COVID-19 Tutorial: What Studies to Trust and Which to Avoid?

What’s the difference between observation studies and experimental studies? Watch here for a quick tutorial. 

Published11 May 2020, 10:56 AM IST
4 min read

Video Editor: Kunal Mehra

Observational study, latest clinical trial, it's pre publication, it's cohort..... what?

Ever since COVID 19 has sent the world into a lockdown, we've had a series of news reports about 'exciting new studies' hitting our screens everyday. And because any study that offers a way out seems worth reading about, almost everyone is glued to these news items.

But what does it all mean? Which study should you take seriously and which should you be cautious about?

Watch the video for a quick break down.

Types of Studies:

Recently it was announced that the Indian Council of Medical Research or the ICMR is carrying out an observational study on the impact of anti-malarial drug hydroxychloroquine (HCQ) as a prophylactic drug for COVID-19 at AIIMS in New Delhi.

So, what is an observational study? It means that the ICMR is going to analyse the drug's effects on people who are already taking it.

An experimental study, by contrast, would be if HCQ was introduced to a random sample to study its effects as a prophylactic or treatment option.

Each study has its own strength and weakness and often depends on what question it;s trying to answer. Sometimes, it can be unethical to expose a population to a certain disease just to study the effects of a drug and so observation studies can help. However the problem with observational studies is that its harder to control the variables – for example, yes all the people in the above study to test for prophylactic were healthcare workers, but what other similarities are there?

“We are not doing a trial and we don’t have sufficient evidence base to do a trial. We are also trying to understand the side effects of HCQ.” Says Dr Raman R Gangakhedkar, head of epidemiology and communicable diseases division at ICMR.

Here, Dr Raman is referring to a clinical trial. Before this, however, comes a stage in between: preclinical trials where more data on safety, feasibility and efficiency is tested to ensure the drug is ready for clinical animal and human trials. Clinical trials often occur in phases, with a small sample size at first and then a larger one with escalating doses.

What Are Clinical Trials?

Let’s use another study to understand. World over, the antiviral medication, Remdesivir, is cropping up in headlines as the new ‘treatment’ to this devastating disease. While promising, lets see what the data says and if its too soon to be optimistic.

ICMR’s Dr Gangakhedkar said the drug which was used during the Ebola outbreak may inhibit the SARS-CoV-2 replication and research on its efficacy in the treatment of COVID-19 is a part of the WHO's 'solidarity trial.' This is the WHO's effort to find a treatment through an international clinical trial, the rationale is: The more countries participating, the faster results will be generated.

"Recently reported study on use of remdesivir for COVID-19 treatment is not a clinical trial, but an observational study which found that 68 per cent or two out of three patients after treatment with the drug did not require ventilator support or their need for oxygen support reduced, " he said.

The observational study was published in the New England Journal of Medicine and lead author Jonathan Grein said, “We cannot draw definitive conclusions from these data, but the observations from this group of hospitalised patients who received remdesivir are hopeful.”

The next stage would be to move on to clinical trials. These are trials or tests to try and find out the effectiveness and safety of the drugs by looking at their effects on large groups of people. Generally the subjects would be divided in at least 2 groups: one with the drug and one that doesn’t receive the treatment and acts as a control group.

Two studies are being conducted by Gilead Manufactorers in areas with a high prevalence of COVID-19 in the United States, Asia and Europe. A randomised global trial, enrolling around 800 people, has also been initiated by the US National Institute of Allergy and Infectious Disease on 21 February.

The more times data is tested, and the larger and more randomized the sample, the better we can know if the drug is truly effective.

Virologists called a randomised controlled trial a gold standard of testing drugs and medicine.

But these trials mentioned above are NOT controlled trials - Why?

In the current scenario where people are dying, it may be unethical to have a control group – that is one group that does not receive the treatment. But without effective data how can we prescribe the drug to a large number of people with varying health conditions, ages, and geographies that all factor in?

This is uncharted territory and often the best thing is to test more for more concrete evidence.

Steps to Check for a Robust Study

  1. First, check what stage of research it is at: clinical studies on a wide population which provide consistent data.
  2. Second, check if it is peer-reviewed and analysed by other scientists in the field.
  3. Third, check if it is published in a verified journal.

Drug trials don’t always need to follow the same pattern, and in an unprecedented situation like a pandemic, it’s careful to keep misinformation, panic and early celebration at bay and wait for conclusive results.

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