Tag Archives: Peter Chilton

Vaccination Savings

We know that vaccination is one of the most cost-effective interventions in terms of improving public health, but it can only be at its most effective if it is encouraged and supported by policy-makers and government officials. A recent paper in the Bulletin of the World Health Organization looked at the potential economic benefits of providing ten different vaccinations in 73 low- and middle-income countries.[1] These included vaccinations against hepatitis B, measles, rubella, and yellow fever. The authors found that if vaccinations were given routinely between 2001 and 2020, not only would 20 million children avoid death, but there would also be an estimated saving of $347 billion. This figure is predominantly made up of lifelong productivity gains from deaths avoided ($330 billion), but also from disabilities avoided ($9.4 billion), treatment costs ($4.5 billion), transport costs ($0.5 billion), and lost caregiver wages ($0.9 billion). Further they estimate that $820 billion would be saved from the broader economic and social value of vaccinations. The biggest contributor to these estimates was vaccination against measles, followed by H. influenza type b, S. pneumoniae, and hepatitis B.

— Peter Chilton, Research Fellow


  1. Ozawa S, Clark S, Portnoy A, et al. Estimated economic impact of vaccinations in 73 low- and middle-income countries, 2001–2020. Bull World Health Organ. 2017

Researchers – Beware of Predators

A recent column in Nature draws attention to ‘predatory journals’ – journals that charge open access publication fees without editorial or publishing services (such as peer-review) that are usually seen with legitimate journals.[1] Anecdotally, researchers have found that, after submitting a manuscript, they are presented with a hitherto unmentioned charge for publishing, and then when refusing to pay find that the paper is still ‘published’, making it much more difficult for it to published in another, legitimate, journal. Further, they were then invoiced for a retraction fee to remove the paper. Others have found that they have been listed on a journal’s editorial board without their explicit consent.

Although many researchers may feel that they would not fall for a predatory journal, it is still possible, especially for those who are early career researchers, those who have had a string of rejections and are feeling pressurised to publish, or those who are distracted by other concerns. Fortunately Shamseer and colleagues conducted a cross-sectional comparison study of nearly 300 journals to discern if there were any characteristics more strongly associated with predatory journals.[2] They identified 13 such characteristics that are more likely to be seen:

  1. Including biomedical and non-biomedical subjects in their scope of interest, and in particular subjects with little overlap.
  2. Having spelling and grammar errors.
  3. Using unauthorised and/or low-resolution images.
  4. Using language on the website that targets authors as opposed to readers. For example, focusing on inviting submissions, promoting metrics, etc. as opposed to highlighting recent publications.
  5. Promoting the Index Copernicus Value as a metric.
  6. Lacking description of the manuscript handling process.
  7. Requesting that manuscripts are submitted through email, as opposed to through a submission system. This often ignores requirements such as conflicts of interest declarations, funding statements, etc.
  8. Promising rapid publication.
  9. Having no retraction policy.
  10. Having no detail on digital preservation.
  11. Having low publishing fee (e.g. <$150, as opposed to >$2000 in legitimate journals).
  12. If the journal claims to be open access, either retains copyright, or fails to mention it.
  13. Having a non-professional or non-journal affiliated email address as a point of contact.

Of course, having one or some of these characteristics does not mean the journal is predatory, but should indicate that you take a closer look.

— Peter Chilton, Research Fellow


  1. Cobey K. Illegitimate journals scam even senior scientists. Nature. 6 September 2017.
  2. Shamseer L, Moher D, Maduekwe O, et al. Potential predatory and legitimate biomedical journals: can you tell the difference? A cross-sectional comparison. BMC Medicine. 2017; 15: 28.

“A Canary in the Coal Mine for Male Health”

For the past two decades, at least, there have been concerns over declining sperm count. This is an important public health issue for a number of reasons. While low sperm count is only loosely correlated with male infertility, it has also been shown to be associated with all-cause mortality, morbidity, testicular cancer and various other disorders.

Levine and colleagues conducted a meta-analysis of 185 studies covering 38 years, which looked at the semen of 42,935 men in total.[1] Adjusted meta-regression analysis showed that the sperm concentration of semen had declined significantly between 1973 and 2011 (slope of -0.64, 95% CI -1.06 to -0.22, p=0.003). On average, the mean sperm concentration had declined by 0.75% per year, with an overall drop of 28.4% since 1973. Sub-group analysis found significant decline among both unselected men (who were not selected by whether they were fertile or not, such as in screening for military service) and fertile men (who were known to have conceived a pregnancy) from Western countries (North America, Europe, Australia and New Zealand). The drop was most pronounced in unselected Western men who had declined by 1.5% per year, with an overall drop of 52.4%.

The results for all men, as well as the sub-groups, were similar when the analysis was repeated using studies conducted post-1995, suggesting that the decline was not ‘levelling off’.

Numerous factors have been suggested for contributing to such a decline, with studies showing plausible associations between sperm count and environmental oestrogens, pesticides, heat, and lifestyle factors, such as diet, stress, smoking and BMI. The authors suggest that a declining sperm count may be “a canary in the coal mine” for male health – and there is a pressing need for further research into its causes.

085 DCv A Canary in the Coalmine for Male Health Figure 1

— Peter Chilton, Research Fellow


  1. Levine H, Jørgensen N, Martino-Andrade A, et al. Temporal trends in sperm count: a systematic review and meta-regression analysis. Hum Reprod Update. 2017; 1-14.

How Much Fruit and Veg is Enough?

We are often told that we should be eating five (or is it now ten?) portions of fruit and vegetables each day to protect against, amongst other things, cardiovascular disease (CVD).[1] However, such recommendations are generally based on research conducted in people from Europe, the USA, Japan and China. There is little data from countries in the Middle East, South America, Africa or South Asia.

The PURE study (Prospective Urban Rural Epidemiology) set out to rectify this, recruiting 135,000 participants from 18 countries, ranging from high-income countries, such as Sweden, to low-income countries, such as India.[2] The research team documented the diet of these individuals at baseline (using questionnaires specific to each country), then followed them up for a median of 7.4 years, looking at cardiovascular-related clinical outcomes. As expected higher intakes of fruit, vegetables and legumes were associated with lower incidences of major CVD, myocardial infarction, and mortality (cardiovascular-related and all-cause). However, the hazard ratio for all-cause mortality was lowest for three to four servings (375-400g) per day (0.78, 95%CI 0.69-0.88), with no significant decrease with higher consumption.

It is more likely that consuming around 375g of fruit/vegetables/legumes per day will be within the financial reach of people living in poorer countries, compared to the various recommendations of 400-800g that are often seen in Europe and North America. Before we ditch that extra snack of carrot sticks, however, it is important to note that factors such as food type, nutritional quality, cultivation and preparation are likely to vary between countries, while other clinical outcomes, such as cancer, were not looked at in this study.

The authors are continuing to enrol more participants, and are hoping to re-examine their results in the future.

— Peter Chilton, Research Fellow


  1. Oyebode O, Gordon-Dseagu V, Walker A, Mindell JS. Fruit and vegetable consumption and all-cause, cancer and CVD mortality: analysis of Health Survey for England data. J Epidemiol Community Health. 2014; 68(9): 856-62.
  2. Miller V, Mente A, Dehghen M, et al. Fruit, vegetable, and legume intake, and cardiovascular disease and deaths in 18 countries (PURE): a prospective cohort study. Lancet. 2017.

Diet and Socioeconomic Status

People looking to lose weight and/or get healthy try a wide variety of diets, from fad diets with highly specific restrictions on what can be eaten, to general healthy eating plans. One such nutritional recommendation is the Mediterranean diet, based on the “food patterns typical of Crete… Greece and southern Italy…”,[1] and entails consumption of high amounts of plant foods (fruit, vegetables, cereals, legumes, etc.) and olive oil, moderate amounts of dairy, fish and wine, and low amounts of poultry and red meat. A number of observational studies have shown associations between such a diet and lower incidences of cardiovascular disease (CVD) and associated mortality, cancer, neuro-degenerative disorders, and overall mortality. However, there is uncertainty whether such benefits differ across different socioeconomic groups.

Bonaccio et al. carried out a prospective analysis of nearly 19,000 Italians to see the effect of the Mediterranean diet on CVD.[2] While there was an overall reduction in CVD risk associated with adherence to the diet (HR=0.85, 95% CI 0.73-0.99), this was not seen across all socioeconomic groups – only in those who were educated to a postgraduate or higher level (HR=0.43, 0.25-0.72) and in those with a high (>€40,000) household income (HR=0.39, 0.23-0.66). Those with less education (HR=0.94, 0.78-1.14) and lower income (HR=1.01, 0.79-1.29) had no significant association. Why such a difference? Subgroup analysis of people with similar adherence to the diet showed that there were a number of differences in the diet of those with high compared to low education, and those with high compared to low income. These included consumption of organic vegetables (which would have higher antioxidants and lower levels of pesticides), monounsaturated fatty acids (found in avocado, nuts, olives, etc.), micronutrients, and whole-grain bread, as well as greater dietary diversity.

So perhaps it is more important to make sure the food you are eating is of high quality and varied, than just simple healthy eating. Of course, access to high quality food of high nutritional value is not easy for poor people.

— Peter Chilton, Research Fellow


  1. Willett WC, Sacks F, Trichopoulou A, Drescher G, Ferro-Luzzi A, Helsing E, Trichopoulos D. Mediterranean diet pyramid: a cultural model for healthy eating. Am J Clin Nutr. 1995; 61(6): 1402S–6S.
  2. Bonaccio M, Di Castelnuovo A, Pounis G, et al. High adherence to the Mediterranean diet is associated with cardiovascular protection in higher but not in lower socioeconomic groups: prospective findings from the Moli-sani study. Int J Epidemiol. 2017.

Using the Internet for More Than Just Cat Pictures

The Internet can be a highly useful tool – communicating with old or distant friends, finding out the latest news, purchasing the latest best-seller, looking at photos of cats, etc. People also go online when they, or someone they know, is ill, searching for information or posting on social media. Your Internet search provider tracks all of this, and this data can be used by researchers to track outbreaks and the spread of infectious diseases. A recent paper by Yang and colleagues [1] demonstrated such a feat with regards to dengue fever.

Dengue is quickly becoming one of the most endemic mosquito-borne disease worldwide, infecting around 390 million people each year in 128 countries,[2] and placing the local health services under immense pressure. The Aedes mosquito that transmits dengue thrives in slums / shanty towns.[3] One of the ways to reduce infection rates is to improve early case detection – identifying outbreaks early means that preventive measures, such as mosquito population control, providing mosquito screens or nets, etc., can be undertaken. However, there is no current surveillance system for dengue that is comprehensive, effective and reliable – governments tend to use reports from hospitals that are often delayed and/or inaccurate.

Yang, et al. combined dengue-related Internet searches with historical incidence data to track dengue activity in five areas, Mexico, Brazil, Thailand, Singapore and Taiwan. They were able to successfully estimate dengue activity one month prior to the publication of official local health records, with their method outperforming benchmark models across accuracy metrics in all areas, except Taiwan. The authors note that Taiwan had little previous dengue prevalence on which to base predictions, suggesting the methodology works best in areas where dengue is already endemic.

— Peter Chilton, Research Fellow


  1. Yang S, Kou SC, Lu F, Brownstein JS, Brooke N, Santillana M. Advances in using Internet searches to track dengue. PLoS Comput Biol. 2017; 13(7): e1005607.
  2. World Health Organization. Dengue and severe dengue. 2016.
  3. Ezeh A, Oyebode O, Satterthwaite D, et al. The history, geography, and sociology of slums and the health problems of people who live in slums. Lancet. 2017; 389: 547-58.

A Novel Drug for Tuberculosis

Once rampant across the globe Tuberculosis has been brought under control, first by improved hygiene standards, and then antibiotic drugs, such as isoniazid and rifampicin, developed in the 1950s and 1960s. However, it remains one of the top 10 causes of death across the world, infecting 10.4 million people and killing 1.8 million in 2015, the vast majority (95%) in low- and middle-income countries.[1] Further, there has been a rise of TB strains that are resistant to antibiotics – around 480,000 people developed multi-drug resistant TB (MDR-TB) in 2015.[1] Of these, only 52% were successfully treated by second-line treatment options, such as extensive chemotherapy. More worryingly, there has been a rise in cases developing extensive drug resistance (XDR-TB), which has very limited treatment options. One of the United Nation’s Sustainable Development Goals is to end the TB epidemic by 2030, but to do this new antibiotics are needed to which no resistance has developed.

University of Warwick researcher Gregory Challis, together with Eshwar Mahenthiralingam and colleagues, recently discovered a promising candidate – gladiolin. [2] Bacteria belonging to the genus Burkholderia are able to thrive in a diverse range of environments thanks to their ability to produce potent antibiotics to remove any competition. Researchers were able to isolate gladiolin by screening one such strain, B. gladioli, that was taken from a child with cystic fibrosis. Gladiolin works by inhibiting RNA polymerase (a validated drug target in TB), has significantly improved chemical stability compared to structurally similar antibiotics, and has low cytotoxicity in mammals. Further research found that while gladiolin was less effective (compared to isoniazid and rifampicin) against strains of TB with no resistance, it had good activity against several strains of TB that were resistant to isoniazid and rifampicin. It is hoped that gladiolin will be the starting point for developing new drugs that can tackle MDR-TB and XDR-TB.

— Peter Chilton, Research Fellow


  1. World Health Organization. Tuberculosis Fact Sheet. 2017.
  2. Song L, Jenner M, Masschelein J, et al. Discovery and Biosynthesis of Gladiolin: A Burkholderia gladioli Antibiotic with Promising Activity against Mycobacterium tuberculosis. J Am Chem Soc. 2017; 139(23): 7974-81.

Effectiveness of Debunking Online

In a recent News Blog we looked at how users of Social Media Sites, such as Facebook, tend not to view information that disagrees with their own ideas.[1] This has been backed up by another recent study by Zollo et al. in PLoS One.[2] Here the authors examined the Facebook activity of 54 million users over five years, and compared how users who usually look at proven, scientific information, and those who look at unsubstantiated, conspiracy-like posts (i.e. not reported in the mainstream media) interacted with specific debunking posts. They found that such users generally existed in ‘echo chambers’, interacting primarily with either scientific or conspiracy-like posts and pages. The authors then focussed on a set of 50,220 debunking posts, and found that around 67% of ‘likes’ and 50% of comments for these pages came from the users who consumed proven information, while only 7% of ‘likes’ and 4% of comments came from those users who viewed unsubstantiated information. Interestingly, the comments made by both groups were mainly negative. Further analysis showed another interesting finding – users of the conspiracy echo chamber who did not interact with debunking posts were 1.76 times more likely to stop interacting with unsubstantiated news in the future – i.e. interacting with debunking posts was associated with an increased interest in unsubstantiated, conspiracy-like content.

The authors suggest that these results support the ‘inoculation theory’ – exposure to repeated, mild challenges to their beliefs leads people to become more resistant to change, even if latter arguments are stronger and more persuasive. Maybe a different approach is needed.

— Peter Chilton, Research Fellow


  1. Lilford RJ. It is Really True: Detailed Analysis Shows That Social Media Really Do Lead to Silo Thinking. NIHR CLAHRC West Midlands News Blog. June 23, 2017.
  2. Zollo F, Bessi A, Del Vicario M, et al. Debunking in a world of tribes. PLoS One. 2017; 12(7): e0181821.

Reducing the Global Burden of Diagnostic Errors

A recent issue of the BMJ Quality and Safety carried an interesting review on the global burden of diagnostic errors in primary care.[1] The review looked at the most common symptoms and conditions affected by such errors; summarised the current interventions; and suggested what could be done next to reduce the global burden of diagnostic errors. The authors found that:

  • Typically there are multiple ‘root causes’ for errors, including both cognitive errors, such as failing to synthesise evidence, and system flaws, such as communication issues.
  • The most common categories of harmful diagnostic errors are infections, cardiovascular disease, cancer, and diseases in children.
  • Very few interventions to reduce errors have been tested empirically.
  • In order to reduce errors successfully there is likely to be a need for multiple interventions.

They go on to propose eight themes for interventions to measure and reduce diagnostic error:

  1. Improving diagnostic reasoning.
  2. Encouraging government policies that support primary care.
  3. Improving information technology.
  4. Involving patients.
  5. Improving access to diagnostic tests.
  6. Developing methods to identify and learn from diagnostic errors.
  7. Optimising diagnostic strategies in primary care.
  8. Providing systematic feedback to clinicians about their diagnoses.

The authors call on the World Health Organization to bring together concerned bodies to address the many challenges that are common across all countries and the opportunities that can be taken to reduce diagnostic error. CLAHRC WM collaborators are working on a more detailed classification system for the theoretical basis for diagnostic error.

— Peter Chilton, Research Fellow


  1. Singh H, Schiff GD, Graber ML, Onakpoya I, Thompson MJ. The global burden of diagnostic errors in primary care. BMJ Qual Saf. 2017; 26: 484-94.

Mindfulness for Low Back Pain

Lower back pain is fast becoming a major public health problem. Perhaps because of our increasingly sedentary life style it affects around 75% of the population at some point during their lives. However, there is no optimum clinical treatment. In light of this, many people turn to complementary therapies. A recent systematic review by Anheyer and colleagues [1] looked at the effectiveness of such a therapy, mindfulness-based interventions. Mindfulness-based stress reduction programmes (MBSR), and mindfulness-based cognitive therapy (MBCT) (see main article) usually involve activities such as meditation, yoga, and focusing attention on different parts of the body. The authors identified seven RCTs involving 864 patients, and found that MBSR was associated with statistically significant short-term improvements in pain, compared to standard care, though these weren’t sustained in the long term, and could not be deemed clinically meaningful. However, there were no significant differences when compared to active comparators, such as health education programmes. These were only a limited number of RCTs and there is still a need for long-term RCTs that compare MBSR against active treatments.

— Peter Chilton, Research Fellow


  1. Anheyer D, Haller H, Barth J, et al. Mindfulness-based stress reduction for treating low back pain. A systematic review and meta-analysis. Ann Intern Med. 2017; 166: 799-807.