title: [Chronic obstructive pulmonary disease and the seasons of the year].
abstract: OBJECTIVE
  To study the existence of differences among patients with chronic obstructive pulmonary disease (COPD) hospitalized for exacerbation during different seasons of the year.
  
  
  METHODS
  
  
  
  METHODS
  transversal study.
  
  
  METHODS
  all patients admitted to the short-stay medical ward for exacerbation of COPD over a period of one year.
  
  
  METHODS
  demographic variables, disease history, signs and symptoms, baseline walking test, baseline function tests, baseline blood gases, length of stay and death while hospitalized.
  
  
  METHODS
  patient variables were described and the characteristics of autumn/winter admissions were compared to those of spring/summer admissions.
  
  
  RESULTS
  Two hundred thirty-two patients with a mean age of 70.9 +/- 9.4 years (87.9% male). Eighty-four (36.2%) were admitted in winter, 65 (28%) in spring, 30 (12.9%) in summer and 53 (22.8%) in autumn. Twenty-one percent were being treated with corticoids, 27% were using domiciliary oxygen therapy and 36% had cor pulmonale. Baseline lung function test results were as follows: FEV1 44%, FEV1/FVC 48%, pO2 65.9 mmHg and pCO2 43.5 mmHg. Mean length of stay was 4.9 +/- 6 days; 9 patients (3.9%) died. Only PCO2 upon admission showed seasonal autumn-winter versus spring-summer differences (44.3 versus 49.5, p = 0.0008). Statistically significant differences were not observed for other variables.
  
  
  CONCLUSIONS
  Clear seasonal variation can be observed in the number of patients requiring admission due to COPD exacerbation, but we found no relevant seasonally-related differences in disease characteristics.
authors.affiliation: Unidad de Corta Estancia Médica (UCEM), Complexo Hospitalario Juan Canalejo, A Coruña.
authors.forename: F
authors.initials: F
authors.lastname: de la Iglesia Martínez
authors.forename: C
authors.initials: C
authors.lastname: Pellicer Vázquez
authors.forename: V
authors.initials: V
authors.lastname: Ramos Polledo
authors.forename: R
authors.initials: R
authors.lastname: Nicolás Miguel
authors.forename: S
authors.initials: S
authors.lastname: Pita Fernández
authors.forename: F
authors.initials: F
authors.lastname: Diz-Lois Martínez
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D011446:Prospective Studies; D012621:Seasons; D013030:Spain; D018709:Statistics, Nonparametric