Symptoms may include fatigue, shortness of breath, difficulty concentrating, and many more, but the precise nature of the symptoms is not well understood.
About 2 million people in the UK currently have COVID for a long time, according to the latest data from the National Statistics Office.
In the UK, long COVID-19 is defined as “signs and symptoms that continue or develop after acute COVID-19”. This definition is further divided into people who show symptoms between four and 12 weeks after infection (symptomatic COVID-19 ongoing) and for 12 weeks or more (post-COVID syndrome).
Symptoms may include fatigue, shortness of breath, difficulty concentrating, and many more, but the precise nature of the symptoms is not well understood. There are also gaps in our knowledge regarding the frequency of long COVID, and whether there are particular factors that put people at increased risk of developing the disease.
All of this is due in part to the fact that the symptoms used to define long-term COVID often vary between studies, and these studies are usually based on relatively few people. Therefore, the results may not apply to the wider population.
In a new study published in the journal Nature Communications, my colleagues and I analyzed data from ten UK-based long-term studies, along with 1.1 million anonymous electronic health records from general English practices. Based on these data, we investigated whether the long COVID-19 load (as common as it is) differs according to demographic and health characteristics, such as age, sex, and existing medical conditions.
The studies were established before the pandemic and have tracked participants for many years. From these surveys, we used data from 6,907 people who stated that they had COVID-19. Comparing it with data from the electronic health records of people diagnosed with COVID allowed us to examine the frequency of long COVID in those who have seen their GP and those who have not.
We found that of the people who reported having COVID in the studies, the proportion who reported symptoms for more than 12 weeks ranged from 7.8% to 17%, while 1.2% and 4.8% reported “debilitating” symptoms.
In electronic health records, we found that only 0.4 percent of people with a diagnosis of COVID subsequently registered as a long-term COVID patient. This low proportion of GPs ’diagnoses may be in part because the long formal COVID record was only introduced for physicians in November 2020.
National central study COVID-19, author provided
The proportion of people who had symptoms for more than 12 weeks varied by age. There was also much variation depending on what definition each study used to capture long COVID. But overall, we found evidence to suggest that an increased risk of long-term COVID was associated with increasing age to 70 years.
The studies include participants of different ages, from an average age of 20 to 63 years. Using a strict definition of symptoms affecting daily function, we found that the proportion of people with symptoms for 12 weeks or more increased overall with increasing age, ranging from 1.2% for those with of 20 years and 4.8% for those of 63 years.
We also found that a number of other factors are associated with an increased risk of developing long-term COVID. For example, being a woman, poorer pre-pandemic mental health, and general health, obesity, and having asthma were also identified as risk factors in both long-term studies and electronic health records.
These findings are broadly consistent with other emerging evidence on long-term COVID. For example, a recent international review study concluded that women are 22% more likely than men to suffer from long-term COVID.
It will be important to understand why these links exist, which is outside the scope of our research. But identifying who may be at higher risk for long-term COVID is important, and as we continue to learn more, this could inform public health prevention and treatment strategies.
Ellen Thompson, Postdoctoral Research Fellow, Department of Twin Research and Genetic Epidemiology, School of Life Course & Population Sciences, King’s College London
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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