Long-Term COVID-19 Lung Impairment 6 Months Post Hospital Discharge

Doctor checking coronavirus patient chest x-ray film at ward hospital.
The SISCOVID clinical trial assessed patients’ functional and radiological pulmonary impairments 6 months after hospital discharge for severe and non-severe COVID-19.

A recent clinical trial found patients previously hospitalized for COVID-19 frequently presented with persistent dyspnea, lung function impairment, and persistent fibrotic-like pattern, with such occurrences most common in those who had recovered from severe disease 6 months prior. These were among study findings recently published in Respiratory Medicine and Research.

The SISCOVID clinical trial (ClinicalTrials.gov Identifier: NCT04505631) sought to assess functional and radiological impairment 6 months following hospital discharge for COVID-19, looking at associations between pulmonary sequelae and severity of the initial infection.

Study authors conducted a multicenter, observational cohort study in 12 nonacademic French hospitals that included 320 patients (mean age, 61 years; 35.9% female) of whom 205 had severe COVID-19 requiring intensive care, high flow nasal cannula, invasive mechanical ventilation, or noninvasive ventilation.

Outcomes found at 6 months post discharge included: persistent dyspnea in 54.1% of the entire cohort (mMRC score ≥1), with prevalence and severity of dyspnea comparable in patients who had severe and nonsevere COVID-19; a fibrotic-like pattern at CT-scan in 40% of the entire cohort that was significantly more prevalent in those with severe COVID-19 (P =.007); restrictive ventilatory pattern in 21.6% of all patients (total lung capacity <80% predicted); and severe impairment in gas diffusing capacity in 20.1% of patients (DLCO <60% predicted).

Among individuals studied with more severe disease, the investigators commonly found (1) reduced exercise capacity; (2) greater prevalence of desaturation (≥4%) with the 6-minute walk test; (3) greater prevalence of fibrotic-like pattern and restrictive ventilatory pattern.

In reviewing outcomes over time, researchers found improved functional and radiological outcomes between months 3 and 6. Moreover, by month 6, age was seen as an independent risk factor for the fibrotic-like pattern and severe DLCO impairment. Severe COVID-19 was also identified as an independent risk factor for the fibrotic-like pattern and for restrictive ventilatory pattern at month 6.

Researchers concluded that at month 6, “Patients hospitalized for COVID-19, especially those recovered from a severe form of COVID-19, frequently presented persistent dyspnea, lung function impairment, and persistent fibrotic-like pattern, confirming the need for long-term post-discharge follow-up in these patients and for further studies to better understand long-term COVID-19 lung impairment.”

Study limitations included the observational design and attrition bias, and the inability to rule out pre-existing lung disease or occult pulmonary embolism.


Calcaianu G, Degoul S, Michau B, et al. Mid-term pulmonary sequelae after hospitalization for COVID-19: The French SISCOVID cohort. Respir Med Res. Published online June 14, 2022. doi:10.1016/j.resmer.2022.100933