Sharma 2006.
Methods | Parallel‐group, randomised controlled trial This study was carried out in a secondary care setting at a single centre in India |
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Participants | 21 participants with proven nickel allergy by patch testing No dropouts Inclusion criteria of the trial
Exclusion criteria of the trial
Study population
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Interventions |
Intervention • Low‐nickel diet and disulphiram 125 mg daily in the first 2 weeks and 250 mg daily in weeks 3 and 4 in 11 participants Control intervention • Normal diet and placebo tablet (lactose) for 4 weeks in 10 participants Participants were followed up for 2 to 12 weeks after end of treatment Duration Up to 16 weeks (4 weeks of active treatment, 2 to 12 weeks of follow‐up) |
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Outcomes |
Primary outcome of the trial
Other outcomes
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Notes | Two weeks after the start of a low‐nickel diet in the experimental group, disulphiram was started for a duration of 4 weeks. Participants in the control group were treated only with a placebo tablet during those 4 weeks. In addition, the low‐nickel diet was continued during follow‐up (i.e. 12 weeks after disulphiram was stopped) The secondary outcome ‐ reduction in severity, investigator‐rated ‐ was included, but the article did not provide reproducible data Study authors were contacted for additional information with regards to the risk of bias table Declarations of interest: none declared Funding: no funding Sample size rationale: not stated |
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Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Random sequence generation (selection bias) | Low risk | Quote: "all the 21 patients were randomly divided in 2 groups" Comment: no further details in the article. Personal communication with study authors clarified that they had used a lottery system |
Allocation concealment (selection bias) | Low risk | No details about how allocation was concealed from participants and clinicians. Personal communication clarified that this was done by a third person |
Blinding of participants and personnel (performance bias) All outcomes | High risk | Quote: "it was a comparative study and participants were not aware if they belonged to study group or control group (single blind trial)" Comment: participant blinding attempted with the use of placebo tablets (lactose tablets), although participants in the control group were allowed to continue with their normal diet, while the intervention group remained on the low‐nickel diet. Site personnel probably were not blinded |
Blinding of outcome assessment (detection bias) All outcomes | High risk | Quote: "it was a comparative study and participants were not aware if they belonged to study group or control group (single blind trial)" Comment: observers were not blinded |
Incomplete outcome data (attrition bias) All outcomes | Low risk | None of the participants dropped out, and all participants were included in the analyses (21 of 21 = 100%) |
Selective reporting (reporting bias) | Unclear risk | No trial registration found. In the Methods section, no clear description is given of the outcome parameters; in the Results section, outcomes are listed that are not described in the Materials section |
Other bias | Unclear risk | Baseline comparisons: no baseline comparisons Diagnostic certainty: yes The study was completed |