Question

trends. We're all being impacted some way but COVID- 19, and as it progresses we can find more effective ways for treatment and/or prevention. By the end of this week you would have read about descriptive, analytic, or case control studies. If you were asked to implement one of these to understand the trends, exposure, and treatment of this virus (or even another hypothetical one), what are some elements which need to be considered? How much data would you need (i.e. is there a min/max of persons within a population that are needed?) What kind of calculation would you use (Odds Ratio? case report?). Please describe what aspect of studying this virus would interest you the most and how you would set up a study design to better or understand or slow down its progress. (And if you find anything groundbreaking let us know!)

Answer 1

Covid 19 infection is an outbreak ,started in china and now became pandemic.Till now no effective treatment known.So we need to study further details about this virus ,its source,mode of transmision,incubation periods, symptoms, consequences,... so that we can identify infection early and take appropriate precautions. But for getting these information we have to do study, mainly the people already affected by this virus,so that we will know more exact details of this infection.Appropriate study for this infection is retrospective study ,that is case control study. In this we are taking cases and controls. Cases are those who are having disease already, and control are those not having disease, and we are asking questionaire to these two groups to find out the risk factors for developing the disease.

Retrospective study is mainly for rare disease ,and is very fast,in expensive. can study multiple exposure, it requires few study subjects,

Disadvantage of these study are , cannot generate incidence data, chances of bias like recall bias, investigator bias...,selection of control is difficult, if records are not available it is difficult.

In case control study , strength of assosiatio between exposure and outcome can be find out by odds ratio., calculated as odds of an exposure in the case group to the odds of an exposure in the control group.

	CASES	CONTROL	TOTAL
EXPOSED	a	b	a+b
UNEXPOSED	c	d	c+d
TOTAL	a+c	b+d	a+b+c+d

Odds Ratio = ( a/c) /(b/d)

= (a*d) / (b*c)

We should study the genomic aspect of virus , its multiplication mechanisms, factors required for the multiplications, what factors will prevent its multiplication, exact way of transmision, orgin of virus , preventing the spread of virus to more people is the best way to prevent this disease, self clean with sanitizers, avoid frequent touching face, eyes, nose, those who suspected of having infection get medical help and  stay in isolation .