Two new studies conducted in the United Kingdom describe the prevalence, severity, and impact of long COVID. One of the studies found fatigue, tiredness, and shortness of breath were the most common persistent symptoms among UK healthcare workers (HCWs) and had a significant impact on their work and life. The other suggested that pain is the most prevalent and severe symptom among long-COVID patients and that demographic factors such as age and ethnicity play a role in symptom severity.
Long-COVID prevalence in HCWs
In the first study, published yesterday in the Journal of Infection, researchers from the UK Health Security Agency (UKHSA) and Public Health Scotland analyzed data collected through the SARS-CoV-2 Immunity and Reinfection Evaluation (SIREN) study, a large prospective cohort study of UK HCWs participating in frequent polymerase chain reaction (PCR) and antibody testing for SARS-CoV-2 since June 2020.
Because HCWs in the UK and elsewhere have been disproportionately affected by COVID-19, the researchers wanted to determine the prevalence of persistent symptoms in SIREN participants and the impact of those symptoms on work and life.
An electronic survey was sent to SIREN participants who had reported a SARS-CoV-2 infection by September 12, 2022. The survey provided a list of 35 symptoms and asked about the severity of the initial infection, number of infections, prevalence of and healthcare consultations for persistent symptoms (lasting more than 12 weeks), impact on work-related and daily activities, and days absent from work.
Of the 16,599 participants eligible to complete the survey, 6,677 responded and 5,053 (median age, 49 years; 84.3% female; 90.7% White) were included in the final analysis. The prevalence of persistent symptoms differed by infection episode but was highest for first infections (32.7%) compared with second (21.6%) and third infections (21.6%). The most frequently reported symptoms were fatigue and tiredness, shortness of breath, and difficulty concentrating.
A higher prevalence of persistent symptoms was reported during the wild-type variant period than in the other variant periods (52.9% wild-type vs 20.9% Omicron for any symptom reported), and in general, almost every reported persistent symptom became less prevalent from the wild-type to Delta to Omicron periods.
A substantial proportion of UK healthcare workers in our cohort experienced persistent symptoms following their initial SARS-CoV-2 infection, and this has impacted their life and work.
A higher prevalence of persistent symptoms was also found among those who were unvaccinated (38.1%) than among those who were vaccinated (22.0%). Multivariable analysis showed that participants were less likely to report persistent symptoms in infections occurring after vaccination compared with those with an infection before vaccination in the Alpha/Delta and Omicron periods (Alpha/Delta adjusted odds ratio [aOR], 0.66; 95% confidence interval [CI], 0.51 to 0.87; Omicron aOR, 0.07; 95% CI, 0.01 to 0.65).
Of the participants who reported persistent symptoms, 51.8% and 42.1% said those symptoms impacted their day-to-day and work-related activities "a little," respectively, and 24.0% and 14.4% reported that the impact was "a lot." When asked about work adjustments, 8.9% said they had reduced their working hours, and 13.9% reported changing their work pattern. The median number of days taken off from work due to persistent symptoms was 14.
"A substantial proportion of UK healthcare workers in our cohort experienced persistent symptoms following their initial SARS-CoV-2 infection, and this has impacted their life and work," the study authors wrote. "This persistence of ill-health following acute infection in a substantial proportion of healthcare staff infected with SARS-CoV-2 has implications for workforce planning, and occupational health teams in designing supportive return to work policies."
Pain the most prevalent self-reported symptom
In the second study, published yesterday in JRSM Open, researchers from University College London (UCL) analyzed self-reported symptoms from 1,008 people in England and Wales who had been referred to a National Health Service post-COVID clinic and had reported their symptoms on an app—the Living with COVID Recovery Digital Health Intervention—from November 30, 2020, to March 23, 2022.
Their aim was to identify the prevalence of self-reported symptoms and the relationship between demographic factors and symptom intensity, which app users ranked on a scale of 0 ("not at all intense") to 10 ("extremely intense").
Of the 1,008 participants, 77% reported symptoms multiple times, and 23% reported symptoms only once. A total of 1,604 unique symptoms were reported, which researchers grouped into 109 symptom categories. The most prevalent symptoms reported were pain (26.5% of all symptoms reported), neuropsychological issues (18.4%), fatigue (14.3%), and dyspnea (shortness of breath, 7.4%). The intensity of the symptoms increased by 3.3%, on average, each month since participants initially registered on the app.
Our study highlights pain as a predominant self-reported symptom in long Covid, but it also shows how demographic factors appear to play a significant role in symptom severity.
Multiple linear regression analysis revealed that age, sex, ethnicity, education, and deprivation level were significantly associated with symptom intensity. For example, participants aged 68 to 77 and 78 to 87 experienced higher symptom intensity (32.8% and 86% higher, respectively) than those aged 18 to 27, women reported 9.2% more intense symptoms than men, and non-White individuals reported 23.5% more intense symptoms than White individuals.
Higher education levels were associated with less symptom intensity than the least educated, and people in less deprived areas had less intense symptoms than those in the most deprived areas. But the number of symptoms did not vary by deprivation level.
The study authors say treatment for long COVID should focus on the most prevalent symptoms and that understanding the observed associations can inform healthcare policies and strategies aimed at minimizing the burden of long COVID, which they say will remain a "pressing concern" for as long as new SARS-CoV-2 variants continue to emerge.
"Our study highlights pain as a predominant self-reported symptom in long Covid, but it also shows how demographic factors appear to play a significant role in symptom severity," lead author David Sunkersing, PhD, MSc, of the UCL Institute of Health Informatics, said in a UCL press release. "Our findings can help shape targeted interventions and support strategies for those most at risk."
