Weichenthal, S and Belisle, P and Lavigne, E and Villeneuve, PJ and Wheeler, A and Xu, X and Joseph, L, Estimating risk of emergency room visits for asthma from personal versus fixed site measurements of NO2, Environmental Research, 137 pp. 323-328. ISSN 0013-9351 (2015) [Refereed Article]
Copyright 2015 Published by Elsevier Inc. Licenced under Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) http://creativecommons.org/licenses/by-nc-nd/4.0/
METHODS: Paired personal and fixed-site NO2 data were available from an independent population (47 children and 48 adults) in Windsor between 2005 and 2006. We used linear regression to estimate the relationship and measurement error variance induced between fixed site and personal measurements of NO2, and through a series of simulations, evaluated the potential for a Bayesian model to adjust for this change in scale and measurement error. Finally, we re-analyzed data from the previous case-crossover study adjusting for the estimated change in slope and measurement error.
RESULTS: Correlations between paired NO2 measurements were weak (R(2)≤0.08) and slopes were far from unity (0.0029≤β≤0.30). Adjusting the previous case-crossover analysis suggested a much stronger association between personal NO2 (per 1ppb) (Odds Ratio (OR)=1.276, 95% Credible Interval (CrI): 1.034, 1.569) and emergency room visits for asthma among children relative to the fixed-site estimate (OR=1.024, 95% CrI 1.004-1.045).
CONCLUSIONS: Our findings suggest that risk estimates based on fixed-site NO2 concentrations may differ substantially from estimates based on personal exposures if the change in scale and/or measurement error is large. In practice, one must always keep the scale being used in mind when interpreting risk estimates and not assume that coefficients for ambient concentrations reflect risks at the personal level.
|Item Type:||Refereed Article|
|Keywords:||Exposure measurement error, Asthma, Case-crossover studies|
|Research Division:||Medical and Health Sciences|
|Research Group:||Public Health and Health Services|
|Research Field:||Environmental and Occupational Health and Safety|
|Objective Group:||Public Health (excl. Specific Population Health)|
|Objective Field:||Environmental Health|
|UTAS Author:||Wheeler, A (Dr Amanda Wheeler)|
|Web of Science® Times Cited:||5|
|Deposited By:||Menzies Institute for Medical Research|
|Downloads:||267 View Download Statistics|
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