title: Residual hormone levels in used contraceptive rings as a measurement of adherence to vaginal ring use.
abstract: OBJECTIVE
  This study sought to measure residual contraceptive hormone levels in vaginal rings as an adherence marker for monitoring product use in clinical trials.
  
  
  METHODS
  Residual etonogestrel and ethinyl estradiol levels from used NuvaRings® of 26 self-reported adherent women enrolled in a clinical trial of vaginal ring acceptability were compared to those from 16 women who used NuvaRing® as their contraceptive choice.
  
  
  RESULTS
  Twenty-one (81%) clinical trial rings had contraceptive hormone levels within the range of those used as a contraceptive choice. Five returned rings had unused or discordant levels of residual contraceptive hormones.
  
  
  CONCLUSIONS
  Residual vaginal ring drug levels could help assess adherence in clinical trials.
authors.affiliation: Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA, USA 30329. Electronic address: hyw9@cdc.gov.
authors.forename: Richard E
authors.initials: RE
authors.lastname: Haaland
authors.affiliation: Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA, USA 30329. Electronic address: fka5@cdc.gov.
authors.forename: Angela
authors.initials: A
authors.lastname: Holder
authors.affiliation: Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA, USA 30329. Electronic address: tae0@cdc.gov.
authors.forename: Tammy
authors.initials: T
authors.lastname: Evans-Strickfaden
authors.affiliation: KEMRI/CDC Research Field Station, P.O. Box 1578, Kisumu, Kenya. Electronic address: Bnyagol@kemricdc.org.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Nyagol
authors.affiliation: KEMRI/CDC Research Field Station, P.O. Box 1578, Kisumu, Kenya. Electronic address: mmakanga@kemricdc.org.
authors.forename: Mumbi
authors.initials: M
authors.lastname: Makanga
authors.affiliation: KEMRI/CDC Research Field Station, P.O. Box 1578, Kisumu, Kenya. Electronic address: Boyaro@kemricdc.org.
authors.forename: Boaz
authors.initials: B
authors.lastname: Oyaro
authors.affiliation: KEMRI/CDC Research Field Station, P.O. Box 1578, Kisumu, Kenya. Electronic address: FHumwa@kemricdc.org.
authors.forename: Felix
authors.initials: F
authors.lastname: Humwa
authors.affiliation: ICF International, Assigned to Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA 30329. Electronic address: wuq0@cdc.gov.
authors.forename: Tiffany
authors.initials: T
authors.lastname: Williams
authors.affiliation: Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA, USA 30329. Electronic address: egm4@cdc.gov.
authors.forename: Eleanor
authors.initials: E
authors.lastname: McLellan-Lemal
authors.affiliation: Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA, USA 30329. Electronic address: gdo5@cdc.gov.
authors.forename: Mitesh
authors.initials: M
authors.lastname: Desai
authors.affiliation: Emory University Student Health Services, Emory University School of Medicine, 1525 Clifton Road, Atlanta, GA, USA 30322. Electronic address: mhuey@emory.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Huey
mesh_terms: D000282:Administration, Intravaginal; D002986:Clinical Trials as Topic; D003271:Contraceptive Agents, Female / Q000008:administration & dosage / Q000032:analysis*; D003274:Contraceptive Devices, Female; D017135:Desogestrel / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000032:analysis; D004338:Drug Combinations; D004997:Ethinyl Estradiol / Q000008:administration & dosage / Q000032:analysis*; D005260:Female; D006801:Humans; D007630:Kenya; D010349:Patient Compliance; D014481:United States
chemical_list: D003271:Contraceptive Agents, Female; D004338:Drug Combinations; C516519:NuvaRing; C044815:etonogestrel; D004997:Ethinyl Estradiol; D017135:Desogestrel
keywords: Adherence; Contraception; HIV; Multipurpose technology; Vaginal ring