Characterising patterns of COVID-19 and long COVID symptoms: Evidence from nine UK longitudinal studies

Abstract

Multiple studies across global populations have established the primary symptoms characterising COVID-19 (Coronavirus Disease 2019) and long COVID. However, as symptoms may also occur in the absence of COVID-19, a lack of appropriate controls has often meant that specificity of symptoms to acute COVID-19 or long COVID, and the extent and length of time for which they are elevated after COVID-19, could not be examined. We analysed individual symptom prevalences and characterised patterns of COVID-19 and long COVID symptoms across nine UK longitudinal studies, totalling over 42,000 participants. Conducting latent class analyses separately in three groups ('no COVID-19', 'COVID-19 in last 12 weeks', 'COVID-19 > 12 weeks ago'), the data did not support the presence of more than two distinct symptom patterns, representing high and low symptom burden, in each group. Comparing the high symptom burden classes between the 'COVID-19 in last 12 week,' and 'no COVID-19' groups we identified symptoms characteristic of acute COVID-19, including loss of taste and smell, fatigue, cough, shortness of breath and muscle pains or aches. Comparing the high symptom burden classes between the 'COVID-19 > 12 weeks ago' and 'no COVID-19' groups we identified symptoms characteristic of long COVID, including fatigue, shortness of breath, muscle pain or aches, difficulty concentrating and chest tightness. The identified symptom patterns among individuals with COVID-19 > 12 weeks ago were strongly associated with self-reported length of time unable to function as normal due to COVID-19 symptoms, suggesting that the symptom pattern identified corresponds to long COVID. Building the evidence base regarding typical long COVID symptoms will improve diagnosis of this condition and the ability to elicit underlying biological mechanisms, leading to better patient access to treatment and services.

Identification of post-COVID-19 condition phenotypes, and differences in health-related quality of life and healthcare use: a cluster analysis

“…The duration of PCC was slightly longer in the phenotype with a higher number of symptoms. This in line with the findings of the study by Bowyer et al (2023), where the cluster with a higher burden appeared to be more common in individuals who had a COVID-19 infection more than 12 weeks before the study. There was no difference in the hospital admission rates between the phenotypes.…”

“…In the phenotype with the highest number of symptoms, HRQoL was the poorest and healthcare use was the highest. This finding is consistent with the results of a study by Bowyer et al (2023) in which data from 9 longitudinal studies were used in a latent class analysis. Based on an extensive set of symptoms, they identified two patterns, one with a low prevalence of symptoms and the other with a higher prevalence of symptoms [27].…”

Long Covid symptoms and diagnosis in primary care: a cohort study using structured and unstructured data in The Health Improvement Network primary care database

“…The variety of clinical manifestations of Long Covid has led to the suggestion that there may be distinct subtypes of the disease, possibly with differing immunological mechanisms or other aspects of pathophysiology. 23 Our latent class analysis found that a two class model had the best fit with the data, consistent with longitudinal cohort analyses 24 and symptom tracker apps. 8 This is different from the results from Subramanian et al 5 who found that a 3 class model was preferable.…”

Natural course of health and well-being in non-hospitalised children and young people after testing for SARS-CoV-2: a prospective follow-up study over 12 months

“… 25 Furthermore, in a recent review of nine UK longitudinal studies in adults, totalling over 42,000 participants, the symptoms characteristic of long COVID were similar to the commonest symptoms we describe in CYP, including fatigue, shortness of breath and muscle pain or aches, but also difficulty concentrating and chest tightness. 26 …”