Analysis of environmental risk factors for pulmonary embolism: A case-crossover study (2001–2013)

• The relationship between environmental factors and pulmonary embolism (PE) is little known.
• PE epidemiology is adversely influenced by colder climatological factors.
• PE epidemiology is also adversely influenced by higher concentrations of ambient air pollution.

BackgroundThe 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.MethodsWe 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.ResultsA 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 2 weeks and 3 weeks respectively were used as controls) were significant risk factors for hospital admissions with PE.ConclusionsPulmonary embolism epidemiology was adversely influenced by colder climatological factors (absolute temperature, and seasonality) and higher concentrations of ambient air pollution (NO2, O3).