Measuring the Effects of Air Pollution among Persons with Severe Emphysema: The National Emphysema Treatment Trial (NETT)
type: CreativeWork
description: Background: Emphysema is a chronic obstructive pulmonary disease that affects approximately 5 million people in the US. For subjects with severe emphysema, few effective treatment options exist; however, the recent adoption of lung volume reduction surgery (LVRS) is considered as a promising alternative to traditional therapy. The National Emphysema Treatment Trial (NETT) was a randomized controlled trial designed to assess the efficacy of LVRS and medical therapy versus standard medical management among participants with severe emphysema. Results from the trial demonstrated less morbidity and mortality among participants receiving LVRS. We evaluated the effects of air pollution on the health of NETT participants. Methods: Data from the NETT study (1998-2003) included 1218 subjects, men and women ages 39-84. We also obtained data from the US Environmental Protection Agency Air Quality Systems database, which included daily values of fine particulate matter (PM2.5) and ozone. ZIP code specific exposures were spatially interpolated with the use of log-normal kriged models. This methodology was employed in order to assign exposures in areas with few nearby air pollution monitors. We investigated whether there was evidence of differential air pollution exposure by individual and area-level measures of socioeconomic status (SES). We assessed both the short- and long-term health effects of air pollution on the respiratory morbidity of NETT participants using mixed linear and Poisson models, which accounted for the daily (repeated) measures of air pollution data. In addition, we constructed survival models to investigate the impact of air pollutant exposures on post-LVRS mortality. Results: NETT participants experienced varying levels of exposure to ozone and PM2.5 and increasing cumulative pollutant exposures were associated with decreasing values of area-level SES. We found that PM2.5 and ozone significantly worsened respiratory function in these subjects. There also app…
abstract: Background: Emphysema is a chronic obstructive pulmonary disease that affects approximately 5 million people in the US. For subjects with severe emphysema, few effective treatment options exist; however, the recent adoption of lung volume reduction surgery (LVRS) is considered as a promising alternative to traditional therapy. The National Emphysema Treatment Trial (NETT) was a randomized controlled trial designed to assess the efficacy of LVRS and medical therapy versus standard medical management among participants with severe emphysema. Results from the trial demonstrated less morbidity and mortality among participants receiving LVRS. We evaluated the effects of air pollution on the health of NETT participants. Methods: Data from the NETT study (1998-2003) included 1218 subjects, men and women ages 39-84. We also obtained data from the US Environmental Protection Agency Air Quality Systems database, which included daily values of fine particulate matter (PM2.5) and ozone. ZIP code specific exposures were spatially interpolated with the use of log-normal kriged models. This methodology was employed in order to assign exposures in areas with few nearby air pollution monitors. We investigated whether there was evidence of differential air pollution exposure by individual and area-level measures of socioeconomic status (SES). We assessed both the short- and long-term health effects of air pollution on the respiratory morbidity of NETT participants using mixed linear and Poisson models, which accounted for the daily (repeated) measures of air pollution data. In addition, we constructed survival models to investigate the impact of air pollutant exposures on post-LVRS mortality. Results: NETT participants experienced varying levels of exposure to ozone and PM2.5 and increasing cumulative pollutant exposures were associated with decreasing values of area-level SES. We found that PM2.5 and ozone significantly worsened respiratory function in these subjects. There also app…
author: Kariisa, Mbabazi M.
language: English
keywords: Environmental Health, Epidemiology, emphysema, air pollution
date published: 2013-05-20
date modified: 2026-07-24T03:36:08Z
provider: OhioLINK
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The Ohio State University