Dynamics of clinical manifestations and long-term respiratory outcomes in outpatients with COVID-19 of varying severity

The aim of this study was to conduct a comparative analysis of clinical manifestations of novel coronavirus infection (COVID-19) according to the degree of respiratory system involvement and to assess the frequency of persistent respiratory symptoms during long-term follow-up.

Material and Methods. A prospective cohort study included 177 individuals treated on an outpatient basis at the Amur Regional Healthcare Institution “City Polyclinic No. 4”, Blagoveshchensk, between 2020 and 2025. Three groups were formed: Group 1 – patients with mild viral pneumonia (CT-1, lung parenchyma involvement <25%) associated with COVID-19 (n=67); Group 2 – patients with confirmed SARS-CoV-2 infection and isolated upper respiratory tract involvement without radiological signs of pneumonia (n=60); control group – presumably healthy individuals (n=50). Data collection included symptom assessment, medical history, and physical examination within the first 72 hours of illness, with repeat monitoring after 2 weeks. At 3 and 12 months, patients completed a structured selfassessment questionnaire on post-COVID health status. Dyspnea was evaluated using the modified Medical Research Council (mMRC) scale. Statistical analysis was performed using Pearson’s χ² test and Fisher’s exact test (p <0.05).

Results. During the acute phase, patients in Group 1 experienced significantly higher rates of dyspnea (83.58% vs. 6.67%, p <0.001) and general weakness (100% vs. 86.67%, p <0.01) compared to Group 2. After 2 weeks, dyspnea persisted in 62.69% of Group 1 patients versus 6.67% in Group 2 (p <0.001). Group 2 (p >0.05); at 12 months, these figures were 26.87% and 25%, respectively. Conclusion. The extent of lung tissue involvement during the acute phase of COVID-19 determines the severity of clinical symptoms and the dynamics of respiratory impairments. A phenomenon of increasing dyspnea at 3 months was observed in patients without pneumonia, followed by regression by 12 months.

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