title: A comparison of self-reported oral contraceptive use and automated pharmacy data in perimenopausal and early postmenopausal women.
abstract: OBJECTIVE
  Oral contraceptive (OC) use can occur throughout a woman's reproductive life span with the potential for long-term impacts on health. To assess potential measurement error in prior OC use, this study compared level of agreement between self-reported prior OC use and pharmacy dispensing data in perimenopausal and/or early postmenopausal women.
  
  
  METHODS
  The study's 1399 women (ages, 45-59 years) were participants in a population-based case-control study of the association between OC use and fracture risk. Episodes of lifetime self-reported OC use (in months) were collected, by telephone interview, for January 1, 2008 through November 25, 2012. Pharmacy fills, back to 1980, were collected from automated data. Agreement was measured using the prevalence-adjusted and bias-adjusted kappa index.
  
  
  RESULTS
  The number of women with OC pharmacy fills was 11% to 45% higher than those who reported OC use during each time period. Between-measures agreement was better for more recent use. Prevalence-adjusted and bias-adjusted kappa index values ranged from 0.88 (95% confidence interval, 0.85-0.90) within 5 years from the reference date to 0.65 (95% confidence interval, 0.59-0.71) within 15 to 20 years.
  
  
  CONCLUSIONS
  For studies designed to assess the long-term effects of OC use, the current results are reassuring in noting moderate agreement between self-reported OC use and pharmacy data for up to 15 to 20 years before the interview.
authors.affiliation: Center for Observational Research, Amgen Inc., Thousand Oaks, CA. Electronic address: leslie.spangler@amgen.com.
authors.forename: Leslie
authors.initials: L
authors.lastname: Spangler
authors.affiliation: Group Health Research Institute, Group Health Cooperative, Seattle, WA.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Ichikawa
authors.affiliation: Group Health Research Institute, Group Health Cooperative, Seattle, WA.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Hubbard
authors.affiliation: Group Health Research Institute, Group Health Cooperative, Seattle, WA.
authors.forename: Belinda
authors.initials: B
authors.lastname: Operskalski
authors.affiliation: Family and Preventive Medicine, University of California, San Diego, CA.
authors.forename: Andrea Z
authors.initials: AZ
authors.lastname: LaCroix
authors.affiliation: Department of Medicine, University of Washington, Seattle, WA.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Ott
authors.affiliation: Group Health Research Institute, Group Health Cooperative, Seattle, WA.
authors.forename: Delia
authors.initials: D
authors.lastname: Scholes
mesh_terms: D015982:Bias; D016022:Case-Control Studies; D003276:Contraceptives, Oral / Q000008:administration & dosage*; D004363:Drug Utilization / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008875:Middle Aged; D047648:Perimenopause; D010604:Pharmacy / Q000706:statistics & numerical data*; D011159:Population Surveillance; D017698:Postmenopause; D015203:Reproducibility of Results; D057566:Self Report; D013997:Time Factors; D014861:Washington
chemical_list: D003276:Contraceptives, Oral
keywords: Agreement; Contraceptives, oral; Kappa; Reproducibility of results