Volatile organic compounds in asthma diagnosis: a systematic review and meta-analysis.

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Volatile organic compounds in asthma diagnosis: a systematic review and meta-analysis.

Allergy. 2015 Oct 17;

Authors: Cavaleiro Rufo J, Madureira J, Oliveira Fernandes E, Moreira A

Abstract
We aimed to assess the value and classification rate of exhaled volatile organic compounds (VOCs) in asthma diagnosis. A PRISMA oriented systematic search for published studies regarding exhaled VOCs in asthma diagnosis was conducted based on pre-defined criteria. Studies presenting sensitivity and specificity values for the test were included in the meta-analysis. Pooled diagnosis odds ratios (DOR), area under the curve (AUC) and positive and negative likelihood ratios (LR) for exhaled VOC profiles were calculated; and publication bias, threshold effect and heterogeneity were estimated. Eighteen studies were selected for the qualitative analysis and 6 met the criteria for inclusion in the quantitative analysis. Mean (95%CI) pooled DOR, positive and negative LR were 49.3 (15.9 to 153.3), 5.86 (3.07 to 11.21) and 0.16 (0.10 to 0.26), respectively. The AUC value was 0.94. Only 3 of the 18 reviewed studies performed an external validation of the model using a different dataset. The results from the revised studies suggest that exhaled VOCs are promising biomarkers for asthma diagnosis and that several compounds, mainly alkanes, may be significantly associated with asthma inflammation. However, there are still various constraints associated with standardization and externally validated studies are needed to introduce exhaled VOCs profiling in a clinical scenario. This article is protected by copyright. All rights reserved.

PMID: 26476125 [PubMed – as supplied by publisher]

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Leukotriene-Receptor Antagonists Versus Placebo in the Treatment of Asthma in Adults and Adolescents: A Systematic Review and Meta-Analysis.

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Leukotriene-Receptor Antagonists Versus Placebo in the Treatment of Asthma in Adults and Adolescents: A Systematic Review and Meta-Analysis.

Ann Intern Med. 2015 Sep 22;

Authors: Miligkos M, Bannuru RR, Alkofide H, Kher SR, Schmid CH, Balk EM

Abstract
Background: Leukotriene-receptor antagonists (LTRAs) are recommended as an alternative treatment in patients with mild asthma, but their effect compared with placebo is unclear.
Purpose: To determine the benefits and harms of LTRAs as monotherapy or in combination with inhaled corticosteroids compared with placebo in adults and adolescents with asthma.
Data Sources: MEDLINE and the Cochrane Central Register of Controlled Trials from inception through June 2015.
Study Selection: Peer-reviewed, English-language, randomized, controlled trials in patients with asthma that reported the effect of LTRAs versus placebo on measures of asthma control.
Data Extraction: Three researchers extracted data on study population, interventions, outcome measures, and adverse events. One researcher assessed risk of bias.
Data Synthesis: Of the 2008 abstracts that were screened, 50 trials met eligibility criteria. Random-effects meta-analyses of 6 trials of LTRA monotherapy showed that LTRAs reduced the risk for an exacerbation (summary risk ratio [RR], 0.60 [95% CI, 0.44 to 0.81]). In 4 trials of LTRAs as add-on therapy to inhaled corticosteroids, the summary RR for exacerbation was 0.80 (CI, 0.60 to 1.07). Leukotriene-receptor antagonists either as monotherapy or add-on therapy to inhaled corticosteroids increased FEV1, whereas FEV1 percentage of predicted values was only improved in trials of LTRA monotherapy. Adverse event rates were similar in the intervention and comparator groups.
Limitation: Variation in definitions and reporting of outcomes, high risk of bias in some studies, heterogeneity of findings, possible selective outcome reporting bias, and inability to assess the effect of asthma severity on summary estimates.
Conclusion: Leukotriene-receptor antagonists as monotherapy improved asthma control compared with placebo, but which patients are most likely to respond to treatment with LTRAs remains unclear.
Primary Funding Source: National Institutes of Health.

PMID: 26390230 [PubMed – as supplied by publisher]

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Meta-analysis of the Association Between Secondhand Smoke Exposure and Physician-Diagnosed Childhood Asthma.

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Meta-analysis of the Association Between Secondhand Smoke Exposure and Physician-Diagnosed Childhood Asthma.

Nicotine Tob Res. 2013 Mar 28;

Authors: Tinuoye O, Pell JP, Mackay DF

Abstract
INTRODUCTION: Studies suggest an association between secondhand smoke exposure and the development of childhood asthma. Several countries are considering legislation to protect children from exposure. METHODS: A systematic review was conducted using MEDLINE, Embase, PubMed, and Web of Knowledge databases and a random effects meta-analysis was undertaken. Heterogeneity was assessed using the I(2) test. Publication and small study biases were examined visually using a funnel plot and tested formally using Egger test. Univariate and multivariate meta-regression analyses were undertaken, including a subgroup analysis of cohort studies to examine the effect of duration of follow-up. RESULTS: Twenty relevant studies were identified (14 cross-sectional, 4 cohort, and 2 case-control) and provided 31 estimates of effect size. The pooled odds ratio was 1.32 (95% CI: 1.23, 1.42, p < .001). There was moderate heterogeneity (I(2) = 74.2%, p < .001). On multivariate meta-regression analysis, effect size estimates were significantly higher for case-control studies (p = .042) and those using self-reported exposure to secondhand smoke (p = .050). There was no evidence of significant publication or small study bias (Egger test, p = .121). CONCLUSIONS: There is now consistent evidence of a modest association between secondhand smoke and physician-diagnosed childhood asthma. These results lend support to continued efforts to reduce childhood exposure to secondhand smoke.

PMID: 23539174 [PubMed – as supplied by publisher]

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