By Bhavana KunkalikarDec 29 2022Reviewed by Aimee Molineux

In a recent study published in Open Forum Infectious Diseases, researchers compared coronavirus disease 2019 (COVID-19)-specific long-term consequences to other viral respiratory infections.

Background

Since the beginning of the COVID-19 pandemic in 2020, an increasing number of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients have experienced persistent and long-lasting symptoms that linger for far longer than the typical duration of COVID-19 infection. A few symptoms, like fatigue, breathlessness, and brain fog, have been widely reported, but several other long-lasting repercussions of COVID-19 remain unexplored.

Several cardiovascular, gastrointestinal, neurological, musculoskeletal, immune-mediated, and metabolic symptoms may appear months following the SARS-CoV-2 infectious period, in addition to the probability of long-term respiratory consequences. Better knowledge of the long-term impact of COVID-19 is needed to inform public health.

About the study

In the present study, researchers investigated a diverse and large patient group to examine the health implications of SARS-CoV-2 infection that occur over a month after infection.

The team studied information obtained from healthcare facilities' electronic medical records collated in the Cerner Real-World Data dataset. Pharmacy, microbiological laboratory, hospitalization, and billing data from associated patient care facilities may be included in patient encounter information. All these data factors were time- and date-stamped to establish a temporal connection between clinical data and treatment patterns. The information is derived from electronic medical records created before 14 April 2022.

COVID-19 patients were identified with the help of the International Classification of Diseases, Tenth Revision, and Clinical Modification (ICD-10-CM) codes. The index encounters associated with non-COVID-19, and COVID-19 patients were extracted from medical encounters noted between 1 March 2020 and 1 April 2021. The index encounter connected to the viral respiratory infection (VRI) population was sampled from patients diagnosed with influenza, common cold, or viral pneumonia. It was described as the initial medical encounter related to each patient throughout the study period bearing either of the VRI ICD-10 codes. A third population, free of COVID-19 and VRI, was also recruited from the period assessed. This group's index encounter was described as a random event noted in the same timespan as the index encounters associated with the VRI and COVID-19 groups.

Propensity scores estimated using clinical and demographic factors were matched for patients belonging to the three groups to generate three independent matched groups for comparison: VRI versus COVID-19, COVID-19 versus non-infected, and non-infected versus VRI.

Results

Compared to the generic VRIs, COVID-19 at the time of index encounter proved to be a considerable predictor of diagnoses related to hair loss, palpitations, chest discomfort, dyspnea, obesity, and joint pain between approximately 30 and 365 days post-index encounter. In the comparisons between VRI and COVID-19 patients and control and COVID-19 patients, only dyspnea and chest discomfort was significantly increased. Pulmonary embolism, other respiratory failures, hypoxemia, oxygen dependence, and pneumonia were considerably more common in COVID-19 patients than in VRI patients but not in SARS-CoV-2-infected patients in comparison to control patients.

In this investigation, COVID-19 was not particularly correlated with any long-term neurological sequelae. Anosmia appeared significantly higher in COVID-19 and generic VRI patients, although there was no significant difference among the groups. Notably, the team found no considerable correlation between COVID-19 and depression/anxiety. Cognitive impairment was also higher in SARS-CoV-2-infected patients compared to VRI patients, although this correlation was not found in comparison to the control cohort.

COVID-19 was uniquely related to an elevated chance of being diagnosed with heart palpitations. In COVID-19 patients, tachycardia, heart failure, unspecified anemia, hyperlipidemia, and hypertension were more prevalent than in general VRI patients but not significantly higher compared to the control cohorts. Tiredness and joint discomfort were especially linked to initial COVID-19. More COVID-19 patients than VRI patients were diagnosed with type 1 diabetes, but no significant correlation was identified between COVID-19 patients and controls.

Conclusion

The study findings identified seven diagnoses corresponding to SARS-CoV-2 infection at the time of index encounter, which were significant predictors for diagnosis 30 to 365 days post-index encounter, compared to index encounters related to a general respiratory viral infection. The study also revealed that the period of symptoms varies between COVID-19 and common VRIs. The researchers believed that the study of the long-term effects on each type of infection vary over time giving potential for future research.