Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Patients affected by COVID-19 should be treated according to the severity of their disease. However, not all key national or international organisations define severity in the same way. This imprecision in severity assessment compromises the validity of some therapeutic recommendations. Using individual patient data would better guide and improve therapeutic recommendations for COVID-19.

Two health care workers in PPE on a ward

WHO's guidelines for the treatment of COVID-19 are based on the combined analyses of published randomised control trials (RCTs), using statistical methods that allow for the comparison of various treatments between studies.

IDDO researchers reviewed 81 studies included in the WHO COVID-19 analysis and compared their severity classifications with those used by another international COVID network. The two were the same in only 35% of trials. Of the RCTs evaluated, 69% were considered by the WHO group to include patients with a range of severities. The distribution of disease severities within these groups usually could not be determined, and data on the duration of illness and/or oxygen saturation values were often missing.

The published literature contains a wide variety of COVID-19 severity threshold criteria, definitions and categories. Many of these are arbitrary and to add to the confusion, during the course of the pandemic some of the definitions were changed. Often, the key measures of severity were not reported at all and when they were, they were frequently incomplete or ambiguous.

This imprecision in severity assessment compromises the validity of some therapeutic recommendations. Crucially, it shows that the extrapolation of “lack of therapeutic benefit” shown in hospitalised severely-ill patients on respiratory support to ambulant, mildly-ill patients should not be done. To address these issues, the researchers recommend using individual patient data (IPD) to guide and improve therapeutic recommendations for COVID-19.

The full story is available on the IDDO website

Read the publication 'Definitions matter: Heterogeneity of COVID-19 disease severity criteria and incomplete reporting compromise meta-analysis' on the PLOS website

Similar stories

Study finds almost two-thirds of patients are systematically excluded from drug trials

A new WWARN study has found that nearly two-thirds of the malaria-positive patients who present to health facilities are systematically excluded from “classical” anti-malarial treatment efficacy trials.

New antibiotic combination speeds recovery from severe scrub typhus, which infects 1 million people per year

Treating patients ill with severe scrub typhus – a life-threatening infection that kills tens of thousands of people a year - with a combination of intravenous antibiotics doxycycline and azithromycin is significantly more effective than the current monotherapy of using either drug alone, say researchers in a study published in the New England Journal of Medicine (NEJM).

Watch our webinar - Radical cure of vivax malaria: can we do better?

The three presentations and expert discussion by Dr Rob Commons, Dr Alison Roth and Dr James Watson, chaired by Professor Sir Nicholas White (Mahidol Oxford Research Unit) and Dr Chau Nguyen Hoang (Oxford University Clinical Research Unit), are now available.

Study supports evidence ivermectin not effective to treat COVID-19

21 Feb 2023 Oxford UK - High doses of the drug ivermectin, controversially recommended by some high-profile political and media figures during the COVID-19 pandemic, is ineffective at treating the COVID-19 virus, say University of Oxford-affiliated researchers in a study published today in eLife.

Shobhana Nagraj, Women in Science

Clinical Researcher Shobhana Nagraj, from the Health Systems Collaboratives in Oxford, tells us about the female role models who inspired her to follow her dreams

Phase II Malaria vaccine trial begins in Thailand

The Mahidol Oxford Tropical Medicine Research Unit (MORU) has begun a Phase II trial to demonstrate that R21/matrix M is well-tolerated and immunogenic when administered with the antimalarial drug combination.