The ongoing coronavirus disease 2019 (COVID-19) pandemic, caused by the rapid outbreak of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has claimed more than 6.52 million lives worldwide. The emergence of SARS-CoV-2 variants due to genomic mutations has prolonged the pandemic. Some SARS-CoV-2 variants, such as the Omicron and Delta, are more transmissible and virulent than the ancestral strain.

Background

Even though most COVID-19 patients recover from acute infection, some experience prolonged health conditions associated with cognitive, physical, and psychological issues, substantially affecting their quality of life. Hence, conducting regular follow-ups of COVID-19 patients discharged from hospitals is important. These studies will help understand the trajectory of symptom burden as well as long-term health outcomes associated with SARS-CoV-2 infection.

Previous research revealed that COVID-19 patients who required intensive care unit (ICU) treatment continued to experience physical, mental, or cognitive symptoms even after a year of being discharged from the hospital. Understanding the duration of persistence of COVID-19–related symptoms is imperative. 

A recent JAMA Network Open study assessed the dynamic trajectory of COVID-19 symptom burden as well as symptom persistence in those who survived SARS-CoV-2 infection for two years after being discharged from hospitals.

About the study

In this longitudinal cohort study, scientists collected data on COVID-19 survivors who were released from the Taikang Tongji and Huoshenshan hospitals. Both hospitals are located in Wuhan, China.

All participants were interviewed via telephone after the first and second years of their hospital release. The second-year follow-up study was conducted between March 1, 2022, and April 6, 2022. 

Apart from the telephonic interview, all participants also provided a self-reported symptom questionnaire along with a chronic obstructive pulmonary disease (COPD) assessment test (CAT). The symptoms of the participants were recorded as no problems, mild problems, moderate problems, or severe problems. Patients having at least one persistent COVID-19 symptom represented long COVID. 

Study findings

A total of 370 patients, i.e., 19.8% of the study cohort, were found to experience COVID-19 symptoms after two years of their discharge from the hospital. 12.0% of the study cohort reported persistent symptoms, while 7.8% of patients experienced new-onset or worsening symptoms from a reported level of mild symptoms at the first-year follow-up.

Some common symptoms the participants experienced were chest tightness, fatigue, dyspnea, myalgia, and anxiety. The majority of the symptoms disappeared over time. Even though dyspnea persisted for longer, it reduced after one year. The finding of this study was in line with previous studies that revealed a decreasing trend in symptoms over time.

In this study, a higher risk of symptom persistence was linked with ICU admission. Additionally, COVID-19 infection in patients with cerebrovascular diseases was associated with the manifestation of the onset of new symptoms. 6.2% of participants exhibited CAT scores of at least 10. The current study observed a higher risk of symptom persistence in recovered COVID-19 patients who needed ICU care during their hospital stay or had chronic liver diseases. 

Chronic liver disease was identified as an important factor associated with the risk of symptom persistence. Additionally, a CAT score of 10 and higher also indicated a higher possibility of experiencing prolonged COVID-19 symptoms. 

Study limitations

The authors highlighted several limitations, including the absence of an age-matched and comorbidity-matched control group. Owing to this limitation, the patients’ long-term symptoms of the acute illness could not be determined. Another shortcoming of the current study was the loss of participants, especially older patients, during the follow-up. Age distribution is an important aspect because it is considered an effect modifier of post-COVID-19 symptoms. 

The current study also used a self-reporting symptom questionnaire instead of diagnostic tools, which enhances the risk of bias due to participants' subjectivity. The number of symptoms considered in this study was small, considering the fact that more than a hundred COVID-19-related symptoms have been reported. The emergence of SARS-CoV-2 variants has been endemic, which could have altered the virulence and long-term sequelae compared to the data analyzed in the present study.

Conclusions

The current longitudinal cohort study, which included COVID-19 survivors after two years of being released from hospitals, revealed the common symptoms that persisted for a prolonged period were fatigue, anxiety, chest tightness, dyspnea, and myalgia. Although most of these symptoms disappeared, dyspnea persisted at a reduced level over time. Severely infected COVID-19 patients who required ICU admission were at a higher risk of symptom persistence. This study provided insights into the dynamic trajectory of health outcomes of COVID-19 survivors.

Written by

Dr. Priyom Bose

Priyom holds a Ph.D. in Plant Biology and Biotechnology from the University of Madras, India. She is an active researcher and an experienced science writer. Priyom has also co-authored several original research articles that have been published in reputed peer-reviewed journals. She is also an avid reader and an amateur photographer.