Re: The effects of Air Pollution on asthma Hospital admissions in Adelaide, South Australia, 2003-2013: time series and case-crossover analysis.

We read with great interest the recent study by Chen K and colleagues [1] which showed an increase risk of asthma hospital admissions in all age groups with total pollen. However, there are numerous issues that have been overlooked in the analysis of the pollen variable. If these issues were considered, the authors may have observed stronger species-specific effects thereby contributing to the evidence base on which pollen species is the major trigger of asthma exacerbations requiring hospitalization. This article is protected by copyright. All rights reserved.