title: Validity of self-reported endometriosis and endometriosis-related questions in a Swedish female twin cohort.
abstract: To examine the validity of self-reported endometriosis and to improve the reliability of questionnaires by including endometriosis-related questions.
  
  
  
  Analysis of survey questionnaire data.
  
  
  
  Cross-sectional study.
  
  
  
  Cohort of 26, 898 female twins aged 20-60 years at interview, who participated in either of two surveys (1998-2002 or 2005-2006).
  
  
  
  None.
  
  
  
  Endometriosis diagnosis in the Swedish National Inpatient Registry (IPR).
  
  
  
  The self-reported endometriosis diagnoses and endometriosis-related questions from a nationwide population-based twin registry were linked with the IPR. Fairly good agreement was found between the self-reported and IPR data on endometriosis. The receiver operating characteristics (ROC) curves showed fairly good predictive ability of self-reported endometriosis to have a confirmed endometriosis diagnosis in the IPR with an area under the curve (AUC) 0.79 (95% confidence interval [CI], 0.77-0.81). Further, the predictive ability increased to AUC 0.89 (95% CI, 0.88-0.90) when there was additional information about infertility and age.
  
  
  
  Our results indicate that self-reported data on endometriosis are moderately accurate and may be useful in studies when register data are not available.
authors: Department of Clinical Science and Education Södersjukhuset, Karolinska Institutet, Stockholm, Sweden. Electronic address: rama.saha@ki.se.
authors: Rama
authors: R
authors: Saha
authors: Department of Clinical Science and Education Södersjukhuset, Karolinska Institutet, Stockholm, Sweden.
authors: Lena
authors: L
authors: Marions
authors: Department of Clinical Science and Education Södersjukhuset, Karolinska Institutet, Stockholm, Sweden.
authors: Per
authors: P
authors: Tornvall
mesh_terms: D000328:Adult; D019540:Area Under Curve; D003430:Cross-Sectional Studies; D004200:Diseases in Twins / Q000175:diagnosis* / Q000453:epidemiology; D004715:Endometriosis / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012042:Registries; D015203:Reproducibility of Results; D057566:Self Report; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult
keywords: Endometriosis; in-patient register; questionnaire; self-report