title: Association between self-report adherence measures and oestrogen suppression among breast cancer survivors on aromatase inhibitors.
abstract: OBJECTIVE
  Poor adherence to oral adjuvant hormonal therapy for breast cancer is a common problem, but little is known about the relationship between self-report adherence measures and hormonal suppression. We evaluated the relationship of three self-report measures of medication adherence and oestrogen among patients on aromatase inhibitors (AIs).
  
  
  METHODS
  We recruited 235 women with breast cancer who were prescribed AI therapy. Participants self-reported AI adherence by completing the following: (1) a single item asking whether they took an AI in the last month, (2) a modified Morisky Medication Adherence Scale-8 (MMAS-8) and (3) the Visual Analog Scale (VAS). Serum estrone and estradiol were analysed using organic solvent extraction and Celite column partition chromatography, followed by radioimmunoassay.
  
  
  RESULTS
  Ten percent of participants reported they had not taken an AI in the last month and among this group, median estrone (33.2 pg/ml [interquartile range (IQR)=22.3]) and estradiol levels (7.2 pg/mL [IQR=3.3]) were significantly higher than those in participants who reported AI use (median estrone=11.5 pg/mL [IQR=4.9]; median estradiol=3.4 pg/mL [IQR=2.1]; p<0.001). This relationship held when controlling for race and AI drug type.
  
  
  CONCLUSIONS
  A single-item monthly-recall adherence measure for AIs was associated with oestrogen serum levels. This suggests that patient-reported monthly adherence may be a useful measure to identify early non-adherence behaviour and guide interventions to improve patient adherence to hormonal treatment.
authors.affiliation: Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Moriah J
authors.initials: MJ
authors.lastname: Brier
authors.affiliation: Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Dianne
authors.initials: D
authors.lastname: Chambless
authors.affiliation: University of Pennsylvania School of Medicine and Philadelphia Veterans Administration Medical Center, Philadelphia, PA, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Gross
authors.affiliation: University of California, San Diego, School of Medicine, San Diego, CA, USA.
authors.forename: H Irene
authors.initials: HI
authors.lastname: Su
authors.affiliation: University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Angela
authors.initials: A
authors.lastname: DeMichele
authors.affiliation: University of Pennsylvania School of Medicine, Philadelphia, PA, USA. Electronic address: Jun.Mao@uphs.upenn.edu.
authors.forename: Jun J
authors.initials: JJ
authors.lastname: Mao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000097:blood*; D001943:Breast Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D016903:Drug Monitoring / Q000379:methods; D004958:Estradiol / Q000097:blood*; D004970:Estrone / Q000097:blood*; D005260:Female; D006801:Humans; D055118:Medication Adherence; D008875:Middle Aged; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D010414:Pennsylvania; D011237:Predictive Value of Tests; D057566:Self Report; D016896:Treatment Outcome
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D014408:Biomarkers, Tumor; D004970:Estrone; D004958:Estradiol
keywords: Aromatase inhibitors; Breast neoplasms; Medication adherence; Self-report