van der Wouden JC, Uijen JHJM, Bernsen RMD, Tasche MJA, de Jongste JC, Ducharme F. Inhaled sodium cromoglycate for asthma in children.
Cochrane Database Syst Rev 2008;
2008:CD002173. [PMID:
18843630 PMCID:
PMC8436730 DOI:
10.1002/14651858.cd002173.pub2]
[Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND
Sodium cromoglycate has been recommended as maintenance treatment for childhood asthma for many years. Its use has decreased since 1990, when inhaled corticosteroids became popular, but it is still used in many countries.
OBJECTIVES
To determine the efficacy of sodium cromoglycate compared to placebo in the prophylactic treatment of children with asthma.
SEARCH STRATEGY
We searched the Cochrane Airways Group Trials Register (October 2007), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2007), MEDLINE (January 1966 to November 2007), EMBASE (January 1985 to November 2007) and reference lists of articles. We also contacted the pharmaceutical company manufacturing sodium cromoglycate. In 2007 we updated the review.
SELECTION CRITERIA
All double-blind, placebo-controlled randomised trials, which addressed the effectiveness of inhaled sodium cromoglycate as maintenance therapy, studying children aged 0 up to 18 years with asthma.
DATA COLLECTION AND ANALYSIS
Two authors independently assessed trial quality and extracted data. We pooled study results.
MAIN RESULTS
Of 3500 titles retrieved from the literature, 24 papers reporting on 23 studies could be included in the review. The studies were published between 1970 and 1997 and together included 1026 participants. Most were cross-over studies. Few studies provided sufficient information to judge the concealment of allocation. Four studies provided results for the percentage of symptom-free days. Pooling the results did not reveal a statistically significant difference between sodium cromoglycate and placebo. For the other pooled outcomes, most of the symptom-related outcomes and bronchodilator use showed statistically significant results, but treatment effects were small. Considering the confidence intervals of the outcome measures, a clinically relevant effect of sodium cromoglycate cannot be excluded. The funnel plot showed an under-representation of small studies with negative results, suggesting publication bias.
AUTHORS' CONCLUSIONS
There is insufficient evidence to be sure about the efficacy of sodium cromoglycate over placebo. Publication bias is likely to have overestimated the beneficial effects of sodium cromoglycate as maintenance therapy in childhood asthma.
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