Literature Search strategy and Study selection
Relevant databases including Medline, Web of sciences, Embase and Scopus
were searched comprehensively to assess literature up to 30 December
2022 in English language. The search terms were including “COVID-19 or
corona virus 2019” or “SARS-CoV-2” AND (”pulmonary function” OR
”pulmonary diseases” OR “lung problem”) AND ”children” and
”pediatrics”. They were used separately or/and in combinations to obtain
the eligible documents. The references of eligible articles were
searched manually to find additional relevant papers. This study was
conducted in adherence to the Preferred Reporting Items for Systematic
Reviews and Meta-Analysis (PRISMA) statement (10). The current study was
based on published articles. Therefore, consent form was not needed. Two
researchers (EB and NM) independently reviewed titles and abstracts of
all studies to identify relevant articles. Articles were including
according to following criteria: (1) English language, longitudinal or
cross-sectional studies evaluating the pulmonary function and clinical
symptoms of children after COVID 19 infection (2) spirometry parameters
have been measured (3) the study population were pediatrics. Case
reports, case series, letter to editors, unpublished reports,
duplications and laboratory studies were excluded. In duplicate
articles, the recent and more informative one was included. Included
articles were assessed using Newcastle-Ottawa Quality Assessment Scale
(NOS) for cohort and cross-sectional studies (11) if a study obtained
five stars it was considered as good quality.