A Cochrane review included 3 studies with a total of 268 subjects. Meta-analysis of these studies found a beneficial effect of using a desensitization protocol over a rechallenge protocol at six months of follow-up for preventing discontinuation of cotrimoxazole (number needed to treat (NNT) 7.14, 95% confidence interval (CI) 4.0-33.0), and for lower incidence of overall hypersensitivity (NNT 4.55, 95% CI 3.03-9.09). No severe hypersensitivity reactions occurred for either protocol in the three studies.
Comment: The quality of evidence is downgraded by study quality; inadequate allocation concealment and by imprecise results; few patients and wide confidence intervals.