Experts question study linking long COVID to deaths

Experts have expressed caution over new UK research indicating close to one in eight COVID patients had died in the months after being discharged from hospital.
 
The new retrospective cohort preprint of almost 48,000 patients hospitalised with COVID between January and September 2020 also shows almost 30% were readmitted to hospital within five months of being discharged, at a rate 3.5 times greater than other outpatients.
 
This, the study suggests, is down to ‘elevated rates of multi-organ dysfunction’, with older people and minority groups hit harder. The mean age of the cohort was 64.5 years, with 54.9% male.
 
But, the causal link is by no means certain, according to Melbourne respiratory physician Dr Alastair Miller, given the cohort’s advanced mean age, and the fact that death rates amongst older people who have been hospitalised can be high regardless.
 
Respiratory disease was also diagnosed in almost 30% of the patients after discharge, with around 40% of those having no prior history. Diabetes and major adverse cardiovascular events were particularly common amongst the post-discharge medical issues.
 
‘The long-term burden of COVID-related morbidity on hospitals and broader healthcare systems is likely to be substantial,’ the authors wrote.
 
‘Our findings across organ systems suggest that the diagnosis, treatment and prevention of PCS [post-COVID syndrome] will require integrated rather than organ- or disease-specific approaches.’
 
The UK study comes after a recent Lancet paper found 75% of discharged COVID patients still had at least one lingering health problem six months later, in a cohort study of 1700 people from Wuhan, where the virus first took hold.
 
Fatigue and muscle weakness were the most common, followed by sleep disturbance, and anxiety and depression. Around 200 had ground-glass opacity in the lungs, resulting in shortness of breath.
 
But Dr Miller, who is the clinical lead for the Royal Melbourne Hospital (RMH) virtual COVID ward, called for caution and patience in interpreting these results.
 
‘I certainly wouldn’t be using this data to talk about the mortality of long COVID. We need to be really careful drawing conclusions from preprint publications,’ he told newsGP.
 
‘We know that people who have been in hospital are more likely to be readmitted and more likely to die. I don’t see they’ve provided a control group to adequately control for that. 
 
‘If you had an elderly population admitted to hospital, it wouldn’t be too surprising if one in eight died in the following six months. So it’s good that it raises questions, but I just don’t think enough information is out there at the moment.’
 
Dr Miller also said the study had pulled data from existing databases rather than following their own cohort, which reduced the ability to draw a detailed clinical picture.
 
But he stressed that long COVID was shaping up as a large problem, with around 20% of those infected experiencing symptoms beyond four weeks. He said the RMH has a ‘constant trickle’ of people with persistent symptoms post-COVID.
 
Meanwhile, UK lecturer in intensive care Dr Charlotte Summers told The Guardian that the research showed ‘death is not the only outcome that matters’.
 
‘This matters,’ she said. ‘Long COVID at this level of morbidity and new disease is absolutely as important as the number of people dying.’
 
Associate Professor Hassan Vally, a La Trobe University epidemiologist, told newsGP persistent symptoms had emerged as a problem almost from the beginning.
 
‘Right from the start we recognised that it was more than just a respiratory virus and that in a lot of people, symptoms were persisting,’ he said. ‘This is not a simple respiratory virus – many organ systems are involved.’
 
According to Associate Professor Vally, determining the course of long COVID – and treatment options – will require tracking people over many years.
 
‘We’re learning more every week as we follow people with long COVID,’ he said.
 
The new data emerging around long COVID suggest GPs need to follow up any of their patients who had COVID – even milder, non-hospitalised forms of the disease, according to cohealth GP and medical epidemiologist Dr Nicole Allard.
 
‘For me, this is most concerning for those who didn’t get any care for their COVID,’ she told newsGP.
 
‘They might have had low health literacy, might not know how to interpret their symptoms and might not be seeking care.’
 
Dr Allard was part of a pioneering long COVID pathway linking GPs and hospital clinicians to provide care for around 1600 of the more than 20,000 cases found during Melbourne’s difficult second wave.

Many coronavirus patients seen through the pathway were vulnerable international students who did not have Medicare and who were working in heavily exposed jobs such as in aged care, and an initial audit of 100 patients found 10% still have persistent symptoms.
 
‘They might have symptoms like fatigue or pain and not know how to attribute it to COVID,’ she said. ‘Those who had COVID should be followed up post-illness.’
 
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COVID-19 long COVID morbidity