More than a third of Covid-19 patients had at least one lingering symptom of the illness within 3 and 6 months after infection in an analysis of the electronic health records of over 275,000 people by researchers from the University of Oxford.
Shortness of breath and other breathing problems, anxiety, and fatigue were among the most commonly reported long-Covid symptoms among the cohort recovering from Covid-19.
Older people and men at any age reported more breathing issues, while younger people and women reported more anxiety, depression, abdominal pain and diarrhea and headaches.
In all, 37% of people with confirmed Covid-19 included in the analysis reported at least one Covid-19-related symptom 3 to 6 months after infection, and they were more likely to report lingering symptoms than patients who had influenza during the same period.
Findings from the study, which is among the first to compare lingering symptoms among patients with Covid-19 and influenza, were published online Sept. 28 in the journal PLOS Medicine.
The retrospective electronic health data analysis is also among the first to explore the relationship between age, sex or severity of infection and long-Covid.
The study included the health records of 81 million patients, including 273,618 survivors of Covid-19. The researchers calculated the occurrence of symptoms within 3 to 6 months after diagnosis and within 6 months of diagnosis.
The nine core symptoms included in the analysis were dyspnea and other breathing problems, fatigue/malaise, chest/throat pain, headache, abdominal pain and other abdominal symptoms, myalgia, other pain, cognitive symptoms, and anxiety/depression.
Kaplin-Meier analysis and Cox proportional hazard modeling was used to compare the frequency of these symptoms to those reported by patients with influenza during the same time period.
More than half (57%) of the patients recovering from Covid-19 had one or more of the 9 symptoms in the first 6 months of their diagnosis, and 36.55% had at least one symptom between 3 and 6 months after diagnosis.
The incidence of specific symptoms within 6 months and between 3 and 6 months, respectively, was:
- 22.82% and 15.49% for anxiety and depression.
- 18.71% and 7.94% for dyspnea and other abnormal breathing.
- 12.82% and 5.87% for fatigue/malaise.
- 12.60% and 5.71% for chest/throat pain.
- 8.67% and 4.63% for headache.
- 11.60% and 7.19% for other pain.
- 15.58% and 8.29% for abdominal symptoms.
- 3.24% and 1.54% for myalgia.
- 7.88% and 3.95% for cognitive symptoms.
All 9 symptom categories were reported more often by people who had experienced Covid-19 than among those who only had influenza during the same time period, with an overall excess incidence of 16.60% and hazard ratios between 1.44 and 2.04 for all (P<0.001).
Subgroup analysis revealed that the incidence of any long-Covid symptom varied from 46.42% among children, teens, and very young adults (≤22 years), to 61.05% in those over 65 years, 63.64% in those hospitalized, and 73.22% in those admitted to ICUs due to Covid-19.
“Females were significantly more likely to have headaches, abdominal symptoms, and anxiety/depression, whereas males were significantly more likely to have breathing difficulties and cognitive symptoms,” Taquet and colleagues reported.
“Younger patients were significantly more likely to have headaches, abdominal symptoms, and anxiety/depression, whereas older patients were more likely to have breathing difficulties, cognitive symptoms, pain, and fatigue. Only minor differences were observed between white and non-white patients.”
The findings add to the evidence that “Covid-19 appears to be associated with long-term effects that are common and diverse, with 57% of patients having at least one long-COVID feature recorded in the 180 days after infection and 37% having them in the 90 to 180 days after diagnosis, of whom 40% had not had one in the first 3 months,” Taquet et al. noted.
“These features are all more common after Covid-19 than after influenza,” they added. “The fact that most hazards were proportional between the 2 cohorts or that the hazard ratios remained above 1 after 180 days indicates that the risk of long-Covid features occurring, or co-occurring, continues to increase 180 days after the illness and that, for most of them, they follow the same trend as in the acute phase of the illness.”
They concluded that while the incidence of long-Covid is becoming less of a mystery, very little is known about the cause or mechanisms involved, nor the “predictors beyond the limited demographic and severity markers we measured.”
“Research aimed at these issues is required,” they wrote. “For example, to what extent do preexisting health conditions or characteristics, or specific features of the acute infection, impact on long-Covid?
“Finally, we note that almost 43% of patients after influenza had at least one long-Covid feature recorded, including 29.7% during the 90- to 180-day period,” they continued. “In this regard, we suggest researchers take a broad and balanced view as to the nature and specificity of long-Covid. In the meantime, clinical services need to be prepared and resourced to enable management of long-Covid features according to the best available evidence as it emerges.”
-
More than half (57%) of the patients recovering from Covid-19 had one or more of the 9 symptoms in the first 6 months of their diagnosis, and 36.55% had at least one symptom between 3 and 6 months after diagnosis.
-
Older people and males reported more breathing issues, while younger people and females reported more anxiety, depression, abdominal pain and diarrhea, and headaches.
Salynn Boyles, Contributing Writer, BreakingMED™
Funding for this research was provided by the National Institute for Health Research, the Oxford Health Biomedical Research Centre, the Wellcome Trust and others. The researchers reported no relevant disclosures related to this study.
Cat ID: 190
Topic ID: 79,190,730,933,190,926,192,927,151,928,195,929,925,934
