Methods

Randomised, double‐blind, cross‐over trial that explored the use of metronidazole for controlling the smell from fungating wounds in patients with breast cancer, using a placebo for comparison.

Care setting and location: not clearly stated; however, the authors worked in hospitals in London, UK.

Participants

People with breast cancer, and a fungating wound which had a troublesome smell and was unlikely to respond to irradiation or chemotherapy. Six of the nine who were recruited to the trial participated and completed both arms of the study. Mean age and sex were not reported.

Interventions

Intervention: metronidazole 200 milligram tablets given orally three times daily (TDS) for 14 days; and placebo tablets TDS given orally for 14 days.

Participants acting as their own controls.

Outcomes

Smell scores and anaerobe culture results were reported.

Smell was graded 0 to 3 with 0 indicating the smell was 'absent', 1 being 'not offensive', 2 being 'offensive but tolerable' and 3 being 'offensive and intolerable'. Anaerobe culture results were reported as '‐', '+', '++' and '+++'.

Notes

Funding source was not stated.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

It was stated that "a randomised, double‐blind, cross‐over design" was used (p1232) but detail on how the random sequence was generated was not provided.

Allocation concealment (selection bias)

Unclear risk

No detail about sequence generation or allocation concealment was provided.

Blinding of participants and personnel (performance bias)
All outcomes

Low risk

The trial was described as double blind whereby both participants and personnel were blind to the intervention and control through the use of "identical tablets".

Blinding of outcome assessment (detection bias)
All outcomes

Low risk

It was stated that the participant, nurse and doctor independently assessed smell at each visit; "double‐blind" implied that participant and personnel were unaware of which treatment is being dispensed at any particular time.

Incomplete outcome data (attrition bias)
All outcomes

High risk

Original sample size was 9 but 3 participants were withdrawn; results are presented for 6 (2/3rds of the original sample). This is a small sample size that is likely to have impacted on the results.

Selective reporting (reporting bias)

Unclear risk

Trial registration was not available, and because the outcomes of interest were not clearly specified, only inferred, we assessed the risk of bias for selective reporting as unclear.

Other bias

Unclear risk

Limited information on participant characteristics (e.g. age) and study setting.