Counterpoint: Epidemiology's Dual Social Commitment-Science and Health.

Matching epidemiology's aspirations to actual delivery of goods valuable for population health depends both on the scientific and operational capabilities of epidemiology and on the degree to which the goods meet its contract with society. Epidemiology's capabilities have advanced remarkably in recent decades, although research gaps have appeared during the current coronavirus disease 2019 (COVID-19) pandemic. Epidemiology's social contract reflecting a dual commitment to science and health could arguably be entirely met by producing research results under conditions variously described as objective, impartial, neutral, or independent and handing such results to decision makers and the public at large. However, a closer examination shows that those four terms address sharply distinct issues, with distinct practical implications, and that the epidemiologist responsibility is de facto involved beyond providing research results. Hence the epidemiologist's engagement should encompass arguing from a science-for-health viewpoint and proactively driving the results into decision processes on public health issues.

Effect of national and local lockdowns on the control of COVID-19 pandemic: a rapid review.

OBJECTIVES: to describe and compare the effectiveness of national and local lockdowns in controlling the spread of COVID-19. METHODS: a rapid review of published and grey literature on COVID-19 pandemic was conducted following predefined eligibility criteria by searching electronic databases, repositories of pre-print articles, websites and databases of international health, and research related institutions and organisations. RESULTS: of 584 initially identified records up to 5 July 2020, 19 articles met the inclusion criteria and were included in the review. Most of the studies (No. 11) used the reproduction  number (Rt) as a measure of effect and in all of them areduction of the estimated value at post-intervention period was found. The implementation of lockdown in 11 European countries was associated with an average 82% reduction of Rt, ranging from a  posterior Rt of 0.44 (95%CI 0.26-0.61) for Norway to a posterior Rt of 0.82 (95%CI 0.73- 0.93) for  Belgium. Changes in infection rates and transmission rates were estimated in 8 studies. Daily changes in infection rates ranged from -0.6% (Sweden) to -11.3% (Hubei and Guangdong provinces). Additionally, other studies reported a change in the trend of hospitalizations (Italy, Spain) and positive effects on the  doubling time of cases (Hubei, China) after lockdown. CONCLUSIONS: results of this rapid review suggest a positive effect of the containment measures on the spread of COVID-19 pandemic, with a major effect in  countries where lockdown started early and was more restrictive. Rigorous research is warranted to evaluate which approach is the most effective in each stage of the epidemic and in specific social contexts, in particular addressing if these approaches should be implemented on the whole population or target specific risk groups.

Cancer mortality in an international cohort of reinforced plastics workers exposed to styrene: a reanalysis.

OBJECTIVE: To investigate the carcinogenicity of styrene by reanalysing data from a previous international cohort study of workers in the reinforced plastics industry. METHODS: Mortality from cancers of prior interest was analysed with more detailed consideration of exposure-response relations and an updated classification of leukaemias and lymphomas in data from a previous international cohort study of 37 021 reinforced plastics workers exposed to airborne styrene. RESULTS: Increased mortality from non-Hodgkin's lymphoma (NHL) was associated with the mean level of exposure to styrene in air (relative risk (RR) 2.31, 95% CI 1.29 to 4.12 per 100 ppm), but not with cumulative styrene exposure. Similar associations with mean exposure were observed for the oesophagus (RR 2.44, 95% CI 1.11 to 5.36 per 100 ppm) and pancreas (RR 1.89, 95% CI 1.17 to 3.09). Oesophageal cancer mortality was also associated with cumulative styrene exposure lagged 20 years (RR 1.16, 95% CI 1.03 to 1.31). No other cancer, including lung cancer, was associated with any indicator of styrene exposure. CONCLUSION: This reanalysis does not substantially change the conclusions of the original study with respect to NHL or lung cancer but new evidence concerning cancers of the oesophagus and pancreas merits further investigation.

Epidemiology in wonderland: Big Data and precision medicine.

Big Data and precision medicine, two major contemporary challenges for epidemiology, are critically examined from two different angles. In Part 1 Big Data collected for research purposes (Big research Data) and Big Data used for research although collected for other primary purposes (Big secondary Data) are discussed in the light of the fundamental common requirement of data validity, prevailing over "bigness". Precision medicine is treated developing the key point that high relative risks are as a rule required to make a variable or combination of variables suitable for prediction of disease occurrence, outcome or response to treatment; the commercial proliferation of allegedly predictive tests of unknown or poor validity is commented. Part 2 proposes a "wise epidemiology" approach to: (a) choosing in a context imprinted by Big Data and precision medicine-epidemiological research projects actually relevant to population health, (b) training epidemiologists,

The hazards of hazard identification in environmental epidemiology.

Hazard identification is a major scientific challenge, notably for environmental epidemiology, and is often surrounded, as the recent case of glyphosate shows, by debate arising in the first place by the inherently problematic nature of many components of the identification process. Particularly relevant in this respect are components less amenable to logical or mathematical formalization and essentially dependent on scientists' judgment. Four such potentially hazardous components that are capable of distorting the correct process of hazard identification are reviewed and discussed from an epidemiologist perspective: (1) lexical mix-up of hazard and risk (2) scientific questions as distinct from testable hypotheses, and implications for the hierarchy of strength of evidence obtainable from different types of study designs (3) assumptions in prior beliefs and model choices and (4) conflicts of interest. Four suggestions are put forward to strengthen a process that remains in several aspects judgmental, but not arbitrary, in nature.

[Epidemiology, «liaisons dangereuses¼, and public health]. / Epidemiologia, «liaisons dangereuses¼ e sanità pubblica.

Two recent articles in the French daily Le Monde raised the issue of conflicts of interest with specific reference to the case of an Italian epidemiologist nominated for a key position in a French public institution. The issue can be seen - and is here discussed - from the angle of the social role of scientists, in particular epidemiologists. The viewpoint developed is that epidemiologists having key responsibilities in public institutions, whose mission is not only to carry research but to channel its results into the process of public health decisions, are akin practicing clinicians who are also involved in research. Their social role, and what the public expect of them, is to orient their research and interpret the unavoidable uncertainties of the results in a way that maximizes benefits and minimizes risks to people's health. Being directly or indirectly involved in practical decisions at clinical or public health levels, they cannot be "neutral" in respect to health, as a researcher could be. This viewpoint is particularly relevant in respect to the doctrine maintaining that false positive results are today the dominant methodological issue in epidemiology and consequently avoidance of decisions based on possibly false positive results is the top priority in all circumstances. In fact, depending on the specific circumstances, this may turn out contrary to the principle of maximizing benefits and minimizing risks to people's health, hence the "doctrine of false positives" is erroneous for epidemiologists working in public institutions with responsibilities for translating research into actions.

["Reversing" the teaching of medicine, yesterday and today]. / "Capovolgere" l'insegnamento della medicina, ieri e oggi.

Recently the radical critique has been revived of medicine teaching developed some fifty years ago by G.A. Maccacaro with special focus on Italy. He maintained that a dominating biological perspective obscured all social dimensions of health and disease, educating doctors poorly equipped to grasp the practical relevance of social determinants of diseases and to correctly perceive their own role in society. In fifty years, many aspects of the practice of medicine have however changed: how such changes relate to the current teaching of medicine? Three key developments have taken place. First, separate specialties and subspecialties have multiplied at fast pace, and teaching has usually favoured this increasing fragmentation. Second, in actual practice doctors need to overcome disciplinary segmentation and collaborate, often to a substantial extent: little trace of how best to implement this is present in academic teaching. Third evidence-based medicine and guidelines for preventive, diagnostic and therapeutic interventions have become common currency in medicine: teaching of these topics is, notably in Italy, in general weak, leaving future doctors unprepared to a critical understanding and use of evidence-based medicine and guidelines in the daily practice. Substantial changes in medical teaching appear needed today no less than fifty years ago, but they can only start from a recognition of medicine as it stands today rather than fifty years ago.

[Solidarity, covid-19 and a lever without fulcrum.] / Solidarietà, covid-19 e una leva senza fulcro.

Herd, or collective, immunity has been a permanent reference all along the Covid-19 pandemic, often misunderstood as a technical synonym of "epidemic end" once a threshold value of immunized people is reached. The pandemic development has shown that with current variants transmissibility and current vaccines such critical threshold cannot be reached. An effective collective immunity is however attainable, the stronger the higher the population proportion of vaccinated people. This immunity, a powerful brake on the epidemic progression, depends on the degree of solidarity that society enacts as a whole via containment measures (physical distancing, masks) and vaccination. A clear solidarity deficit is manifest within countries in the form of repeatedly delayed adoption of correct interventions against the epidemic and between countries with the heavy shortage of vaccines in countries with low and middle-low income. The lever of counter epidemic actions by governments and health authorities cannot operate without the support of a fulcrum of civic solidarity: it depends only on citizens, individually and collectively, to build it small stone upon stone.