Table 1:

Validity assessment of included studies using the Newcastle–Ottawa Scale¹¹

Study	Design	Setting; representiveness	Patients selected using a priori criteria	Level of training and supervision in the technique	Adverse effects and outcomes sought and documented systematically
Botma et al. 20001	Prospective/consecutive	Hospital emergency department; truly representative	Yes	Procedure explained to parents, performed under supervision of attending doctor	Yes
Purohit et al. 200812	Prospective/consecutive	Hospital emergency and ear, nose and throat departments; truly representative	Yes	Procedure clearly explained to parent	No, but stated that there were no complications
Backlin 199513	Retrospective	Hospital emergency department; somewhat representative	No	Instructions given to caregiver	Not specified, but none documented
Wagner 200314	Retrospective	Hospital emergency department, referred to otologist; somewhat representative	No	Parents instructed in the technique	No, but none documented
Taylor et al. 201015	Retrospective	Hospital pediatric emergency department; somewhat representative	No	Trained triage nurse on duty explained manoeuvre to parents	Yes, but none documented
Alleemudder et al. 200716	Not specified	Hospital emergency department; somewhat representative	No	Clear explanation given to parent, assistant held child	Not specified, but none documented
Hore 199617	Case report	Home; selected patient	No	Father was doctor and followed Backlin’s description13	No, but none documented
Manca 199718	Case report	Home; selected patient	No	Mother was doctor experienced in technique	No, but none documented

Note: Items from the Newcastle–Ottawa scale not shown here include determining exposure (secure written records for all studies), length of follow-up sufficient for outcomes to occur (sufficient in all studies), assessment of outcome (unblinded, but objective for all studies) and adequacy of follow-up (complete for all studies).