title: Diagnostic performance of IOTA simple rules for adnexal masses classification: a comparison between two centers with different ovarian cancer prevalence.
abstract: OBJECTIVE
  The aim of this study was to compare the diagnostic performance of the IOTA simple rules for classifying adnexal masses when used in two centers with different ovarian cancer prevalence.
  
  
  METHODS
  A prospective study was performed between June 2012 and December 2013 at two different centers with different ovarian cancer prevalence. Center A had high ovarian malignancy prevalence and Center B had low malignancy rates. Eligible patients were all women diagnosed as having a persistent adnexal mass. Examiners had to analyze the masses according to IOTA simple rules (SR) providing a diagnosis of malignant, benign or inconclusive. Those cases classified as inconclusive were then examined by an expert examiner (the same examiner in center A, a different examiner in center B), who had to classify the mass as malignant, benign or uncertain according to his subjective impression (SI). Definitive histologic diagnosis from tumors removed surgically was used as gold standard. The diagnostic performance was assessed by calculating the sensitivity and specificity, positive and negative likelihood ratios, for SR and SR+SI assessments. McNemar test was used for comparing sensitivity and specificity.
  
  
  RESULTS
  During this period, 247 women were eligible for this study. The rate of inconclusive masses was 18.4% and 18.0% for centers A and B, respectively (p>0.05). Ovarian malignancy rate was significantly higher in center A as compared with center B (27.2% versus 11.3%), (p=0.001). When analyzing only cases classifiable by SR, sensitivity in center A was significantly higher (100% versus 84.6% p=0.001), but specificity was similar in both centers (93.9% and 95.8% respectively). When analyzing SR plus SI, sensitivity in center A was significantly higher (100% versus 86.7% p=0.001), but specificity was similar in both centers (89.9% and 88.8%, respectively).
  
  
  CONCLUSIONS
  The diagnostic performance in terms of sensitivity of IOTA rules is higher in a center with higher prevalence of ovarian malignancy.
authors.affiliation: Department of Obstetrics and Gynecology, Hospital Sant Joan de Déu, BCNatal, University of Barcelona, Barcelona, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Ruiz de Gauna
authors.affiliation: Department of Obstetrics and Gynecology, Hospital Sant Joan de Déu, BCNatal, University of Barcelona, Barcelona, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Rodriguez
authors.affiliation: Department of Obstetrics and Gynecology, Clínica Universidad de Navarra, University of Navarra, Pamplona, Spain.
authors.forename: Begoña
authors.initials: B
authors.lastname: Olartecoechea
authors.affiliation: Department of Obstetrics and Gynecology, Clínica Universidad de Navarra, University of Navarra, Pamplona, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Aubá
authors.affiliation: Department of Obstetrics and Gynecology, Clínica Universidad de Navarra, University of Navarra, Pamplona, Spain.
authors.forename: Matías
authors.initials: M
authors.lastname: Jurado
authors.affiliation: Department of Obstetrics and Gynecology, Hospital Sant Joan de Déu, BCNatal, University of Barcelona, Barcelona, Spain.
authors.forename: María Dolores
authors.initials: MD
authors.lastname: Gómez Roig
authors.affiliation: Department of Obstetrics and Gynecology, Clínica Universidad de Navarra, University of Navarra, Pamplona, Spain. Electronic address: jlalcazar@unav.es.
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Alcázar
mesh_terms: D000291:Adnexal Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D006786:Hospitals, Urban; D006801:Humans; D007390:International Agencies; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology; D010053:Ovary / Q000000981:diagnostic imaging*; D017410:Practice Guidelines as Topic; D015995:Prevalence; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013030:Spain / Q000453:epidemiology; D009626:Terminology as Topic; D014463:Ultrasonography; D055815:Young Adult
keywords: Adnexal mass; Ovarian cancer; Ultrasound