Coronavirus patients who are not admitted to hospital have a low risk of serious long-term effects, but they could report more visits to a GP in the six months after infection, new research suggests.
According to the six-month study, people who tested positive for the virus and were not admitted to hospital had a slightly increased risk of needing medical treatment for blood clots and breathing difficulties, compared with those who had not been infected.
There was also a slightly increased risk of starting medications for breathing difficulties and migraines.
However, the risks of these factors at the individual level remained small, researchers say.
Experts assessed the risk of initiating medication and receiving a hospital diagnosis for a new condition by comparing individuals who tested positive for coronavirus with those who had a negative test during the first wave of the pandemic in Denmark.
Senior author, Professor Anton Pottegard from the University of Southern Denmark, said: “Until now, most research investigating long-term complications from Covid-19 has been focused on hospitalised patients.
“But the reality is that the majority of people with Covid-19 are not admitted to the hospital.
“Our study finds a very low risk of severe delayed effects from Covid-19 in people who didn’t require hospitalisation for the infection.
“However, our research provided evidence for some long-term effects that did not require hospitalisation or the use of new medicines, which we found reflected in higher use of primary healthcare services after infection.
“This highlights the need to ensure clinicians have the resources and support to manage any potential long-term conditions.”
Researchers used data from the Danish health registries on everyone who was tested for the virus between February 27 last year and May 31 last year.
The study followed up 8,983 people who tested positive but were not admitted to hospital, and 80,894 people who tested negative during the period from two weeks to six months after the test.
By comparing data from the two groups, they assessed the relative risk of starting new medications and of receiving a diagnosis of a new health condition during this time.
The analysis, published in The Lancet Infectious Diseases, took into account variables that could be associated with having a positive versus negative test and with the risk of a more severe course of Covid-19, such as obesity, cancer, and kidney disease.
Among those who tested positive, 31% had initiated new medication treatments during the follow up period.
A more detailed analysis found that compared with those with a negative test, those with a positive test were at an increased risk of initiating medications to widen the airways (1.8% compared with 1.5%), and medications to treat migraines (0.4% compared with 0.3%).
The researchers say observed differences were generally small.
The risks of receiving a hospital diagnosis for a new health condition during follow- up were similar in the two groups (around 26%).
Compared with individuals who tested negative, those who tested positive were also at an increased risk of receiving a first diagnosis of breathing difficulties (1.2% compared with 0.7%) and blood clots in the veins (0.2 % compared with 0.1%).
Researchers also found that people who tested positive visited their general practitioners about 20% (1.2 times) more often than those who tested negative, and visited outpatient clinics 10% (1.1 times) more often.
However, there was no difference in the visits to the emergency department or being admitted to hospital.
Commenting on the limitations of the study, co-author Stine Hasling Mogensen, from the Danish Medicines Agency, said: “Our analysis only captures specific symptoms leading to contact with hospitals, so it is likely that the study underestimates symptoms which do not require this level of care, like fatigue and breathing difficulties which are not severe enough for hospitalisation or require initiation of new medical treatment.
“Previous research has found a high level of these symptoms reported by patients, so the differences between patient reports and healthcare encounters could be important to investigate in regards to potential unmet healthcare needs and the need for new medications for treatment.”