title: Influence of weather conditions on the onset of primary spontaneous pneumothorax: positive association with decreased atmospheric pressure.
abstract: OBJECTIVE
  Primary spontaneous pneumothorax is believed to result from blebs, or from other abnormalities of the pleural surface. There is no consensus as to whether a change in weather conditions can precipitate spontaneous pneumothorax. The aim of the present study was to investigate the influence of weather conditions on the onset of primary spontaneous pneumothorax.
  
  
  METHODS
  The case histories of 1051 inpatients with primary spontaneous pneumothorax treated at Nissan Tamagawa Hospital between January 2006 and December 2011 were analyzed retrospectively. Data on weather conditions were collected daily throughout the 6-year period. The data were analyzed to determine differences in weather conditions between days on which primary spontaneous pneumothorax occurred and those on which it did not.
  
  
  RESULTS
  Primary spontaneous pneumothorax occurred on 819 (37.3%) of 2191 study days. On days before and the day of primary spontaneous pneumothorax onset, the difference in mean atmospheric pressure was 0.6 hPa lower than on days in which no primary spontaneous pneumothorax occurred. This difference was statistically significant (P = 0.015). There was no statistical difference in mean, maximum, and minimum temperature, hours of sunshine, amount of precipitation, and mean and minimum humidity between days with and those without primary spontaneous pneumothorax.
  
  
  CONCLUSIONS
  This largest study of the literature showed decreased atmospheric pressure might play an important role in the occurrence of primary spontaneous pneumothorax.
authors.affiliation: Pneumothorax Research Center and Division of Thoracic Surgery, Nissan Tamagawa Hospital, Tokyo, Japan. tknhosp@yahoo.co.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Haga
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kurihara
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kataoka
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ebana
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001274:Atmospheric Pressure; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011030:Pneumothorax / Q000209:etiology*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D014887:Weather; D055815:Young Adult