Effect of Orally Administered N-Acetylcysteine on Chronic Bronchitis: A Meta-analysis
The effect of N-acetylcysteine (NAC) treatment for patients with chronic bronchitis (CB) is controversial. To better understand the role of NAC in CB treatment, we performed a meta-analysis to provide a more accurate estimation of the importance of NAC treatment.
PubMed, Embase, and CNKI were systematically searched. The pooled relative risk (RR) and 95% confidence intervals (CI) were calculated using either fixed-effect model or random-effect model based on heterogeneity examination. Statistical analyses were performed using the STATA 12.0 and RevMan 5.2.
A total of 11 publications with 775 patients who were taking NAC and 789 controls who were taking placebo were judged eligible regarding inclusion criteria. The pooled analysis demonstrated significant evidence that NAC reduced the frequency of CB exacerbations (RR = 0.81, 95% CI 0.69–0.93, P = 0.004). Patients treated with NAC had significant symptom improvement compared with controls (RR = 1.68, 95% CI 1.13–2.52, P = 0.01). NAC did not significantly increase the risk of adverse effects compared with placebo (RR 0.86, 95% CI 0.67–1.09, P = 0.22). Subgroup analysis was carried out to assess the stability of results. No publication bias was detected during analyses.
There is a role for NAC treatment in the management of CB by reducing symptoms and exacerbations compared with placebo, without increasing the risk of adverse effects. A regular treatment of low dosage (< 1200 mg per day) and a duration of at least 3 months seems to be effective.
KeywordsChronic bronchitis N-Acetylcysteine Meta-analysis
We are grateful to the authors of the primary studies included in this meta-analysis and thank Jun-fei Hu for his review and valuable feedback of the manuscript.
Sponsorship for this study and article processing charges were funded by projects in the Science and Technology Pillar Program from the Department of Science and Technology of Sichuan province (2015SZ0111). All authors had full access to all of the data in this study and take complete responsibility for the integrity of the data and accuracy of the data analysis.
All named authors meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship for this article, take responsibility for the integrity of the work as a whole, and have given their approval for this version to be published.
Jia Wei and Hao Yan initiated and coordinated the study. Cai-shuang Pang and Juan Han were responsible for the data collection and data analysis. Studies were reviewed by Hao Yan. Jia Wei wrote the first draft of the manuscript. All the authors were involved in the interpretation of the analyses and gave input to the final manuscript.
Jia Wei, Cai-shuang Pang, Juan Han, and Hao Yan have nothing to disclosure.
Compliance with Ethics Guidelines
This article is based on previously conducted studies and does not contain any studies with human participants or animals performed by any of the authors.
All data generated or analyzed during our study are included in this published article/as supplementary information files.
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