The Relationship between Particulate Matter (PM₁₀) and Hospitalizations and Mortality Of Chronic Obstructive Pulmonary Disease: A Meta-Analysis

Abstract

Background: Numerous studies have reported variable associations between ambient particulate matter (PM) and chronic obstructive pulmonary disease (COPD) hospitalizations and mortality. Objective: To conduct a systematic study assessing the associations between hospitalizations and mortality from COPD and ambient PM₁₀ (particulate matter with aerodynamic diameters ≤ 10 μm, PM₁₀). Methods: Systematic searches were conducted in 6 common electronic databases. A meta-analysis was performed to estimate the odds ratio (OR) to evaluate the relationship between PM₁₀ and COPD hospitalizations and mortality. Publication bias and heterogeneity of samples were tested by Begg funnel plot and Egger test, respectively. Study findings were analyzed using random-effect model and fixed-effect model. Results: The search yielded 31 studies suitable for the meta-analysis during the period from Jan 1, 2000 to Oct 31, 2011. A 10μg/m³ increase in PM₁₀ was associated with a 2.7% (95%CI = 1.9%-3.6%) increase in COPD hospitalizations with an OR of 1.027 (95%CI: 1.019–1.036), and a 1.1% (95%CI: 0.8%–1.4%) increase in COPD mortality with an OR of 1.011 (95%CI: 1.008–1.014). Conclusions: Ambient PM₁₀ is associated with increased COPD hospitalizations and mortality. Further research is needed to elucidate whether this association is causal and to clarify its mechanisms.

Keywords :

• Particulate matter
• COPD
• hospitalizations
• mortality
• meta-analysis

Acknowledgements

The authors thank Li-Ming Niu for providing statistical advice during the preparation of this manuscript and professor Si-Yan Zhan for epidemiologic questions. This work was supported by Grants from the National Natural Science Foundation of China [No.81072267 and 81170012].