title: Endocrine therapy for breast cancer: assessing an array of women's treatment experiences and perceptions, their perceived self-efficacy and nonadherence.
abstract: BACKGROUND
  Although adjuvant endocrine therapy effectively prevents breast cancer recurrence, nonadherence rates are substantial. We therefore examined associations of women's experiences and perceptions regarding the efficacy, side effects, and practical problems of endocrine therapy with nonadherence. Furthermore, we examined whether women's perceived self-efficacy moderated these associations.
  
  
  METHODS
  Two hundred forty-one breast cancer patients participated. Using the electronic Tailored Medicine Inventory, which enables skipping of irrelevant items, experiences and perceptions were assessed in a comprehensive yet feasible manner. Adherence was assessed according to self-report and evaluated for agreement with adherence estimated from pharmacy refill data.
  
  
  RESULTS
  A substantial number of women doubted the efficacy of endocrine therapy, were worried about and/or had experienced hot flushes, loss of libido, joint ache, and/or practical problems with regard to information, intake, and packaging. Experience of practical problems (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.0-5.8) and perceived self-efficacy with regard to medicine intake (OR, 0.5; 95% CI, 0.4-0.7) were associated with unintentional nonadherence. Number of side effects experienced (OR, 1.2; 95% CI, 1.05-1.4) and perceived self-efficacy with regard to learning about medication (OR, 0.6; 95% CI, 0.4-0.96) were associated with intentional nonadherence. Perceived self-efficacy did not moderate associations between women's treatment experiences and perceptions and nonadherence.
  
  
  CONCLUSIONS
  Endocrine therapy is challenging for many women. Targeting women's specific experiences and perceptions and improving their perceived self-efficacy is likely to decrease intentional and unintentional nonadherence.
authors: Division of Pharmaco-Epidemiology and Clinical Pharmacology, Faculty of Science, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, Utrecht, The Netherlands. Electronic address: j.wouters@uu.nl.
authors: Hans
authors: H
authors: Wouters
authors: Department of Medical Decision-Making, Leiden University Medical Center, Leiden, The Netherlands.
authors: Anne M
authors: AM
authors: Stiggelbout
authors: Division of Pharmaco-Epidemiology and Clinical Pharmacology, Faculty of Science, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, Utrecht, The Netherlands.
authors: Marcel L
authors: ML
authors: Bouvy
authors: Division of Pharmaco-Epidemiology and Clinical Pharmacology, Faculty of Science, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, Utrecht, The Netherlands.
authors: Gemma A
authors: GA
authors: Maatman
authors: Division of Pharmaco-Epidemiology and Clinical Pharmacology, Faculty of Science, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, Utrecht, The Netherlands.
authors: Erica C G
authors: EC
authors: Van Geffen
authors: Department of Surgery, Diaconessenhuis Hospital, Leiden, The Netherlands.
authors: Robbert
authors: R
authors: Vree
authors: Department of Clinical Oncology, Leiden University Medical Center, Leiden, The Netherlands.
authors: Johan W
authors: JW
authors: Nortier
authors: NIVEL, Netherlands Institute for Health Services Research, Utrecht, The Netherlands.
authors: Liset
authors: L
authors: Van Dijk
mesh_terms: D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000523:psychology*; D005260:Female; D005500:Follow-Up Studies; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D055118:Medication Adherence / Q000523:psychology*; D008875:Middle Aged; D010465:Perception; D011379:Prognosis; D020377:Self Efficacy
chemical_list: D018931:Antineoplastic Agents, Hormonal
keywords: Antibreast cancer agents: adverse effects; Antibreast cancer agents: practical problems; Antibreast cancer agents: therapeutic use; Oncology: patient adherence; Oncology: patient-centered care