While organised mammography screening programs were being gradually introduced across various countries, researchers could study the impact of screening on breast cancer mortality by comparing mortality in areas with and without screening. Now that screening has been fully implemented in most Western countries, researchers can only compare women who participate in screening with those who do not participate.
Women who do not participate in screening may seem to be a good choice as a comparison group, as they are not affected by screening. But the question is: can non-participants reflect how breast cancer mortality would have developed in women in general without the introduction of screening?
We need to be cautious. It is not the virus that leads to interstitial lung disease and death. It is our immunological response, the “cytokine storm”, that causes severe illness.
This is comparable to the devastation of the respiratory syncytial virus, persistently responsible for bronchiolitis in the very young, killing tens of thousands worldwide each year.
If the vaccine is both effective and safe, enough people will be immune, and transmission from them to the rest of us will be much diminished. Indeed, if enough people are immune — generally about 60% (“herd immunity”) — either through exposure or vaccination, transmission ceases.
The Council of the International Epidemiological Association, its affiliate bodies and members have viewed with concern the rapidly evolving situation with the novel Coronavirus (COVID-19) pandemic. Since the onset of the outbreak in December 2019, this disease has affected 162 countries and territories (as of 17/03/2020) with over 184,000 people affected and 7,000 deaths. With countries at various response stages of anticipation, early detection, containment, and mitigation, we commend the efforts of the WHO, various national governments, non-governmental organizations, health workers and advocates in addressing this health crisis.
If COVID-19 were allowed to spread unchecked, it would devastate Australian society. My modelling suggests that Australia could get as many as 400,000 to 600,000 infections a day at the peak – translating to about 150,000 to 200,000 symptomatic cases a day. There’s no way we can let the numbers get that high. It would be absolute carnage.
Ka Hung Chan, Derrick Bennett, Kin Bong Hubert Lam and Zhengming Chen
Chronic liver diseases (CLD), such as liver cirrhosis and liver cancer, affect more than 800 million people worldwide, with a third of these living in China. Smoke from solid fuels (e.g. coal and wood) and tobacco contains high concentrations of thousands of toxic chemicals. When breathed in, these chemicals can reach and harm major internal organs, including the liver.
Ding (Melody) Ding, Adrian Bauman, Esther van Sluijs and Klaus Gebel
Have you ever had this experience? You’re looking into the literature on the association between an exposure (such as accelerometer-measured physical activity) and an outcome (such as all-cause mortality) and, you find six papers, not one, written by the same authors based on the same sample. “Are these the same paper?”, you wonder. On careful perusal of the titles and abstracts, you realise that these are different papers on similar and related research questions, only with minor differences: one looks at the association in men, another in women, a third one in older adults, a fourth in a subsample with a pre-existing condition …
We are all familiar with studies that investigate the associations between physical activity and outcomes such as death or cardiovascular disease. However, we rarely focus on the length of time over which these study participants are followed up to see if one of the outcomes occurs.
For children in low-income countries, diarrhoea
remains a major cause of death and can lead to long-term health consequences. Accurate
estimates of childhood diarrhoeal illness are crucial to evaluating the success
of campaigns to defeat diarrhoea and improve health in countries where the
burden of diarrhoea is high.
In our study, recently published in the IJE, we found that caregivers may underestimate diarrhoeal diseases in children aged under 5 years when asked to recall whether the children had diarrhoea in the previous 2 weeks. Compared with a 1-week recall period, there was a consistent underestimation of the prevalence of diarrhoea across five countries in sub-Saharan Africa.
Suman Chakrabarti, Md Tajuddin Khan and Samuel Scott
Respiratory infections are the most common
chronic disease in children globally and a leading cause of death in developing
countries. This situation is exacerbated by air pollution.
Air pollution in northern India, mainly New Delhi and the neighbouring states, is exacting a toll on the health of residents, making global headlines and highlighting the severity and extent of this public health disaster in one of the world’s fastest-growing economies.
A contributory factor to air pollution in northern India is the harmful practice of crop residue burning — when farmers burn the crop residue to clear fields before sowing a new crop. Although banned by the Indian government in 2015, this practice remains prevalent in many parts of the northern Indian states of Punjab, Haryana and Uttar Pradesh.
Over an average week, adults in the United
Kingdom living with chronic disease spend 61 minutes (9%) less on moderate
activity — such as gardening, brisk walking and housework — and 3 minutes (11%)
less on vigorous activity — such as running and aerobics — than their healthy peers.
Perhaps this comes as a surprise. After all, few of us would question the health benefits of keeping moving and getting our heart rate racing. Physical activity guidelines, such as those developed by the UK’s National Institute for Health and Clinical Excellence, specifically refer to the importance of increasing physical activity for chronic disease management.
So why have we observed a gap in activity
levels between those living with chronic disease and those without?