Data extraction
Two independent researchers (EB and NM) extracted data from eligible studies. A data collection sheet was used for data extraction. A third author (SGh) judged disagreement between EB and NM. Data from each study were including: author’s name, year of publication, county of study, study design, number of studied patients, age range of children, interval between COVID 19 and pulmonary function assessment, mean± standard deviation (SD) of spirometry parameters and frequency of respiratory symptoms.