Data extraction and quality assessment
For each included article, we extracted the number of CLP patients
treated, patients’ age and sex, type of clefts included, clinical
indications to adenoidectomy, type of clinical evaluation (for inclusion
and/or outcomes), type of outcome(s) studied, and outcome(s).
Selected studies were assessed for both quality and methodological bias
according to the National Heart, Lung, and Blood Institute Study Quality
Assessment Tools (NHI-SQAT)[14]. Articles were rated in duplicate by
two authors (XX and XX, blinded for review purposes) and disagreements
were resolved by consensus. Items were rated as good if they fulfilled
at least 80% of the items required by the NHI-SQAT, fair if they
fulfilled between 50% and 80% of the items, and poor if they fulfilled
less than 50% of the items, respectively.
Also, the level of evidence was scored according to the Oxford Centre
for Evidence-based Medicine (OCEBM) level of evidence guide[15].