title: Pattern recognition in menstrual bleeding diaries by statistical cluster analysis.
abstract: BACKGROUND
  The aim of this paper is to empirically identify a treatment-independent statistical method to describe clinically relevant bleeding patterns by using bleeding diaries of clinical studies on various sex hormone containing drugs.
  
  
  METHODS
  We used the four cluster analysis methods single, average and complete linkage as well as the method of Ward for the pattern recognition in menstrual bleeding diaries. The optimal number of clusters was determined using the semi-partial R2, the cubic cluster criterion, the pseudo-F- and the pseudo-t2-statistic. Finally, the interpretability of the results from a gynecological point of view was assessed.
  
  
  RESULTS
  The method of Ward yielded distinct clusters of the bleeding diaries. The other methods successively chained the observations into one cluster. The optimal number of distinctive bleeding patterns was six. We found two desirable and four undesirable bleeding patterns. Cyclic and non cyclic bleeding patterns were well separated.
  
  
  CONCLUSIONS
  Using this cluster analysis with the method of Ward medications and devices having an impact on bleeding can be easily compared and categorized.
authors.affiliation: Global Clinical Statistics, Bayer Schering Pharma AG, Müllerstrasse 178, 13342 Berlin, Germany. christoph.gerlinger@bayerhealthcare.com
authors.forename: Christoph
authors.initials: C
authors.lastname: Gerlinger
authors.forename: Jens
authors.initials: J
authors.lastname: Wessel
authors.forename: Gerd
authors.initials: G
authors.lastname: Kallischnigg
authors.forename: Jan
authors.initials: J
authors.lastname: Endrikat
mesh_terms: D000293:Adolescent; D000328:Adult; D016000:Cluster Analysis; D005260:Female; D012739:Gonadal Steroid Hormones / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D008499:Medical Records; D008598:Menstruation / Q000187:drug effects* / Q000502:physiology*; D008796:Metrorrhagia / Q000139:chemically induced; D046709:Pattern Recognition, Physiological; D013997:Time Factors; D055815:Young Adult
chemical_list: D012739:Gonadal Steroid Hormones