McCormick 2005.

Methods	Randomised ‐ yes, computer‐generated randomisation sequence Concealment of allocation ‐ unclear; method not described Double‐blind ‐ no, open‐label trial, investigators blinded, parents not blinded Intention‐to‐treat (ITT) ‐ yes Loss to follow‐up ‐ described Design ‐ parallel
Participants	N ‐ 223 children (N = 218 children included in analysis at day 12) Age ‐ between 6 months and 12 years Setting ‐ secondary care: paediatric clinic of University of Texas Medical Branch (USA) Inclusion criteria ‐ children were required to have (a) symptoms of ear infection; (b) otoscopic evidence of acute otitis media (AOM), including middle‐ear effusion; (c) non‐severe AOM Exclusion criteria ‐ co‐morbidity requiring antibiotic treatment, anatomic defect of ear or nasopharynx, allergy to study medication, immunologic deficiency, major medical condition and/or indwelling ventilation tube or draining otitis in the affected ear(s) Baseline characteristics ‐ balanced
Interventions	Tx ‐ immediate treatment with antibiotics: oral amoxicillin 90 mg/kg/day twice daily for 10 days; N = 112 (N = 110 included in analysis at day 12) C ‐ expectant observation: no immediate antibiotics; N = 111 (N = 108 included in analysis at day 12) Children in the control group with AOM failure or recurrence received oral amoxicillin 90 mg/kg/day; children in Tx group with AOM failure or recurrence received amoxicillin‐clavulanate (90 mg/kg/day of amoxicillin component) Use of additional medication ‐ all parents received saline nose drops and/or cerumen‐removal drops (if needed), ibuprofen and over‐the‐counter decongestant/antihistamine to be given as needed
Outcomes	Primary outcomes ‐ (a) parent satisfaction with AOM care; (b) resolution of AOM symptoms after treatment, including number of doses of symptom medication given; (c) AOM failure (days 0 to 12) or recurrence (days 13 to 30) defined as attending to the paediatrician clinic with acute ear symptoms, an abnormal tympanic membrane, or an AOM severity score higher than that at enrolment; (d) nasopharyngeal carriage of Streptococcus pneumoniae strains resistant to antibiotics Secondary outcomes ‐ (a) minor adverse events caused by medication (e.g. allergy, diarrhoea and candidal infection); (b) serious AOM‐related adverse events (e.g. invasive pneumococcal disease, mastoiditis, bacteraemia, meningitis, perforation of the tympanic membrane, hospitalisation and emergency ear surgery; (c) parent‐child quality of life measures related to AOM Parents were instructed to complete a symptom diary from day 1 to 10 and a satisfaction questionnaire on day 12 and day 30; routine follow‐up appointments for data collection were scheduled for day 12 and day 30. Patient‐initiated visits were scheduled on request by the parents for children who seemed to not be responding to treatment
Notes	Investigator‐blinded trial comparing immediate antibiotic prescribing versus expectant observation (no prescription provided)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomisation sequence
Allocation concealment (selection bias)	Unclear risk	Method not described
Other bias	Low risk	ITT analysis ‐ yes, baseline characteristics ‐ balanced
Blinding of participants and personnel (performance bias)	Unclear risk	Investigator‐blinded study, parents not blinded
Incomplete outcome data (attrition bias)	Low risk	Loss to follow‐up at day 12 ‐ treatment: N = 2 (2%) and expectant observation: N = 3 (3%)