title: [Does weather modify headaches? An empirical evaluation of bio-weather categorization].
abstract: BACKGROUND
  Headache patients frequently refer to the weather as a triggering factor for their headaches. Apart from a literature review, we tested empirically the generally used classification of weather epochs into a so called bio-weather categorization.
  
  
  METHODS
  Headache diary data (frequency, duration, intensity) of 98 patients in a headache trial were correlated with the concurrent bio-weather classification.
  
  
  RESULTS
  Correlations were small and significant only for the summer-half of the year (contingency coefficients between 0.04 and 0.06). The classification of certain types of weather as headache prone as used in the current bio-weather classification could only partly be verified.
  
  
  CONCLUSIONS
  There is a clear but small correlation between headache and weather. More, and more fine-grained, studies are warranted, especially for identifying those patients at risk for weather prone headaches. Clinically more important is the weather as a source of causal attributions.
authors.affiliation: Institut für Umweltmedizin und Krankenhaushygiene, Uniklinikum Freiburg, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Walach
authors.forename: A
authors.initials: A
authors.lastname: Schweickhardt
authors.forename: K
authors.initials: K
authors.lastname: Bucher
mesh_terms: D003627:Data Interpretation, Statistical; D006261:Headache / Q000209:etiology*; D006801:Humans; D008881:Migraine Disorders / Q000209:etiology; D012307:Risk Factors; D012621:Seasons; D013997:Time Factors; D014887:Weather