Barton 2011.

Study characteristics
Methods	Randomised and double‐blind, parallel, placebo‐controlled, clinical trial during 4 weeks
Participants	Participants that had received neurotoxic chemotherapy and developed numbness, tingling or pain for at least 1 month. Pain intensity > 4/10 was required for inclusion. Participants could not be concurrently treated with any agent with suspected efficacy for neuropathy, such as anticonvulsants or tricyclic antidepressants.
Interventions	Participants were randomised to receive 1.31 g of a compounded gel containing 10 mg of baclofen, 40 mg of amitriptyline HCL, and 20 mg of ketamine versus an identical appearing placebo gel. The gel was applied 2 times/day during 4 weeks.
Outcomes	The primary end point for the study was the change in the sensory neuropathy subscale as measured by the European Organization for Research and Treatment of Cancer QLQ‐CIPN20 (CIPN‐20); profile of mood states, brief pain inventory, and the sensory neuropathy subsection of the NCI common terminology criteria. Side effect profile was also evaluated.
Notes	There were 5 participants who withdrew from the study before starting study medication. There were 26 participants in the baclofen arm and 27 in the placebo arm who did not provide primary endpoint data.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomization was done using dynamic allocation to balance marginal distributions of the stratification factors".
Allocation concealment (selection bias)	Low risk	"Drug assignments to individual patients were accessible only by the North Central Treatment Group randomization office, study pharmacists, and the study statisticians".
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"Participants were randomised to receive 1.31 g of a compounded gel containing 10 mg of baclofen, 40 mg of amitriptyline HCL, and 20 mg of ketamine versus an identical appearing placebo gel".
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Participants completed questionnaires at baseline and at 4 weeks. Participants rated the severity of these symptoms on a 0 to 10 scale, with 10 being the most severe. Adverse events were evaluated through the patient‐reported questions mentioned above as well as being graded through the NCI Common Terminology Criteria, version 3.0".
Incomplete outcome data (attrition bias)	Low risk	Dropouts are balanced across groups: "There were 26 participants in the baclofen arm and 27 in the placebo arm who did not provide primary endpoint data. In the baclofen arm, 11 refused due to experiencing an adverse event and 15 refused for nonspecified reasons. In the placebo arm, eight refused due to an adverse event, one patient died, and 18 refused for nonspecified reasons".
Selective reporting (reporting bias)	Unclear risk	"The study was registered according to current US federal regulations". The instruments for evaluation of the primary and secondary endpoints are valid and clinically relevant.
Other bias	Unclear risk	The study appears to be free of other sources of bias