142nd APHA Annual Meeting and Exposition

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Association between asthma hospitalizations and ozone level in Maricopa County from 2007 through 2012 using time-series analysis

142nd APHA Annual Meeting and Exposition (November 15 - November 19, 2014): http://www.apha.org/events-and-meetings/annual
Sunday, November 16, 2014

Ahmed Mohamed, BVSc, MSc, PhD , Department of Public Health, Maricpoa County, Phoenix, AZ
Ozone is and environmental pollutants that can have adverse health effects. However, evaluating these effects is not always a straightforward process because used methods should account for potential confounders including -for example- seasonality of data recorded over time and the fact that this effect may persist after the time of the exposure.  The objective of this study was to evaluate the association with ozone concentration from 2007 through 2012. The study data consisted of daily hospital discharge data (HDD) and hourly meteorological measurements obtained from MC’s Department of Public Health and Department of Air Quality.  A GIS program was used to geocode hospitalizations records and to assign them exposure recordings based on admission date and location. We used time plots and distributed-lag non-linear model (DLNM) to achieve these objectives while accounting for some potential confounders including temperature and day of the week.

 Results: A total of 90,381 asthma hospitalizations were retrieved from the dataset (daily median=39, range: 8-122). Asthma hospitalizations were highest in 2008 (16,949), from November through December, and lowest in 2011 (13213) and in June-July. By contrast, the average daily ozone concentration ranged from 27.05 in 2012 to 30.15 in 2008 and from 13.96 in December to 40.58 in May.  The association between asthma hospitalizations [relative risk (RR/per 10 unit increase of ozone)] start at ~ 1.025; 95%CI(1.006 – 1.046) at lag 0 and diminishes by lag 7.

Our findings suggest exposure to increased ozone level is associated with increased RR of asthma hospitalizations in Maricopa County that last for days after the exposure. This study used recently developed methods that are freely available and could be used to evaluate other health events that are measured over time.

Learning Areas:

Biostatistics, economics
Environmental health sciences

Learning Objectives:
Evaluate the association between asthma hospitalization and ozone level in Maricopa County using times-series analysis methods to account for the lagged effect and residual serial auto-correlation.

Keyword(s): Air Pollution & Respiratory Health, Environmental Health

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have a substantial experience conducting epidemiological study in analysis for various public health subjects using small and large datasets, including hospital data. My credentials and skills include advanced degrees and training in epidemiology including areas such as time-series, risk factors, and spatial-temporal analyses. I am also the lead or co-authors of several publications in some of the prominent peer-reviewed national and international journals including, Prev. Vet. Med, JAVMA, and Vet. Parasitol., among others.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.