Lets briefly discuss some of the basic concepts of #epidemiology that may be important in discussing #COVID19

1. Epidemiological triad
2. Evidence based medicine/healthcare
3. Good science vs bad science

The epidemiological triad is a simple model that explains disease causality.

a. agents of disease could be either infectious organisms (bacteria, fungi, virus) or exposures such as chemicals, smoking, foods, toxins

Generally, the agent should be present b4 disease occurs.

b. The host offers an ecosystem for the agent to thrive and cause disease. This usually represents the person.
May factors affect the host's vulnerability to (1) infection and (2) poor outcomes from the disease.

These could be biological or social determinants

c. The environment also plays a part and in some diseases, is intricately linked with social determinants of health. For example, a homeless person is likely to get #COVID19 due to their environment and their inability to buy and face masks, buy and use soap and sanitizers

Again, bear in mind that there are other models of disease causality and these are constantly being refined

The concept of evidence based medicine/healthcare (EBM) is a huge concept.

In summary,EBM is the use of the latest and best evidence, together with a patient preferences and the best clinical judgement.
The principle has been expanded to public health and other health sciences

The two parts of EBM (patient preference and best clinical judgement) are less difficult to deal with than the issue of evidence.

You may also sub "patient" for community or even whole populations

Now, you may ask,
1. What constitutes good evidence?
2. Who decides this is good evidence?
3. Who generates the evidence

for EBM

Anyone with access to research infrastructure may generate research evidence. But usually clinicians and researchers do

Using #COVID19 as an example,

One can immediately see the problem here. 10 000 research articles on COVID in less than 4 months. An avalanche

Part of the process of EBM answering question 1, which deals with separating the wheat from the chaff.

This involves understanding how best evidence should be generated and being able to critically appraise the published research for bias

Apart from the exponential growth in research evidence published, the growth of open access publishing has also increased access to research findings for everyone rather than people within particular specialties.

The so-called predatory journals have also complicated matters

….Rubbish associations find themselves in daily headlines, some bordering on the ridiculous.

It is possible for research to do harm . Here are some ways that bad science can come up.

The main aim of EBM is to be able to judge the scientific merit of a treatment/ intervention based on the research that is presented

Here is a short video from Ben Goldacre about #badscience