Inhaled disodium cromoglycate (DSCG) as maintenance therapy in children with asthma: a systematic review

Background-Disodium cromoglycate (DSCG) is included in the ETS guidelines o n the treatment of asthma for use in children, but is now used only infrequ ently. We have identified and interpreted the findings of all published ran domised, placebo controlled trials of DSCG in the prophylactic treatment of children with asthma. Methods-Several databases were searched to identify trials. Studies were in cluded if they investigated subjects with asthma aged 0-18 years old, addre ssed I maintenance treatment with inhaled DSCG, and were published in Engli sh. The methodological quality of the studies was assessed independently by three reviewers. The 95% confidence intervals (CI) of differences in the t reatment effect for cough and wheeze between placebo and treatment with DSC G were computed. The estimates were pooled and tested for homogeneity and, to assess possible publication bias, a funnel plot was made and tested for symmetry. Results-Of the 24 randomised, placebo controlled trials identified, the met hodological scores varied widely. The null hypothesis of homogeneity was re jected. Under the assumption of heterogeneity the overall CI for wheeze was 0.11 to 0.26 and for cough was 0.13 to 0.27. The overall tolerance interva ls (-0.11 to 0.48 and -0.04 to 0.43 for wheeze and cough, respectively) bot h included zero, so it cannot be concluded that future studies will show an effect of DSCG compared with placebo. Older studies were more often in fav our of DSCG. The funnel plots suggest publication bias; small studies with negative or equal outcomes are lacking. Conclusion-Given the apparent publication bias, the small overall treatment effect, and the tolerance interval including zero, there is insufficient e vidence that DSCG has a beneficial effect as maintenance treatment in child ren with asthma.