels of participants before the pandemic and six more times over the next 11 months. Linear mixed models were used to explore the relationship between shielding status and loneliness at the onset of the pandemic with physical activity over time.

Key Findings

Loneliness and Physical Activity

The study revealed that participants who felt ‘often lonely’ at the beginning of the pandemic completed significantly fewer Metabolic Equivalent of Task (MET) minutes per week during the pandemic. Specifically, they completed an average of 522 to 547 fewer MET minutes per week compared to those who felt ‘never lonely.’

Shielding and Physical Activity

Those who were advised to shield or self-isolate at the beginning of the pandemic also showed reduced levels of physical activity. They completed an average of 352 fewer MET minutes per week compared to those who were not shielding. After adjusting for demographic factors, the decrease was 228 fewer MET minutes per week.

Additional Factors

No significant associations were found between shielding, loneliness, and physical activity after further adjustments for health and lifestyle factors. This suggests that co-morbidities and health status also play an influential role.

Conclusions and Implications

The study indicates that those who were shielding or felt lonely at the start of the pandemic were likely to have lower levels of physical activity during the pandemic. Co-morbidities and health status also significantly influence these associations. Given the profound impact of physical activity on overall health, targeted interventions may be necessary to support these vulnerable populations in maintaining an active lifestyle, especially during challenging times like a pandemic.

For healthcare providers, public health professionals, and policy-makers, these findings underscore the need for comprehensive approaches that address not just the physical but also the psychological and social aspects of well-being, particularly for older adults. By understanding the interplay between these factors, we can aim for more effective public health strategies that promote a holistic approach to health and well-being, especially in times of crisis.

Decoding Risk in Clinical & Public Health Practice: Absolute vs Relative Risk Reduction

What is the difference between Absolute Risk Reduction (ARR) and Relative Risk Reduction (RRR)? This is a common question from students and clinicians. Understanding these concepts is crucial for interpreting research findings, especially in clinical and public health settings.

Absolute Risk Reduction (ARR) refers to the difference in outcomes between a control group and a treated group in a clinical trial or an public health study.

Formula: ARR = CER – EER

Where: CER is the Control Event Rate (rate of event in the control group) and EER is the Experimental Event Rate (rate of event in the experimental group).

Example: Imagine a trial in which 10% of patients in the control group have an adverse event, and only 5% in the treatment group experience the same.

ARR = 10% – 5% = 5%

This means that the drug reduces the absolute risk of an adverse event by 5%. In total, 20 people need to be treated to prevent one event (the Number Needed to Treat, NNT).

Relative Risk Reduction (RRR) is the proportional reduction in outcomes between the treated and untreated groups. It’s a way to contextualize the effectiveness of a treatment by considering the baseline risk.

Formula: RRR = {(CER – EER)}{CER} \times 100

Example: Continuing with the same drug trial, RRR = {(10% – 5%)}{10%} \times 100 = 50%

Interpretation: The drug reduces the relative risk of an adverse event by 50% compared to the control group.

Key Differences between ARR and RRR

  1. Context: ARR gives you the actual change in risk, which is straightforward and easily interpretable. RRR puts this change in the context of the baseline risk, making the treatment appear seem more effective than it may actually be.
  2. Impact: ARR is more useful for understanding the individual benefit of an intervention, while RRR is often more impressive for public health interventions where a small absolute change can have a large impact when scaled up.
  3. Communication: RRR is often used in marketing or in media because it tends to produce a larger, more eye-catching number. However, this can be misleading if not used with the ARR, which provides a more direct measure of an intervention’s effect.
  4. Clinical Relevance: Knowing both ARR and RRR can aid in shared decision-making between clinicians and patients. While RRR can show the effectiveness of a treatment, ARR can guide on how much benefit an individual patient can expect.

By understanding both Absolute Risk Reduction and Relative Risk Reduction, clinicians and public health specialists can better interpret the data from clinical, public and epidemiological studies, and subsequently make more informed decisions about treatment options and public health interventions.

Addressing the health needs of refugees and asylum seekers

The health risks to refugees and asylum seekers has become very topical with the identification of Legionella on the Bibby Stockholm barge Refugees and asylum seekers will often come from countries that have high rates of infections such as tuberculosis and hepatitis B / C (among others).

Refugees and asylum seekers will also often not be vaccinated to UK standards. A comprehensive health screen is essential when they enter the UK to identify and treat any infections they might have (as well as other significant medical problems such as diabetes and mental health issues).

It’s also essential to offer any missing vaccines to bring them in line with UK vaccination standards; and address any physical and mental health problems they have; and ensure they have access to good NHS primary care services to deal with new and ongoing medical problems.

Legionella is sometimes found in the water systems of larger buildings, particularly those with older systems where water can pool at the temperature at which Legionella can multiply quickly. Suitable action to deal with the water system is needed when Legionella is identified to reduce the risk of Legionnaire’s disease to people using and living in the affected building.

The poorer the quality & maintenance of the water system, the more likely Legionella will be found and the more difficult it will be to control. Older people, those with chronic lung disease or other serious medical problems such as diabetes, and weak immune systems are at highest risk of serious illness from Legionella.

The accommodation for refugees and asylum seekers can be environments where infections spread rapidly, because these sites are often crowded and the people living in them will often congregate together. This poses a threat to both the health of the residents and the wider community because infectious and parasitic diseases such as Covid-19, gastroenteritis and scabies can then spread quickly among the residents. Appropriate surveillance, medical care and public health interventions are crucial to mitigate these risks.

The Increasing Impact of Heatwaves: A Global Health Challenge

The harsh reality of climate change is becoming increasingly apparent, with extreme temperatures emerging as an increasing global phenomenon. One of the most conspicuous manifestations of this climatic shift is the occurrence of heatwaves. These bouts of extreme heat aren’t just uncomfortable, they also pose significant health risks and can increase death rates; particularly amongst the most vulnerable people in societies – such as the elderly, children, and individuals with pre-existing health conditions.

Heatwaves don’t just affect the health of individuals; they also put enormous strain on healthcare systems. In times of extreme temperatures, the influx of patients seeking medical help for heat-related illnesses increases drastically. Often, other factors linked with extreme heat, like water shortages and poor air quality, exacerbate the situation, leading to an even greater health crisis.

The ability to effectively manage these health threats often comes down to the resources and infrastructure a country has in place. Countries with advanced infrastructures are typically better equipped to handle these challenges. They can provide the necessary healthcare, deploy strategies to keep the population cool, and improve the urban infrastructure to mitigate the impact of high temperatures. .

However, for lower-income countries, the picture isn’t as bright. In such countries, which regularly experiences high temperatures and have less developed infrastructure, the challenge is significantly more daunting. It’s much more difficult for these nations to provide the level of healthcare required during a heatwave or to put strategies in place to protect the population from the extreme heat.

This makes it even more imperative for such regions to establish robust measures to mitigate the health impacts of climate change and extreme heat. The strategies needed are wide-ranging – from improving their healthcare systems and response to heat-related illnesses, to launching comprehensive climate adaptation and mitigation policies. These actions are not just necessary, they are urgent, because when it comes to heatwaves and the health threats they bring, we are all feeling the impact.

Group A streptococcal infections in the UK

There is currently considerable media coverage and some public anxiety in the UK about Group A streptococcal (GAS) infections. Journalists who write about cases of infectious diseases need to understand the principles of the Poisson distribution. Events such as infections can sometimes cluster in time or space due to chance, and not because there is an underlying cause behind the cluster of cases.

Some journalists and doctors are stating that the cases of Group A streptococcal infections we are currently seeing in the UK are from lower levels of immunity because of Covid-19 control measures over the last 2.5 years. This is not necessarily the case and needs further investigation. The UK has experienced large outbreaks of Group A streptococcal infections in the past. For example, the UK had a large outbreak of Group A streptococcal infections between September 2015 and April 2016 (the largest since 1969), resulting in PHE issuing an alert.

The current cluster of Group A streptococcal infections won’t be the last we will see in the UK. Outbreaks of this and other infections will continue to occur. What is important is that our public health agencies and the NHS have the capacity to investigate and manage any outbreaks.

Lifting of Covid-19 restrictions in England – What are the implications for public health?

Why are all restrictions being lifted even though Covid cases are rising?

The number of cases of Covid-19 has been increasing since May and there are now nearly 30,000 cases each day in the UK. In the past, such a high number of cases would have led to a large number of people admitted to hospital and also an increase in deaths. Fortunately, because of vaccination, the number of people with a severe Covid-19 illness is now much lower than previously. For example, in the last week, there have been around 20 deaths per day on average from Covid-19 across the UK. This compares to more than 1,000 deaths per day during some days in January. The number of hospital admission is also low, with around 300 hospital admission each day in the UK. The government believes that vaccination is breaking the link between the number of cases and the number of people with severe illness; and it therefore safe to end Covid-19 restrictions in England on 19 July. The government accepts that the number of Covid-19 cases will remain at a high level.

Will the 1m social distancing rule be scrapped everywhere?

The 1m social distancing rule will end in England on 19 July, meaning that people can mingle indoors and outdoors in larger groups. Indoor businesses like night clubs will also be allowed to open.

Will we still be advised to wear masks even though it’s no longer a rule, and why?

The government has said that wearing masks will be a personal choice, except in a few higher risk settings such as care homes. Many scientists, doctors and public health specialists disagree with this decision and would like to have seen mask wearing remaining compulsory until the number of Covid-19 cases was at a much lower level than it is now.

Should I keep wearing a mask in public transport?

My advice would be to continue to wear a mask on public transport after 19 July as this protects others from the risk of infection. However, this will be optional once Covid-19 regulations end in England. It is possible though that some airlines will continue to make mask use mandatory on their flights.

What’s the risks of maskless shopping?

The risk of acquiring an Covid-19 infection is much higher in crowded, poorly-ventilated indoor settings. Once the 1m rule is scrapped, shops will be much more crowded than they are now, which will make them a higher-risk setting for transmission of infection. If you are in a vulnerable group – such as the elderly or with a serious medical problem – you may wish to consider wearing a more protective FFP2 mask when you are shopping or in other crowded, indoor spaces.

And of singing in church?

A number of large Covid-19 outbreaks have been linked to places of worship. When people sing, they expel more air and make transmission of infection more likely in crowded, indoor settings, such as churches. Because churchgoers are often elderly, churches may wish to retain some social distancing measures after 19 July to protect the members of their congregation.

If my employer wants me to go back to the office but I don’t feel safe, can I refuse?

Employees with at least 26 weeks of service have the right to ask for flexible working, which can include working from home. Employers must consider the request but can decline it if there are good business or operational reasons for doing so. If you do have to work in the office, your employer should carry out a risk assessment to ensure your working environment is safe for you.

What might happen in schools if measures are scrapped but children aren’t vaccinated?

In recent weeks, many schools have experienced Covid-19 outbreaks, with around 640,000 children across England currently at home because there has been a case in their bubble. As most schools will close around 19 July for the summer holiday, there won’t be an immediate effect on schools. However, when schools re-open in September, there will be a risk that we will see further outbreaks in schools because children have not been vaccinated. We should be looking at implementing other mitigation measures to reduce the risk of infection in schools, such as ventilation and air cleaning systems, as has been done in countries such as the USA.

I’ve had both vaccines – can I still catch it, and how bad could it be?

The vaccines used in the UK provide good protection against symptomatic infection (around 80% after two doses) and even better protection (over 90%) against hospital admission and death. However, some people who are fully immunised can still get infected and a small proportion of these people will develop a severe illness that could result in hospital admission or death as no vaccine is 100% effective.

I haven’t had the vaccine – what precautions should I take?

You should continue to follow government regulations on social distancing and wearing face masks until 19 July. After then, you need to bear in mind that Covid-19 infections remain at a high level and so you should continue to be cautious in crowded, poorly-ventilated indoor spaces; particularly if you are from a more vulnerable group at higher risk of a serious illness if you become infected.

Is there a risk scrapping Covid measures could send us back into lockdown?

It’s likely that Covid-19 cases will remain at a high level during the summer because of the ending of Covid-19 rules and greater mixing of people in indoor settings. However, vaccination should keep deaths and, to a lesser extent, hospital admissions at a low enough level to avoid another lockdown. There is though always a risk that even more infectious variants of the coronavirus may emerge that will make current vaccines less effective and precipitate another lockdown.

What about vaccination?

Currently, around 86% of adults in the UK have had one dose of vaccine and 64% have had two doses. As two doses of vaccine are needed to provide effective protection, this means there are still many people who are at risk. Do attend for your first vaccination if you have not already done so and attend for your second vaccination when this is due. Many areas are offering walk-in vaccination clinics, which you can attend without an appointment.

How risky are pubs now people can order and drink at the bar?

Crowded, poorly ventilated locations such as pubs will be high risk settings for transmission of Covid-19 once restrictions end on 19 July. Because people in pubs will be drinking and lose some of their social inhibitions, and also speaking loudly, this adds to the infection risk.

When and how should we relax Covid-19 lockdown restrictions in the UK?

There is increasing discussion about how and when we should relax Covid-19 lockdown restrictions in the UK. My view is that we should be guided by data on case numbers, hospitalisations and deaths; and lift restrictions cautiously. In recent weeks, we have seen positive progress on case numbers with the daily number of people with positive Covid-10 tests falling from a peak over 50,000 per day earlier in the year to under 15,000 per day more recently. Hospitalisations and deaths are also falling but will lag behind the decrease in case numbers.

There are reasons to be positive about the future. Vaccination numbers are increasing daily with over 15M people now vaccinated against Covid-19, and administration of second vaccine doses due to start soon, as well as extension of vaccination to younger age groups. We are on target to offer a Covid-19 vaccine to all adults by later in 2021. However, we have seen lower vaccination rates in some groups, such as people from ethnic minorities, and it is essential to work with communities to overcome this vaccine hesitancy.

Another reason for optimism is that a large number of people also have some natural immunity to Covid-19 because of previous infection. Last year’s experience also shows that there is a seasonal effect on case numbers. Hence, we can be optimistic about seeing a decline in Covid-19 case numbers in the summer. We need though to avoid lifting restrictions too quickly and should do so in a gradual manner starting with opening up schools, and then opening up other sectors of the economy and society to avoid an increase in cases, hospitalisations and deaths in the Spring.

Finally, we need to be fully prepared for a potential increase in Covid-19 cases in the Autumn and Winter. This means ensuring that a high proportion of adults have had two doses of vaccine, and that we have a fully functional test and trace system in place by then. We are also likely to need continuing restrictions on overseas travel and travel to the UK; as well as planning for “booster” doses of vaccines to protect against newer and more infectious strains of SARS-CoV-2.