Analysis of environmental risk factors for chronic obstructive pulmonary disease exacerbation: A case-crossover study (2004-2013)

Abstract

Purpose We aim to assess if air pollution levels and climatological factors are associated with hospital admissions for exacerbation of chronic obstructive pulmonary disease (COPD) in Spain from 2004 to 2013. Methods We conducted a retrospective study. Information on pollution level and climatological factors were obtained from the Spanish Meteorological Agency and hospitalizations from the Spanish hospital discharge database. A case-crossover design was used to identify factors associated with hospitalizations and in hospital mortality. Postal codes were used to assign climatic and pollutant factors to each patient. Results We detected 162,338 hospital admissions for COPD exacerbation. When seasonal effects were evaluated we observed that hospital admissions and mortality were more frequent in autumn and winter. In addition, we found significant associations of temperature, humidity, ozone (O 3 ), carbon monoxide (CO), particulate matter up to 10 μm in size (PM 10 ) and nitrogen dioxide (NO 2 ) with hospital admissions. Lower temperatures at admission with COPD exacerbation versus 1, 1.5, 2 and 3 weeks prior to hospital admission for COPD exacerbation, were associated with a higher probability of dying in the hospital. Other environmental factors that were related to in-hospital mortality were NO 2 , O 3 , PM 10 and CO. Conclusions Epidemiology of hospital admissions by COPD exacerbation was negatively affected by colder climatological factors (seasonality and absolute temperature) and short-term exposure to major air pollution (NO 2 , O 3 , CO and PM 10 ).

<p>Effects of Ambient Temperature on Acute Exacerbations of Chronic Obstructive Pulmonary Disease: Results from a Time-Series Analysis of 143318 Hospitalizations</p>

“…5 Another potential trigger for such exacerbations is short-term exposures to extreme temperature. 6 Extremes of temperature, both cold and hot, have also been associated with excess mortality and morbidity among patients suffering from COPD. 7 Previously reported works have demonstrated conflicting results on the correlation of ambient temperature and COPD hospitalization, emergency room visits, and outpatient clinic visits.…”

“…7 Previously reported works have demonstrated conflicting results on the correlation of ambient temperature and COPD hospitalization, emergency room visits, and outpatient clinic visits. 6,[8][9][10][11][12][13] Several published studies suggest that a decline in ambient temperature is linked with a higher susceptibility to COPD risk. 6,[8][9][10] Other researches have reported higher COPD risks during high temperature.…”

“…6,[8][9][10][11][12][13] Several published studies suggest that a decline in ambient temperature is linked with a higher susceptibility to COPD risk. 6,[8][9][10] Other researches have reported higher COPD risks during high temperature. [11][12][13] However, research conducted in Taiwan from 2000 to 2008 has reported a U-shaped association.…”

<p>Lifetime Occupational History, Respiratory Symptoms and Chronic Obstructive Pulmonary Disease: Results from a Population-Based Study</p>

“…Outdoor air pollution in studies elsewhere consistently showed greater likelihood of respiratory symptoms in both children and adults [24][25][26][27] and COPD. [8][9][10] We hypothesize, that the basic air pollution level in Almaty is so high, that a distance of 50 to 100 meters from a major road cannot play a role in worsening the symptoms. Despite known very high levels of air pollution in Almaty, including particulate matter, especially in winter, no scientific analysis of air pollution levels has been published to date.…”

“…Finally, ambient air pollution is often not regarded as an important confounder in the occupational studies, despite growing evidence that it is independently associated with greater risk of COPD. [8][9][10] Therefore, the aim of the current analysis was to ascertain the effect of lifelong occupational history, ambient air pollution, and biochemically verified smoking status with COPD in general population of one the largest cities in Central Asia, Almaty.…”