van Hasselt 1997.

Study characteristics
Methods	Three‐arm, non‐blinded, parallel‐group RCT, with a 2‐week duration of treatment and 8‐week duration of follow‐up
Participants	Location: Malawi, rural (Nkota Kota District) Setting of recruitment and treatment: Nkota Kota District. Community setting. Conducted between 4 to 23 August 1997. Sample size: 96 Number randomised: 12 in ofloxacin; 38 in neomycin/polymyxin B; 46 in acetic acid/spirit group Number completed: 69 children (93 ears): 11 in ofloxacin ear drops, 30 in neomycin/polymyxin B and 28 in acetic acid/spirit group Participant (baseline) characteristics: Age: not reported, "children" Gender (F/M): not reported Main diagnosis: children with CSOM (no details of criteria) High‐risk population: no, but hygiene was noted as 'poor' Cleft palate (or other craniofacial malformation): not reported Down syndrome: not reported Indigenous groups (Australian Aboriginals/Greenland natives): not reported Immunocompromised: not reported Diagnosis method: Confirmation of perforated tympanic membrane: yes ("most perforations were medium or large") Presence of mucopurulent discharge: ("typically filled with mucoid pus and often flies. Granulation present in most cases") Duration of symptoms (discharge): not reported Other important effect modifiers: Alternative diagnosis of ear discharge: not reported Number who have previously had grommets inserted: not reported Number who have had previous ear surgery: not reported Number who had previous antibiotic treatment for CSOM: not reported Inclusion criteria: Children with CSOM (not defined) Exclusion criteria: Not reported
Interventions	Intervention A (n = 12): ofloxacin 0.3% (Exocin) ear drops, 3 drops/8 hours. Duration of treatment = 2 weeks. Intervention B (n = 38): neomycin 0.5%/polymixin B 0.1%, ear drops, 3 drops/8 hours. Duration of treatment = 2 weeks. Comparator group(n = 46): acetic acid 2% in spirit 25% and glycerine 30, ear drops, 3 drops/8 hours. Duration of treatment = 2 weeks In all groups the participants were asked to keep the affected ear uppermost for 10 minutes after instillation. Concurrent treatment: aural toileting: suction cleaning in all groups at the start of the trial and at the review appointments at 1 and 2 weeks after the start of the trial
Outcomes	Outcomes of interest in the review: Primary outcomes: Resolution of ear discharge or "dry ear" whether otoscopically confirmed or not, measured at between 1 week to 2 weeks, and after 4 weeks. Unclear if otoscopically confirmed. Secondary outcomes: Not reported
Funding sources	It is assumed the funding was from the Christian Blind Mission International
Declarations of interest	No information provided
Notes	Unit of randomisation: unclear if randomised by patient or by ear. Most likely by person. Methods for reporting outcomes of patients with bilateral disease: counting bilateral ears separately. All ears reported separately. Data come from an unpublished report. In the analysis 3/11 (27.27%), 10/30 (33%) and 11/28 (39%) of participants had bilateral disease in the ofloxacin, neomycin and antiseptic acid groups respectively. The costs of treatment were DM 10.00 for ofloxacin ear drop, DM 0.60 for neomycin/polymyxin B ear drop and DM 0.25 for acetic acid/spirit drops.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Comment: the original report states that this is a "pilot trial" with no reference to blinding or randomisation. This was mentioned as a "randomised" trial in a 2002 paper by the author. If randomisation was done, it is unclear whether the unit of randomisation was the child or the ears (most likely per person). There was no clear ratio of randomisation, with 46 in the acetic acid group, 38 in the neomycin/polymyxin group and 12 in the ofloxacin group and the cheapest intervention had the most participants.
Allocation concealment (selection bias)	Unclear risk	Comment: there is no mention of allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: no mention of blinding. The same treatment regimen was used for each treatment group but the treatments would have been difficult to blind due to the differences in smell between the drops.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: as above, there is no mention of blinding
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: high overall dropout rate (27/96 = 28%). Unequally distributed between the treatment groups: 18 (39%); 8 (21%) and 1 (8%) did not complete the trial in the acetic acid/spirit; neomycin/polymyxin B and ofloxacin groups respectively.
Selective reporting (reporting bias)	High risk	Quote: "The children of the present trial will be reviewed after 8 weeks. The results will be presented at the next PAFOS Conference (Pan‐African Federation of Otorhinolaryngological Societies) in Nairobi, 7‐10 June 1998." Comment: no information on the planned outcomes. The report suggested that the patients were followed up to 8 weeks, but the outcome results could not be found. There is no protocol available on the WHO clinical trial registry.