The report by Gill Livingston and colleagues (Dec 16, 2017 p 2673)1 is a valuable collation of a large body of medical research evidence that aims to combat the dementia epidemic, the greatest global challenge for health and social care in the 21st century. One of the key messages of the Commission is the need to be ambitious in terms of prevention. Using population attributable fractions (PAF), the authors estimate that as much as 35% of dementia cases could be prevented by targeting nine modifiable risk factors.

The Lancet Commission (Dec 16, 2017, p 2673)1 on prevention and management of dementia reviews the mounting evidence that hearing loss is a major risk factor for cognitive decline. Crucial information is still absent about the nature of this linkage and what factors might modify the cognitive effect of peripheral hearing loss. Particularly, the potential relevance of central hearing impairment should not be underestimated. As Gill Livingston and colleagues1 acknowledge, on pathophysiological and neuroanatomical grounds, central auditory processing is likely to be susceptible early in the course of Alzheimer's disease and other dementias.

We welcome the opportunity to respond to the letters about The Lancet Commission1 on dementia prevention, intervention, and care.

Cohen AJ, Brauer M, Burnett R, et al. Estimates and 25-year trends of the global burden of disease attributable to ambient air pollution: an analysis of data from the Global Burden of Diseases Study 2015. Lancet 2017; 389: 1907–18—In this Article (published online first on April 10, 2017), the mathematical form for the IER has been corrected. This correction has been made to the online version as of April 19, 2018.

Chen I, Cooney R, Feachem RGA, Lal A, Mpanju-Shumbusho W. The Lancet Commission on malaria eradication. Lancet 2018; 391: 1556–58—In this Comment (published online first on April 16, 2018), the affiliation for Winnie Mpanju-Shumbusho should be RBM Partnership to End Malaria, and the weblink should be RBM Partnership to End Malaria. These corrections have been made to the online version as of April 19, 2018, and the printed Comment is correct.

20 years ago, infectious diseases dominated the global health agenda. Policy makers, researchers, implementers, and donors united in the fight against infectious diseases, creating the Millennium Development Goals, the Global Fund to Fight AIDS, Tuberculosis and Malaria, Gavi, the Vaccine Alliance, the US President's Emergency Plan For AIDS Relief (PEPFAR), the Roll Back Malaria Partnership, the Multilateral Initiative on Malaria (MIM),1 and more. Tremendous progress was made. Malaria benefited spectacularly and there has been a 47% reduction in global deaths from the disease since 2000.

The most recent estimates by the World Economic Forum indicate that the global economic gender gap will take 217 years to close, and that this gap widened in 2017. That pay inequality is pervasive in the UK is therefore unsurprising. The UK median gender pay gap—the difference in average hourly earnings between men and women—is 18%. To address this disparity, the UK became the first country to mandate individual employers to release their gender pay gap data. All public and private sector employers with at least 250 employees had to report by April 4, 2018.

On March 28, the tragic case of Jack Adcock—a 6-year-old boy with Down's syndrome who died of sepsis in Leicester Royal Infirmary in 2011—and Dr Hadiza Bawa-Garba took another turn. Bawa-Garba, the paediatric trainee convicted of gross negligence manslaughter by a jury in 2015, was given permission to appeal a January High Court ruling to permanently strike her off the medical register. The General Medical Council (GMC), the UK's licensing body for doctors, had successfully appealed its own but independent Medical Practitioners Tribunal Service's decision from last July to suspend the doctor for 12 months but not revoke her licence.

After nearly two decades of progress following the abolishment of apartheid, South Africa's societal gains are now deteriorating. These are the conclusions of a report published on March 28 by The World Bank that analysed the country's progress in reducing poverty and inequality from 1994 to 2015. While overall the country's poverty levels have fallen since 1994, at least 2·5 million more South Africans since then have become poor. Over half the population lives under the poverty line, many of whom are black or South Africans of mixed race.

Guidelines for levels of alcohol use that pose a low risk to drinkers' health are provided by many countries, usually based on meta-analyses of epidemiological studies.1–3 However, to devise such guidelines is challenging because alcohol is linked to poor health in various and complex ways. Injury, suicide, and assault, for example, are associated with drinking to intoxication, whereas regular alcohol consumption increases the risks of liver cirrhosis, gastrointestinal diseases, cardiovascular disease, dementia, and some types of cancer.

Humanities and social sciences have had many positive influences on health experiences, care, and expenditure. These include on self-management for diabetes, provision of psychological therapy, handwashing, hospital checklists, the Scottish Government's stroke guidelines, England's tobacco control strategy, the response to the Ebola outbreak in west Africa and Zika virus in Brazil, and many more.1 Researchers have shown time and time again the political, practical, economic, and civic value of education and research in disciplines like anthropology, history, and philosophy.

How did it happen that palliative care lost the dignity debate? Palliative care is a discipline dedicated to improving quality of life by preventing and alleviating suffering. There can be few higher callings in medicine. Yet those who advocate “dignity in dying” have successfully claimed that the idea of dignity lies not in palliative care but in assisted dying for the terminally ill. A large majority of the public seems to agree. Those in favour of assisted dying have portrayed palliative care as somehow antithetical to patient autonomy.

Ireland has set a date for a referendum that could be decisive in women's access to abortion. Anita Makri reports on the arguments on both sides of the debate.

Cultural mediators can help migrants, asylum seekers, and refugees to face what can seem an insurmountable wall of cultural difference. Amanda Sperber reports from Polistena.

Obesity and the diseases that are related to it are at the core field of Sydney's Charles Perkins Centre, led by a man whose first area of research was locust behaviour. Stephen Simpson says his own varied background shows why this research body is different.

For early modern physicians syphilis was “the great imitator”, a disease that mystified with the sheer range of its symptoms and the length of time it might take to show itself. Syphilis was first recorded in Europe in the mid-1490s, and the coincidence with Christopher Columbus' first voyage to the New World led contemporary physicians (along with more recent archaeologists and historians) to conclude that his sailors had brought the disease back with them.

There have been times when I've said that if I ended up meeting my teenage self, due to some bizarre time-travel mishap, I'd probably end up trying to strangle the arrogant, bungling, self-absorbed waste of space that he was. I've heard other people echo similar sentiments. It's weird how so many think so little of their adolescent selves, from their older, more mature perspective. How can we change so much and yet remain the same person? And why were we like that, consumed with all the neuroses and priorities that as adolescents were so vital but now just seem ridiculous, or baffling, or even a little sad?

If determination is a predictor of future achievements in medical research, the likelihood that Professor Guo-Qiang Chen would have a flourishing career should have become apparent when he was still a very junior doctor. To leave the provincial medical school to which he was then contracted and relocate himself to a distant and more research-oriented institution, he had to find the money to take on a major debt. It was, as he himself admits, “a gamble”. Now, some 25 years later, Chen is a member of the Chinese Academy of Sciences, Chancellor of Shanghai Jiao Tong University School of Medicine, and Director of its Laboratory of Cell Differentiation and Apoptosis.

Death has become quite modish, and being constantly aware of one's mortality is now regarded as an essential component of spiritual and psychological health. My book The Way We Die Now was published in 2016, and since then I have given many talks and written several articles on the subject of death. I am often asked whether all of this talking and writing about death has prepared me any better for my own demise.

Public health expert who directed the US Fred Hutchinson Cancer Research Center. Born in Framingham, MA, USA, on Oct 22, 1930, he died from lung cancer on Jan 6, 2018, in Seattle, WA, USA, aged 87 years.