It may be good to include that Bradford Hill himself presented this as viewpoints, rather than criteria. In his own writing, he made explicit that none of these viewpoints can be considered irrevocable evidence of causality, nor can they be seen as a sine qua non.
To present them as "criteria" may enhance the misnterpretation that they should be seen as evidence for causality.
The book "history of epidemiological methods and concepts" includes some very insightful and educational quotes from Bradford Hill on these viewpoints. I will try later this week to include them in this chapter (as soon as I get behind a desktop computer, since this is written from my iPad)
List of useful websites for mapping. First, a list of websites from which you will be able to download map files:
Then, two useful websites to access and create maps:
Advice thanks to Marc Rondy ("EAN GIS Mini module" 2012)
So here we see that the relative risk is synonymous to risk-ratio. Funny enough, we do not speak of a 'relative rate', yet only of a rate-ratio.
We could debate whether or not we are able to 'measure' a causal effect. In my view, what we measure are observations (counts) expressed in numbers, rates, risks for example.
The comparison is already a computation, resulting in an 'effect', which caj be consided an estmation of the effect in the population.
If the effect (e.g. measure of association) is causal or not, cannot be measured, not tested. It can merely be inferred.
According the discussion during this session with Luise from Denmark, I believe we need to add one important item :
1.a Is there a clear research question?
Identifying essential infection control competencies for newly graduated nurses: a three-phase study in Australia and Taiwan, L.-M. Liuemail address, J. Curtis, P.A. Crookes, Journal of Hospital Infection, Volume 86, Issue 2 , Pages 100-109, February 2014
ConclusionEighty-one items of infection prevention and control specific to newly graduated nurses were identified by consensus between expert panelists from Taiwan and Australia. Baseline data from this study may help to develop undergraduate nursing curricula to facilitate nurses' clinical application of infection control principles.
Software collection amongst EPIET Facilitators and Fellows collected at the introductory course 2013 in Spetses
Does rhis include chronic disease?
One of the developments in the past decade is that the concept of 'an outbreak investigation report' is stretching and evolves.
With the use of internet, social media, rapid alert systems, the different target audiences of outbreak investigations require different formats.
Even when within 2 weeks a solid preliminary outbreak report is published in a public health journal, including hypotheses, methods, results and conclusions, then this may still be too late for some target groups of 'those who need to know'.
Websites of national and international public health institutes and agencies are being scanned daily by public health professionals in search of pieces of evidence that they can use in their daily professional decisions. More and more we seem to move to 'incremental online outbreak reports', where almost daily updated threat assessments aim to give the latest of knowledge and evidence in terms of risk groups and risk factors.
Epidemiologists therefore also need to adapt their way of working in terms of scientific output to address this evolving demand of reliable, sound, objective and structured information about ongoing outbreaks
More and more we see internet as a key medium to perform epidemic intelligence tasks. Should this be mentioned in the core competencies?
On 15 of March 1813, John Snow was born in York, England; an English physician and a leader in the adoption of anaesthesia and medical hygiene. Snow is considered to be one of the fathers of Field Epidemiology, because of his work in tracing the source of a cholera outbreak in Soho, England, in 1854.
On 15 March 2013 is a good opportunity to focus attention of our public health colleagues and of the general public, on the importance of the work of modern field epidemiologists. Our world has become more crowded and differences between those who have good sanitation and those who have not have never been so large.
Even in countries with relatively good sanitation, field epidemiologists are essential to continuously detect health threats, make assessments based on application of sound methods and principles, in order to inform decision takers to make the appropriate actions.
Please add in the thread your ideas about how you can make this more visible in your own community.
Is the month in last graph correctly written?
I'm sharing a link to a free software for Epidemiological Time Series, particularly to extract seasonal parameters from time-series, examine trends and identify unusual periods (for example epidemic peaks).
Hope you find it of interest!
OJE published "Case-control studies: basic concepts"
Abs: The purpose of this article is to present in elementary mathematical and statistical terms a simple way to quickly and effectively teach and understand case-control studies, as they are commonly done in dynamic populations-without using the rare disease assumption. Our focus is on case-control studies of disease incidence (‘incident case-control studies'); we will not consider the situation of case-control studies of prevalent disease, which are published much less frequently.
Ref: Jan P Vandenbroucke and Neil Pearce: Case-control studies: basic concepts Int. J. Epidemiol. (2012) 41(5): 1480-1489 doi:10.1093/ije/dys147 http://ije.oxfordjournals.org/content/41/5/1480.full.pdf+html
This week a very readable article appeared in Eurosurveillance on this topic. Olivier le Polain de Waroux and his co-authors do a great job describing and explaining the principles of case-cohort, with very useful examples.
I can invite everyone to read this piece:
Le Polain de Waroux O, Maguire H, Moren A. The case-cohort design in outbreak investigations. Euro Surveill. 2012;17(25):pii=20202. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=20202
I am a little bit confused. According Czech definition source of infections can be human, animal , or enviromental in origin ( only for legionela or some kind of mycobacterium).
Food , watrer etc are vehicles of infection.
Your example with a chocolate cake .... cake is vehicle, eggs used are vehicles and hen is source.
Who first defined the source of infection?