Up to 1 in 8 adult patients have long-lasting COVID symptoms: study

A new Dutch study has found that up to one in eight adults exposed to COVID-19 will develop long-term symptoms.

The study, published in the peer-reviewed journal The Lancet, looked at groups of adults diagnosed with COVID-19, as well as those who were not, and looked at whether they were developing new or worsening symptoms of the disease.

The authors say their study found that about one in eight, or 12.7 percent, of patients in the general population had long-term COVID-19 symptoms.

Judith Rosmalen, a professor of psychosomatic medicine at the University of Groningen and lead author of the study, said in a press release published on Thursday that including uninfected people in the research provides a more reliable estimate of how likely COVID is to last in the general population.

The Canadian government, citing the World Health Organization, says between 10 and 20 percent of people will develop long-term COVID.

The main symptoms of long COVID examined for the Dutch study were chest pain, difficulty or painful breathing, muscle pain, loss of taste and smell, tingling in the extremities, lump in the throat, hot and cold sensations, heavy arms or legs and general fatigue.

“There is an urgent need for data that informs the extent and scope of long-term symptoms experienced by some patients after contracting COVID-19,” Rosmalen said in the press release.

“However, most previous research on long COVID has not addressed the frequency of these symptoms in people who have not been diagnosed with COVID-19, or the symptoms of individual patients prior to diagnosis of COVID-19.”

Researchers first asked participants in the Lifelines COVID-19 cohort study to regularly fill out digital questionnaires on 23 symptoms commonly associated with long-term COVID.

Lifelines is an intergenerational study with more than 167,000 participants from the northern population of the Netherlands.

Questionnaires were sent 24 times to the same people between March 2020 and August 2021. The researchers say most of the data was collected before COVID-19 vaccines were introduced in the Netherlands.

Participants were considered COVID-positive if they had either a positive test or a medical diagnosis.

The average age of the participants was 53.7 years, 60.8 percent were female.

Of the 76,422 participants, 4,231 had COVID-19. This group was then matched with 8,462 uninfected people, taking into account gender, age and confirmation of a COVID-19 diagnosis in a questionnaire in the positive group.

The study found that 381 of 1,782 COVID-positive participants (21.4 percent) had ongoing symptoms, compared to 361 of 4,130 uninfected people (8.7 percent).

Taken together, these symptoms are due to COVID-19 in 12.7 percent of patients, the researchers say.

“The post-COVID-19 condition, also known as long COVID, is an urgent problem with an increasing human toll,” said study graduate student and first author Aranka Ballering.

“Understanding the core symptoms and prevalence of post-COVID-19 in the general population represents a major advance in our ability to design studies that can ultimately provide information on successful healthcare responses to the long-term symptoms of COVID-19.”

The authors say the study only included patients infected with earlier COVID-19 variants — not including Delta and Omicron.

The true prevalence of COVID-19 could also be underestimated as asymptomatic infections go undetected, the researchers said.

The study did not look at other long COVID symptoms that have since been identified as potentially relevant, such as: B. Brain fog, the researchers said.

Because the study only looked at the northern Netherlands, the authors say the results may not generalize to other areas.

Rosmalen says future research should also consider mental health symptoms like depression and anxiety, as well as those not included in the study, like brain fog, insomnia and post-exercise discomfort.