title: Interobserver and intraobserver variability in the histological dating of the endometrium in fertile and infertile women.
abstract: OBJECTIVE
  To assess effects of biopsy timing and fertility status on inter- and intraobserver variability in dating of the endometrium.
  
  
  METHODS
  Endometrial biopsy slides randomly selected from a multicenter study testing the utility of biopsy in the diagnosis of infertility were distributed to three gynecologic pathologists, who estimated cycle day using standard criteria. Readers were blinded to the purpose of the study, patient age, fertility status, or timing of biopsy relative to LH surge or next menses.
  
  
  METHODS
  Multicenter academic research programs in reproductive medicine.
  
  
  METHODS
  Eighty-two women with proven fertility, 83 infertile patients.
  
  
  METHODS
  Endometrial biopsy during midluteal (days 21-22) or late (days 26-27) luteal phase.
  
  
  METHODS
  Intraclass correlation coefficient (ICC), kappa.
  
  
  RESULTS
  Overall agreement was excellent (ICC 0.88); addition of readings by local pathologists decreased ICC only slightly. In subgroup analyses, ICCs were lowest for infertile women during the midluteal phase (0.65 vs. 0.71 for fertile women in the midluteal phase, and 0.88-0.90 for both groups in the late luteal phase). Intraobserver reliability was excellent (0.9-0.99). Agreement for diagnoses of "out-of-phase" was only moderate, with kappa values between 0.4 and 0.6.
  
  
  CONCLUSIONS
  Observer variability in dating the endometrium was greatest in infertile women during the window of implantation.
authors.affiliation: Department of Obstetrics and Gynecology, Duke University Medical Center, Durham, North Carolina 27710, USA. myers008@mc.duke.edu
authors.forename: Evan R
authors.initials: ER
authors.lastname: Myers
authors.forename: Susan
authors.initials: S
authors.lastname: Silva
authors.forename: Kurt
authors.initials: K
authors.lastname: Barnhart
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Groben
authors.forename: Mary S
authors.initials: MS
authors.lastname: Richardson
authors.forename: Stanley J
authors.initials: SJ
authors.lastname: Robboy
authors.forename: Phyllis
authors.initials: P
authors.lastname: Leppert
authors.forename: Christos
authors.initials: C
authors.lastname: Coutifaris
mesh_terms: D000328:Adult; D001706:Biopsy; D004717:Endometrium / Q000473:pathology*; D005260:Female; D005298:Fertility; D006801:Humans; D007247:Infertility, Female / Q000473:pathology*; D008183:Luteal Phase; D015588:Observer Variation; D013997:Time Factors