Table 1.

Post‐Covid syndrome in subjects aged 15–67 years

Study	Study design and sample size	Study location	Lasting symptoms/signs or diseases following Covid‐19 and occurrence (%)	Follow up after symptom onset or after hospital discharge	Main findings
Huang et al. 16	Longitudinal 1773	China	Fatigue or muscle weakness (63%), sleep difficulties, and anxiety or depression (26%) Lung diffusion impairment (up to 56% for severe Covid patients). In women, compared with men, was reported:	Median follow‐up time after symptom onset: 186.0 (175.0–199.0) days	Increasingly impaired pulmonary diffusion capacities and abnormal chest imaging manifestations were reported in patients with a more severe illness
			OR: 2.22 (95% CI: 1.24–3.98) for diffusion impairment
			OR: 1.80 (1.39–2.34) for anxiety or depression
			OR: 1.33 (1.05–1.67) for fatigue or muscle weakness
Goërtz et al. 17	Cross‐sectional 2159	Netherlands and Belgium	Fatigue (87%), dyspnea (71%), chest tightness (44%), headache (38%)	79 (SD ± 17) days after symptoms onset	The study excluded patients admitted to ICU. Number of symptoms during the infection was responsible for the largest unique contribution to post‐Covid syndrome (β = 0.58, p < 0.001).
Greenhalgh et al. 5	Case report 1	United Kingdom	Inability to exercise continued shortness of breath both motionless and when exerting, small waves of anxiety, considerable depression, continued loss of smell	12 weeks after hospital admission	Indications for specialist assessment including clinical concern along with respiratory, cardiac, and neurological symptoms that are new, persistent, or progressive
Zhao et al. 18	Retrospective multicenter cohort study 55	China	Gastrointestinal symptoms (30.91%), headache (18.18%), fatigue (16.36%), exertional dyspnea (14.55%) Residual abnormalities of pulmonary function (25.45%); diffusion reductions in DLCO (16.36%)	3 months after discharge	The level of d‐dimer was found an important prognostic factor for abnormal DLCO. Thus, for patients who have marked raised d‐dimer, pulmonary rehabilitation should need subsequently even in the absence of severe respiratory symptoms
Raahimi et al. 19	Case report 1	United Kingdom	Guillain–Barré syndrome	5 months after symptom onset	Hypothesis that it is the immune response to Covid‐19 and not the virus itself or the acute vascular changes that underly the pathophysiology of long Covid‐19 syndrome
Novak 20	Case report 1	United States	Orthostatic cerebral hypoperfusion syndrome (OCHOS)	>2 months after discharge	Indications for immunotherapy in patients with post‐Covid OCHOS
Walsh‐Messinger et al. 21	Case‐control 43 (21 post‐Covid patients vs. 22 Covid‐recovered patients)	United States	Impaired concentration was the most frequently reported symptom (48%), followed by headache (38%), rhinitis (20%), exercise intolerance, dyspnea, sleep impairment, brain fog, appetite loss, fatigue, and chest pain	From 28 to 291 days after symptoms onset	51% of participants were affected by post‐Covid syndrome; females were more vulnerable than males
Soh et al. 22	Case report 1	Japan	Posttraumatic stress disorder	46 days after ICU discharge	Indications for establishing a follow‐up system for the long‐term outcomes of patients after ICU discharge
Yu et al. 23	Retrospective 32	China	Pulmonary fibrosis (43.7%)	9 days after discharge	Fibrosis was more likely to develop in elderly patients with severe clinical conditions, especially in patients with high inflammatory indicators
You et al. 24	Follow up 18	China	Restrictive ventilatory defect (33.3% in severe cases), small function dysfunction (41.7% in nonsevere cases); pulmonary fibrosis (22.2%)	40 ± 11.6 days in cases with nonsevere illness, and 34.7 ± 16.5 days in cases with severe illness	In Covid‐19 survivors after discharge, restrictive ventilatory defect and small function dysfunction can be persistent, which are not associated with disease severity
Alhiyar et al. 25	Case report 1	Qatar	Pulmonary fibrosis	5 months after symptoms onset	Authors suggest doing a 6‐min walk test to assess exertional desaturation in patients who are fulfilling other discharge criteria for Covid‐19 pneumonia and acute respiratory distress syndrome
Tolba et al. 26	Cross‐sectional 287	Egypt	Fatigue (72.8%), anxiety (38%), joints pain (31.4%), continuous headache (28.9%), chest pain (28.9%), depression (28.6%), dyspnea (28.2%)	N/A	Severity of post‐Covid‐19 manifestations was related to the severity of Covid‐19
Puchner et al. 27	Cross‐sectional 23	Austria	Impairment of pulmonary function (87%) neuropsychological dysfunction (85%)	Mean = 24 days, SD 5 days after discharge	Post‐acute multidisciplinary rehabilitation led to significant clinical and functional improvements in individuals who suffered from severe or critical Covid‐19