Long-COVID Symptoms Pose Challenges for Treatment

long covid
Study: Long Covid clinical severity types based on symptoms and functional disability

Researchers monitored people with long COVID (LC), defined as persisting symptoms after four weeks of a suspected or confirmed coronavirus disease 2019 (COVID-19) infection, throughout a longitudinal investigation in a study published in The Lancet. During the course of the trial, more than half of the patients shifted between clinical severity levels.


According to researchers, 1.9 million people in the UK and more than 200 million people globally have LC, although it is still poorly understood. LC is thought to influence ten organ systems and is connected with 200 symptoms such as shortness of breath, pain, exhaustion, dizziness, sleep problems, anxiety, depression, allergic reactions, skin rashes, and post-traumatic stress disorder. The most well-known symptom of LC is cognitive impairments, also known as “brain fog.”

In clinical research conducted in the United Kingdom, patients were requested to register their symptoms on the COVID-19 Yorkshire Rehabilitation Scale (C19-YRS) so that physicians could better understand how this condition affects them. Their overall health (OH), functional disability (FD), and symptom severity (SS) are all scored.

A study of hospitalized LC patients discovered that they had various degrees of impairment and reported having nine symptoms on average even five months after they were discharged. Another cross-sectional study discovered that some patients who were not hospitalized also had severe instances of LC. However, whether or not the severity of LC changed over time and whether or not there were relationships between the three domains of the C19-YRS.

About the Study

The current longitudinal study sought to investigate variations in clinical severity between two assessments and to describe the linear association between OH, FD, and SS. Participants with LC were included in the study, but a positive test result was not required because testing was not readily available at the start of the epidemic. Participants were undergoing LC therapy from approved LC services and exhibited symptoms that could not be explained by another diagnosis. Furthermore, all participants were registered on the same medical platform and were required to fill out updated C19-YRS forms every three months.

The updated C19-YRS form included 17 questions designed to assess LC symptoms and their influence on general health and everyday activities. Participants identified any other symptoms they had experienced in the previous week, in addition to the OH, FD, and SS domains. The researchers used Spearman correlations, heat maps, cluster analysis, and polychoric component analysis to examine the data, and Kendall’s kappa and tau to assess intra-patient agreement.

Key Findings

The initial round of assessments were completed by 759 patients, with females accounting for 69.4% of the total. However, 47%, or 356 people, finished the second round, with 68% of them being women. Participants completed the second assessment 16.2 days following the first. The majority of patients (74%) were Caucasian, with an average age of 46.8 years.

A little more than half had never smoked. More than half were on sick leave, had reduced their working hours, or had changed jobs because to LC. During the first assessment, the median participant had been experiencing symptoms for about a year.

In their study population, researchers found three separate categories of clinical severity: two with’mild’ severe’ dysfunction and symptomatology, and a third with moderate.’ The moderate group got high scores on average for symptoms such as weariness and post-exertional malaise (PEM), but low values for smell and cough, and moderate scores for other symptoms.

According to the intra-patient agreement analysis, 41% of participants had distinct types of FD and SS clusters in terms of severity. In the second assessment, slightly less than half of the patients were classified as SS or FD, indicating that many participants experienced a change in the severity of their symptoms. However, while OH remained steady for the majority of patients, about one-third exhibited OH alterations between evaluations. A single underlying component explained 41-45% of the variance in the SS subscale and 60-62% of the variance in the FD subscale, according to the polychoric factor analysis.


The findings of this study demonstrate how symptoms experienced by more than half of LC patients might change over time, which has important implications for healthcare interventions and self-management. The coexistence of diverse severity classes for the majority of symptoms suggests that LC is caused by shared underlying processes such as immunological activation, immune dysregulation, endothelium damage, viral persistence, and dysautonomia.

Mild, moderate, and severe LC conditions can help improve patient interventions. The authors recommend that mild cases be monitored through primary care services and that intermediate and severe cases be treated by specialists. Such therapies must take into account the dynamic and changeable nature of LC symptoms.

“Long COVID should be assessed and evaluated in the light of the fluctuant nature of the condition and not necessarily assumed always to have the same type or severity of the symptoms.”


For more information: Sivan, M., et al. Long Covid clinical severity types based on symptoms and functional disability: a longitudinal evaluation. The Lancet. https://dx.doi.org/10.2139/ssrn.4642650https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4642650

Rachel Paul is a Senior Medical Content Specialist. She has a Masters Degree in Pharmacy from Osmania University. She always has a keen interest in medical and health sciences. She expertly communicates and crafts latest informative and engaging medical and healthcare narratives with precision and clarity. She is proficient in researching, writing, editing, and proofreading medical content and blogs.

more recommended stories