Author: Azeem Majeed

I am Professor of Primary Care and Public Health, and Head of the Department of Primary Care & Public Health at Imperial College London. I am also involved in postgraduate education and training in both general practice and public health, and I am the Course Director of the Imperial College Master of Public Health (MPH) programme.

Understanding Allergy – by Dr Sophie Farooque

In this concise guide, Dr Sophie Farooque – a Consultant in Allergy at St. Mary’s Hospital in London and one of the UK’s leading experts on the treatment of allergic disorders – gives an excellent overview of allergies that will be a very useful guide for the public and also for health professionals.

Allergic disorders have increased substantially in prevalence in recent decades. This is shown in our personal experience as well as by research on the epidemiology of allergic disorders. When I was in school, problems such as hay fever and food allergy were all uncommon in my classmates. This in contrast to now, when many families will have a member who suffers from an allergic disorder. In milder cases, these disorders can be irritating and reduce people’s quality of life. But in more severe cases, they can lead to hospitalisation and sometimes even to death.

Hence, some knowledge of allergies and how they can be managed is very helpful to families who have a member who suffers from an allergy; and can improve their quality of life, as well as allowing them to make better use of NHS services for allergy, whether these are received from general practices or specialist allergy clinics. It is a sad fact that the provision of specialist allergy services by the NHS is well below the need for them, leading to many families and allergy sufferers relying on self-management or on advice from their general practitioners.

In her book, Dr Sophie Farooque covers the most common allergic disorders – such as allergic rhinitis, food allergy, and drug allergies; as well as anaphylaxis, a potentially life-threatening condition. She also discusses “red herrings”; problems that people think are due to an allergy but which in fact have another cause. She also gives very useful advice on self-management and on when medication would be beneficial.

A better understanding of allergies and their treatment is essential for many people and I highly recommend this very readable book for anyone who wants to learn more about the topic and manage their allergies better or improve the treatment of allergies in their children.

Understanding Allergy is published as part of the Penguin Life Experts series and is available from Amazon and other book sellers.

Ethnic disparities in the uptake of colorectal cancer screening

Colorectal cancer is one of the most common cancers and most common cause of cancer deaths worldwide. Despite the availability of screening, disparities in survival from colorectal continue in certain ethnic minority groups. This may, in part, be secondary to low take-up of bowel cancer screening. Different ethnic groups may have different cultural and health beliefs, different levels of education, understanding and acculturation that negatively impacts upon their use of faecal testing and endoscopic procedures.

In a systematic review published in the journal Perspectives in Public Health, we examined studies that had investigated ethnic differences in the uptake of colorectal cancer screening.

We found that disparities in colorectal cancer screening are multifactorial and complex in their origin and that ethnicity plays an important role. Although seemingly intuitive, this is the first systematic review that summarises the association between uptake of screening in specific ethnic groups and which highlights the presence of significant variations in ethnicity classification globally.

Further consistent international research is required to understand why specific ethnic groups are less likely to take up colorectal cancer screening to help in the development of more tailored public health messaging to improve screening rates and to reduce disparities in health outcomes.


Clinical vignettes in benchmarking the performance of online symptom checkers

In the USA, over one-third of adults self-diagnose their conditions using the internet, including queries about urgent (ie, chest pain) and non-urgent (ie, headache) symptoms. The main issue with self-diagnosing using websites such as Google and Yahoo is that user may get confusing or inaccurate information, and in the case of urgent symptoms, the user may not be aware of the need to seek emergency care. In recent years, various online symptom checkers (OSCs) based on algorithms or artificial intelligence (AI) have emerged to fill this gap

Online symptom checkers are calculators that ask users to input details about their symptoms of sickness, along with personal information such as gender and age. Using algorithms or AI, the symptom checkers propose a range of conditions that fit the symptoms the user experiences. Developers promote these digital tools as a way of saving time for patients, reducing anxiety and giving patients the opportunity to take control of their own health.

The diagnostic function of online symptom checkers is aimed at educating users on the range of possible conditions that may fit their symptoms. Further to presenting a condition outcome and giving the users a triage recommendation that prioritises their health needs, the triage function of online symptom checkers guides users on whether they should self-care for the condition they are describing or whether they should seek professional healthcare support.3 This added functionality could vastly enhance the usefulness of Online symptom checkers by alerting people about when they need to seek emergency support or seek non-emergency care for common or self-limiting conditions.

In a study published in the journal BMJ Open, we assessed the suitability of vignettes in benchmarking the performance of online symptom checkers. Our approach included providing the vignettes to an independent panel of single-blinded physicians to arrive at an alternative set of diagnostic and triage solutions. The secondary aim was to benchmark the safety of a popular online symptom checkers (Healthily) by measuring the extent that it provided the correct diagnosis and triage solutions to a standardised set of vignettes as defined by a panel of physicians.

We found significant variability of medical opinion depending on which group of GPs considered the vignette script, whereas consolidating the output of two independent GP roundtables (one from RCGP and another panel of panel of independent GPs) resulted in a more refined third iteration (the consolidated standard) which more accurately included the ‘correct’ diagnostic and triage solutions conferred by the vignette script. This was demonstrated by the significant extent that the performance of online symptom checkers improved when benchmarked between the original and final consolidated standards.

The different qualities of the diagnostic and triage solutions between iterative standards suggest that vignettes are not an ideal tool for benchmarking the accuracy of online symptom checkers, since performance will always be related to the nature and order of the diagnostic and triage solutions which we have shown can differ significantly depending on the approach and levels of input from independent physicians. By extension, it is reasonable to propose that any consolidated standard for any vignette can always be improved by including a wider range of medical opinion until saturation is reached and a final consensus emerges.

The inherent limitations of clinical vignettes render them largely unsuitable for benchmarking the performance of popular online symptom checkers because the diagnosis and triage solutions assigned to each vignette script are amenable to change pending the deliberations of an independent panel of physicians. Although online symptom checkers are already working at a safe level of probable risk, further work is recommended to cross-validate the performance of online symptom checkers against real-world test case scenarios using real patient stories and interactions with GPs as opposed to using artificial vignettes only which will always be the single most important limitation to any cross-validation study.

A Clinician-Assisted Digital Cognitive Behavioural Therapy Intervention for Smoking Cessation

In a study published in the journal Nicotine and Tobacco Research, we evaluated the secondary effectiveness outcomes for Quit Genius, a digital clinician-assisted cognitive behavioural therapy (CBT) intervention for smoking cessation.

Adult smokers (N=556) were randomly assigned to Quit Genius (n=277), a digital, clinician-assisted CBT intervention or Very Brief Advice (VBA) to stop smoking, an evidence-based, 30-second intervention designed to facilitate quit attempts, coupled with referral to a cessation service (n=279). Participants were offered combination nicotine replacement therapy (patches and gum) tailored to individual nicotine dependence. Analyses (N=530), by intention-to-treat, compared Quit Genius and VBA at 4, 26, and 52 weeks post-quit date.

The primary outcome was self-reported seven-day point prevalence abstinence at 4 weeks post-quit date. Consecutive seven-day point-prevalence abstinence, defined as abstinent at two or more consecutive timepoints, was examined at weeks 26 and 52 to indicate long-term effectiveness. Abstinence was verified using a random sample of participants with carbon monoxide breath testing of <5 parts per million (n=280).

Self-reported consecutive seven-day point prevalence abstinence at weeks 26 and 52 for Quit Genius was 27.2% and 22.6% respectively, compared to VBA which was 16.6% and 13.2% (RR=1.70,95% CI,1.22-2.37;p=0.003, 26 weeks; RR=1.71,95% CI,1.17-2.50; p=0.005, 52 weeks). Biochemically verified abstinence was significantly different at 26- (p=0.03) but not 52 weeks (p=0.16). Quit Genius participants were more likely to remain abstinent than those who received VBA (RR=1.71,95% CI 1.17-2.50;p=0.005).

This study provides secondary evidence for the long-term effectiveness of Quit Genius in comparison with VBA. Future trials of digital interventions without clinician support and comparisons with active treatment are needed.

The long-term effectiveness of clinician-assisted digital smoking cessation interventions has not been well-studied. This study established the long-term effectiveness of an extended CBT-based intervention; results may inform implementation of scalable approaches to smoking cessation in the health system.


Do callers follow the advice given by NHS 111?

The National Health Service (NHS) 111 helpline was set up to improve access to urgent care in England, efficiency and cost-effectiveness of first-contact health services. Following trusted, authoritative advice is crucial for improved clinical outcomes. In paper published in the journal PLOS ONE, we examined patient and call-related characteristics associated with compliance with advice given in NHS 111 calls.

The importance of health interactions that are not face-to-face has recently been highlighted by COVID-19 pandemic. In this retrospective cohort study, NHS 111 call records were linked to urgent and emergency care services data. We analysed data of 3,864,362 calls made between October 2013 and September 2017 relating to 1,964,726 callers across London. A multiple logistic regression was used to investigate associations between compliance with advice given and patient and call characteristics.

Caller’s action is ‘compliant with advice given if first subsequent service interaction following contact with NHS 111 is consistent with advice given. We found that most calls were made by women (58%), adults aged 30–59 years (33%) and people in the white ethnic category (36%). The most common advice was for caller to contact their General Practitioner (GP) or other local services (18.2%) with varying times scales. Overall, callers followed advice given in 49% of calls.

Compliance with triage advice was more likely in calls for children aged <16 years, women, those from Asian/Asian British ethnicity, and calls made out of hours. The highest compliance was among callers advised to self-care without the need to contact any other healthcare service.

This is one of the largest studies to describe pathway adherence following telephone advice and associated clinical and demographic features. These results could inform attempts to improve caller compliance with advice given by NHS 111, and as the NHS moves to more hybrid way of working, the lessons from this study are key to the development of remote healthcare services going forward.


Defining the determinants of vaccine uptake and under-vaccination in migrant populations in Europe

Our new article in Lancet Infectious Diseases discusses why some migrants in Europe are at risk of under-immunisation and show lower vaccination uptake for routine and COVID-19 vaccines. Addressing this issue is critical if we are to address vaccination inequities and meet the goals of WHO’s new Immunisation Agenda 2030.

We carried out a systematic review exploring barriers and facilitators of vaccine uptake (categorised using the 5As taxonomy: access, awareness, affordability, acceptance, activation) and sociodemographic determinants of under-vaccination among migrants in the EU and European Economic Area, the UK, and Switzerland.

We identified multiple access barriers—including language, literacy, and communication barriers, practical and legal barriers to accessing and delivering vaccination services, and service barriers such as lack of specific guidelines and knowledge of health-care professionals—for key vaccines including measles-mumps-rubella, diphtheria-pertussis-tetanus, human papillomavirus, influenza, polio, and COVID-19 vaccines.

Acceptance barriers were mostly reported in eastern European and Muslim migrants for human papillomavirus, measles, and influenza vaccines. We identified 23 significant determinants of under-vaccination in migrants, including African origin, recent migration, and being a refugee or asylum seeker.

We did not identify a strong overall association with gender or age. Tailored vaccination messaging, community outreach, and behavioural nudges facilitated uptake. Migrants’ barriers to accessing health care are already well documented, and this Review confirms their role in limiting vaccine uptake.

These findings hold immediate relevance to strengthening vaccination programmes in high-income countries, including for COVID-19, and suggest that tailored, culturally sensitive, and evidence-informed strategies, unambiguous public health messaging, and health system strengthening are needed to address access and acceptance barriers to vaccination in migrants and create opportunities and pathways for offering catch-up vaccinations to migrants.


Depression and unplanned secondary healthcare use in people with multimorbidity

Multimorbidity, the co-occurrence of two or more chronic conditions, is increasing in prevalence and affecting approximately a third of all adults globally. In the UK, the prevalence of individuals with four or more long-term conditions is projected to increase to 17% by 2035, compared to 9.8% in 2015. Approximately two thirds of this population will have a mental illness such as depression , which is in turn strongly associated with the incidence of a multitude of long-term conditions.

As the number of physical conditions a person increases, the odds of having a mental health disorder increase by almost double for one condition, and six times for more than five conditions. The presence of a mental health comorbidity such as depression is associated with poorer clinical outcomes and quality of life, compared to individuals with physical conditions only.

In an article published in the journal PLOS ONE, we summarised the current evidence on the association between depression and unplanned secondary healthcare use among patients with multimorbidity. To our knowledge, the literature is limited on specifically depression-related multimorbidity clusters, namely different combinations of comorbidities, or specific patient characteristics and the subsequent effect on unplanned secondary healthcare use. Therefore, this review also aimed to explore the effect of the types of comorbidities and if available, different clusters of comorbidities, and sociodemographic predictors of unplanned secondary healthcare among patients with both multimorbidity and depression.

We found that presence of depression increases the likelihood of emergency hospital admissions and readmissions in patients with multimorbidity. This association holds across a range of long-term conditions characterising multimorbidity in various countries, settings and samples. Depression also predicted increased emergency department visits in most of the studies reporting on this outcome. Moreover, the greater the severity of depression, the greater the risk of emergency hospital admissions and emergency department visits.

Patients with co-occurring depression with cancer, COPD, and asthma showed some of the greatest magnitudes of risk of unplanned secondary healthcare use. Being female, of older age and having a greater number of long-term conditions were other predictors of unplanned secondary healthcare use.


Data from the NHS is playing a key role in guiding vaccination policies globally

Throughout the pandemic, the UK’s covid-19 data systems have been guiding global as well as local policies. The well-established health information systems combined with the more recently established National Immunisation Management System in England provided timely information on infections, emergence of new variants, and the value of different interventions. But one of the most important contributions from the UK came from the ability to rapidly track vaccine effectiveness.

Vaccination is the best method for societies to reduce the severity of illness and number of deaths from covid-19; and to start to return to a more normal way of living, working, and studying.[1] But vaccination programmes need to be evidence-based, so that vaccines and healthcare resources are used appropriately, and there is equitable vaccine delivery. The covid-19 pandemic has shown the importance of data from medical records and the National Immunisation Management System in guiding national vaccination policies. Clinical trials can provide initial data on the efficacy and safety of vaccines. However, because of their relatively small size and short duration of follow-up, they cannot provide longer-term data on vaccine effectiveness or on rare adverse events.[2] Furthermore, because covid-19 vaccines were designed to target the original strain of SARS-CoV-2, the trials are also unable to provide data on protection against new variants that emerged after the trials were completed. Nor were they able to provide data on the need for booster doses of vaccines to maintain protection from serious illness and death.

Clinical trials are also generally unable to provide data on smaller subgroups of the population such as people who are immunocompromised; or how different vaccines compare in their long-term safety and effectiveness. This data has to largely come from national immunisation systems and from medical records, as does data on vaccine uptake in different groups of the population. These are areas where the UK has excelled during the covid-19 pandemic in work led by government organisations such as the UK Health Security Agency and the UK Office for National Statistics.

In England, the UK Health Security Agency has assessed vaccine effectiveness against symptomatic covid-19 infection using community testing data linked to vaccination data from the National Immunisation Management System (NIMS); with further linkage to data from electronic NHS secondary care datasets;  sequencing and genomics data; travel information; and mortality records. These data have allowed analysis of how well covid-19 vaccines protect against outcomes such as hospitalisation and death as well as against symptomatic infection during the course of the pandemic.[3] With the linkage of secondary care datasets and NIMS data, it has also allowed for timely epidemiological safety signal assessments to be rapidly carried out in response to passive reports of adverse events after vaccination from the MHRA yellow card system. The large size of the English population allows for more precise estimation of these effects; something that is not always possible in data from countries with smaller health systems. Data from the UK also allowed identification of people at highest risk from the complications of covid-19, which helped in deciding which groups would be prioritised for vaccination. UK data also allowed the tracking of breakthrough infections following vaccination better than any other country; and confirmed that delaying the second dose of vaccine was likely to lead to better protection from serious illness.

Most recently, the data has allowed analysis of how well vaccines protect against new variants of SARS-CoV-2 such delta and omicron. The latest data confirm that three doses of vaccines provide good protection from hospitalisation and death from an omicron infection; but that the level of protection is not as high as against the delta variant that was previously predominant in many parts of the world. [4] Protection against infection is also less against newer variants than against the original strain of SARS-CoV-2, which meant that breakthrough infections in vaccinated people were common, particularly at times when community infection rates are high.[4] The data also show that longer-term protection is better with the mRNA vaccines in use in the UK (Pfizer-BioNTech and Moderna) than with the AstraZeneca viral vector vaccine. Ongoing work will show how well this protection from serious illness and death is maintained; and whether further booster doses may be needed in the population more widely after the implementation of a fourth dose in older people and the clinically vulnerable.[5] In addition, epidemiological assessments of safety signals will continue to support and maintain confidence in the covid-19 vaccine programme.

Other data can be linked to the NIMS to allow estimation of vaccine uptake by age group, area of England and by ethnic group. This has proved essential in identifying population groups and geographical areas with lower than average vaccine uptake. For example, the data has shown that vaccine uptake is generally lower in younger age groups than among older people; and lower in large, urban areas such as London than in other parts of England.[6] The development of a public-facing “data dashboard” has allowed easy viewing of this data at national, local and regional level; thereby supporting public health teams to identify areas and communities with lower vaccine uptake.[7]

Looking forward, it is important that we maintain our data collection, linkage, analysis and publication abilities for the longer-term.[8] Although we must now all learn to live with covid-19, SARS-CoV-2 will still pose a threat to global health for some time, especially if new escape variants emerge.[9] Furthermore, with population-level immunity after vaccination waning and covid-19 control measures ending, there is a risk that later in the year we may see a surge in infections in the UK and elsewhere; in recent weeks, we have already seen an increase in covid-19 infections and hospital admissions in the UK. In addition, changes in testing behaviour and guidance may affect how vaccine effectiveness is monitored in the future. The data systems, scope for data linkage, and the analytical capacity in the UK will prove essential in tackling the long-term threat to global public health from covid-19; and lessons from the UK’s data systems should continue to be shared with the rest of the world to support the global response to covid-19.[10]

Azeem Majeed, Elise Tessier, Julia Stowe, Ali Mokdad

A version of this article was first published in the British Medical Journal.



  1. Majeed A, Molokhia M. Vaccinating the UK against covid-19. BMJ. 2020 Nov 30;371:m4654. doi: 10.1136/bmj.m4654.
  2. Majeed A, Papaluca M, Molokhia M. Assessing the long-term safety and efficacy of COVID-19 vaccines. Journal of the Royal Society of Medicine. 2021;114(7):337-340.
  3. Monitoring reports of the effectiveness of COVID-19 vaccination.
  4. Andrews N, Stowe J, Kirsebom F, et al. Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant. N Engl J Med. 2022 Mar 2. doi: 10.1056/NEJMoa2119451.
  5. Walker P, David N. UK: over-75s and vulnerable people to be offered additional Covid booster jab.
  6. Office for National Statistics. Coronavirus (COVID-19) latest insights: Vaccines.
  7. Official UK government website for data and insights on coronavirus (COVID-19).
  8. Tapper J. Dismay as funding for UK’s ‘world-beating’ Covid trackers is axed.
  9. Murray CH, Mokdad AH. After the Mandates End. Preparing for the next COVID-19 variant.
  10. Dowd JB. The UK’s covid-19 data collection has been “world beating”—let’s not throw it away. BMJ 2022; 376 :o496.

Testing NHS Staff for Covid-19

There was no mention from the Chancellor, Rishi Sunak, in his speech on Wednesday 23 March 2022 about the continued funding of Covid-19 testing for NHS staff in England. We need the government to clarify this urgently and confirm whether twice weekly testing of healthcare workers will continue or stop in April 2022.

Under current guidance, NHS staff are required to test for Covid-19 twice weekly and report their results before coming to work. If testing is to continue from April onwards, then the NHS will have to find this funding from its existing budgets, reducing funding for other areas of care.

There has been discussion about staff paying for their own testing. My view is that if testing is required by NHS employers, they will need to fund the tests. Staff cannot be asked to fund their own tests if this is a condition of their employment.

Ending regular Covid-19 testing of NHS will increase the risk of infection spreading to vulnerable patients. But there are also costs associated with testing and we need a robust assessment of the evidence on which to base future testing policy for NHS staff.

Protecting yourself from Covid-19

The recent increase in Covid-19 rates in the UK is concerning although, to some extent, an increase in rates was expected now that control measures have ended in England, with the other three UK countries also ending most control measures as well.

We are also seeing signs of increased NHS pressures with more presentations of people with suspected or confirmed Covid-19 in primary care and hospital admissions increasing. The number of NHS staff off work due to Covid-19 is also adding to NHS pressures.

A key message for the public is that vaccination is essential. Many people have not come forwards for a booster vaccine, particularly in London and other large cities. Three doses of vaccine are essential to reduce the risks of serious illness and death from Covid-19.

A second booster programme is also now starting for the most vulnerable people in our society: people aged 75 years and over this living in care home and people who are immunocompromised. The additional booster will provide these people with greater protection from serious illness and death.

I also advise people to continue to wear a mask (preferably a FFP2 mask) when in shops and on public transport. People should also continue to self-isolate if they test positive for Covid-19 to reduce the risks of infection to others.

Given that infection rates are increasing again, people who are clinically vulnerable through age or their medical history need to be cautious about entering places where there is a high-risk of infection (i.e. crowded, indoor venues with poor ventilation).

The government should also continue with PCR testing for people with symptoms of a possible Covid-19 infection and not scale back testing as it seems to be planning from April onwards. Unfortunately, there is no easy way out of the pandemic and testing along with good infection control measures remain essential.