title: Analysis of environmental risk factors for pulmonary embolism: A case-crossover study (2001-2013).
abstract: BACKGROUND
  The relationship between environmental factors and pulmonary embolism (PE) has received little attention. The aim of this study was to estimate the influence of climatological factors and air pollution levels on PE in Spain from 2001 to 2013.
  
  
  METHODS
  We carried out a retrospective study. Data were collected from the Minimum Basic Data Set (MBDS) and the State Meteorological Agency (AEMET) of Spain. A case-crossover analysis was applied to identify environmental risk factors related to hospitalizations and deaths. For each patient, climatic and pollutant factors were assigned using data from the meteorological station closest to his/her postal code.
  
  
  RESULTS
  A seasonal effect for PE hospital admission was observed, with more frequent admissions noted during Spain's colder seasons with peaks in autumn and winter. Lower temperatures as well as higher concentrations of NO2 and O3 at the time of admission (when 2weeks and 3weeks respectively were used as controls) were significant risk factors for hospital admissions with PE.
  
  
  CONCLUSIONS
  Pulmonary embolism epidemiology was adversely influenced by colder climatological factors (absolute temperature, and seasonality) and higher concentrations of ambient air pollution (NO2, O3).
authors.affiliation: Pneumology Department, Hospital General Universitario Gregorio Marañón, Universidad Complutense de Madrid, Madrid, Spain. Electronic address: javier.miguel@salud.madrid.org.
authors.forename: Javier
authors.initials: J
authors.lastname: de Miguel-Díez
authors.affiliation: Preventive Medicine and Public Health Teaching and Research Unit, Department of Health Sciences, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Jiménez-García
authors.affiliation: Preventive Medicine and Public Health Teaching and Research Unit, Department of Health Sciences, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: López de Andrés
authors.affiliation: Preventive Medicine and Public Health Teaching and Research Unit, Department of Health Sciences, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain.
authors.forename: Valentín
authors.initials: V
authors.lastname: Hernández-Barrera
authors.affiliation: Preventive Medicine and Public Health Teaching and Research Unit, Department of Health Sciences, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Carrasco-Garrido
authors.affiliation: Department of Internal Medicine, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Monreal
authors.affiliation: Respiratory Department, Ramón y Cajal Hospital, IRYCIS, Madrid, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Jiménez
authors.affiliation: Medical-Surgical Unit of Respiratory Diseases, University Hospital Virgen del Rocio, Seville, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Jara-Palomares
authors.affiliation: Preventive Medicine and Public Health Teaching and Research Unit, Department of Health Sciences, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Álvaro-Meca
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000397:Air Pollution / Q000009:adverse effects*; D003080:Cold Temperature / Q000009:adverse effects*; D018592:Cross-Over Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006760:Hospitalization; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009585:Nitrogen Dioxide / Q000032:analysis; D010126:Ozone / Q000032:analysis; D011655:Pulmonary Embolism / Q000401:mortality*; D012189:Retrospective Studies; D012307:Risk Factors; D012621:Seasons; D013030:Spain / Q000453:epidemiology
chemical_list: D010126:Ozone; D009585:Nitrogen Dioxide
keywords: Air pollution; Epidemiology; Pulmonary embolism; Seasons; Temperature