Background: Asthma-related outcomes are regularly used by studies to investigate the association between human exposure to landscape fire smoke and health. Robust summary effect estimates are required to inform health protection policy for fire smoke exposure.

Objective: To conduct a systematic review and meta-analysis to estimate the association between short-term exposure to landscape fire smoke (LFS) fine particulate matter (PM_2.5) and asthma-related outcomes.

Methods: We conducted a systematic review and meta-analysis following PRISMA guidelines. Four databases (PubMed, Medline, EMBASE and Scopus) and reference lists of recent fire smoke and health reviews were searched. The Newcastle-Ottawa Scale was used to evaluate the quality of case-crossover studies, and a previously validated quality assessment framework was used for observational studies lacking control groups. Publication bias was assessed using funnel plots and Egger's Test. The trim and fill method was used when there was evidence of publication bias. Sensitivity and influence analyses were conducted on all endpoints to test the robustness of estimates. Summary estimates were obtained for hospitalisations and emergency department (ED) visits. A descriptive analysis was conducted for physician visits, medication use, and salbutamol dispensations.

Results: From an initial 181 articles (after duplicate removal), 20 studies were included for quantitative assessment and descriptive synthesis. LFS PM_2.5 levels were positively associated with asthma hospitalisations (RR = 1.06, 95% CI: 1.02-1.09) and emergency department visits (RR = 1.07, 95% CI: 1.04-1.09). Subgroup analyses found that females were more susceptible than males for ED visits, and that there was an increasing association by age groups for hospital admissions and ED visits. High heterogeneity between studies was observed, but results were robust to sensitivity analysis.

Conclusions: Females and all adults aged over 65 years appear to be the population groups most sensitive to asthma-related outcomes when exposed to LFS PM_2.5. Overall, results were higher than those obtained for a typical PM_2.5 mixture.

Item Type:	Refereed Article
Keywords:	asthma emergency department visits, asthma hospitalisations, fine particulate matter, fires, meta-analysis
Research Division:	Environmental Sciences
Research Group:	Ecological applications
Research Field:	Ecosystem function
Objective Division:	Health
Objective Group:	Public health (excl. specific population health)
Objective Field:	Public health (excl. specific population health) not elsewhere classified
UTAS Author:	Borchers Arriagada, N (Mr Nicolas Borchers Arriagada)
UTAS Author:	Palmer, AJ (Professor Andrew Palmer)
UTAS Author:	Johnston, FH (Associate Professor Fay Johnston)
ID Code:	136565
Year Published:	2019
Web of Science® Times Cited:	17
Deposited By:	Menzies Institute for Medical Research
Deposited On:	2020-01-08
Last Modified:	2020-04-20
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