title: [Does clustering exist in non-traumatic epistaxis?].
abstract: OBJECTIVE
  Non traumatic epistaxis seems to be clustering in different periods. This paper tries to find out if there is any relationship between incidence of epistaxis and the year season, month, week, day, hour and/or lunar phase.
  
  
  METHODS
  We have retrospectively studied 754 episodes seen between May 2001 and April 2002 in our Hospital. The following parameters were registered in each patient: age, sex, number of episodes, season, month, week, day, hour and lunar phase.
  
  
  RESULTS
  Epistaxis represented 12.1% of the total otolaryngological emergencies. That means an incidence of 0.1% of non traumatic epistaxis which needed hospital specialized attention. We found statistical differences (p = 0.003) in the number of epistaxis per day and the different months (greater in june and november). No differences were found in the remaining periods studied.
  
  
  CONCLUSIONS
  This paper shows monthly clustering of epistaxis episodes.
authors.affiliation: Servicio de Otorrinolaringología, Hospital Universitario La Paz, Universidad Autónoma de Madrid. javioloriz@seorl.net
authors.forename: J
authors.initials: J
authors.lastname: Olóriz
authors.forename: M P
authors.initials: MP
authors.lastname: Prim
authors.forename: N
authors.initials: N
authors.lastname: Sastre
authors.forename: J
authors.initials: J
authors.lastname: Gracia
authors.forename: J I
authors.initials: JI
authors.lastname: de Diego
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D004844:Epistaxis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged