title: Phenotypes and body mass in women with polycystic ovary syndrome identified in referral versus unselected populations: systematic review and meta-analysis.
abstract: OBJECTIVE
  To compare the prevalence of polycystic ovary syndrome (PCOS) phenotypes and obesity among patients detected in referral versus unselected populations.
  
  
  METHODS
  Systematic review and meta-analysis.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Thirteen thousand seven hundred ninety-six reproductive-age patients with PCOS, as defined by the extended Rotterdam 2003 criteria.
  
  
  METHODS
  Review of PUBMED, EMBASE, and Cochrane Library, 2003-2016. Only observational studies were included. Data were extracted using a web-based, piloted form and combined for meta-analysis.
  
  
  METHODS
  PCOS phenotypes were classified as follows: phenotype A, clinical and/or biochemical hyperandrogenism (HA) + oligo-/anovulation (OA) + polycystic ovarian morphology (PCOM); phenotype B, HA+OA; phenotype C, HA+PCOM; and phenotype D, OA+PCOM.
  
  
  RESULTS
  Forty-one eligible studies, reporting on 43 populations, were identified. Pooled estimates of detected PCOS phenotype prevalence were consequently documented in referral versus unselected populations, as [1] phenotype A, 50% (95% confidence interval [CI], 46%-54%) versus 19% (95% CI, 13%-27%); [2] phenotype B, 13% (95% CI, 11%-17%) versus 25% (95% CI, 15%-37%); [3] phenotype C, 14% (95% CI, 12%-16%) versus 34% (95% CI, 25-46%); and [4] phenotype D, 17% (95% CI, 13%-22%) versus 19% (95% CI, 14%-25%). Differences between referral and unselected populations were statistically significant for phenotypes A, B, and C. Referral PCOS subjects had a greater mean body mass index (BMI) than local controls, a difference that was not apparent in unselected PCOS.
  
  
  CONCLUSIONS
  The prevalence of more complete phenotypes in PCOS and mean BMI were higher in subjects identified in referral versus unselected populations, suggesting the presence of significant referral bias.
authors.affiliation: Department of Obstetrics and Gynecology, Medical College of Georgia, Augusta University, Augusta, Georgia; Medical Company IDK, Samara, Russian Federation; Department of Reproductive Health Protection, Scientific Center of Family Health and Human Reproduction, Irkutsk, Russian Federation.
authors.forename: Daria
authors.initials: D
authors.lastname: Lizneva
authors.affiliation: Cochrane South Asia, BV Moses Center for Evidence-Informed Health Care and Health Policy, Christian Medical College, Vellore, India.
authors.forename: Richard
authors.initials: R
authors.lastname: Kirubakaran
authors.affiliation: Department of Obstetrics and Gynecology, Maimonides Medical Center, Brooklyn, New York.
authors.forename: Kateryna
authors.initials: K
authors.lastname: Mykhalchenko
authors.affiliation: Department of Reproductive Health Protection, Scientific Center of Family Health and Human Reproduction, Irkutsk, Russian Federation.
authors.forename: Larisa
authors.initials: L
authors.lastname: Suturina
authors.affiliation: Department of Gynecological Endocrinology, Scientific Center for Obstetrics, Gynecology and Perinatology, Moscow, Russian Federation.
authors.forename: Galina
authors.initials: G
authors.lastname: Chernukha
authors.affiliation: Department of Obstetrics and Gynecology, Medical College of Georgia, Augusta University, Augusta, Georgia.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Diamond
authors.affiliation: Department of Obstetrics and Gynecology, Medical College of Georgia, Augusta University, Augusta, Georgia; Department of Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia. Electronic address: razziz@augusta.edu.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Azziz
mesh_terms: D015992:Body Mass Index; D005260:Female; D006801:Humans; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D064887:Observational Studies as Topic; D010060:Ovulation; D010641:Phenotype; D011085:Polycystic Ovary Syndrome / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D015995:Prevalence; D012017:Referral and Consultation; D015983:Selection Bias
keywords: Polycystic ovary syndrome; epidemiology; meta-analysis; phenotypes; prevalence; referral bias