title: Factors associated with intentional and unintentional non-adherence to adjuvant endocrine therapy following breast cancer.
abstract: Adherence to adjuvant endocrine therapy (AET) following breast cancer is known to be suboptimal despite its known efficacy in reducing recurrence and mortality. This study aims to investigate factors associated with non-adherence and inform the development of interventions to support women and promote adherence. A questionnaire survey to measure level of adherence, side effects experienced, beliefs about medicine, support received and socio-demographic details was sent to 292 women 2-4 years post breast cancer diagnosis. Differences between non-adherers and adherers to AET were explored, and factors associated with intentional and unintentional non-adherence are reported. Approximately one quarter of respondents, 46 (22%), were non-adherers, comprising 29 (14%) intentional non-adherers and 17 (8%) unintentional non-adherers. Factors significantly associated with intentional non-adherence were the presence of side effects (p < .03), greater concerns about AET (p < .001) and a lower perceived necessity to take AET (p < .001). Half of the sample (105/211) reported that side effects had a moderate or high impact on their quality of life. Factors associated with unintentional non-adherence were younger age (<65) (p < .001), post-secondary education (p = .046) and paid employment (p = .031). There are distinct differences between intentional non-adherence and unintentional non-adherence. Differentiation between the two types of non-adherence may help tailor support and advice interventions.
authors.affiliation: Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK.
authors.forename: J
authors.initials: J
authors.lastname: Brett
authors.affiliation: Faculty of Health Sciences, University of Southampton, Southampton, UK.
authors.forename: D
authors.initials: D
authors.lastname: Fenlon
authors.affiliation: Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK.
authors.forename: M
authors.initials: M
authors.lastname: Boulton
authors.affiliation: Department of Psychology, Chester Research Unit for the Psychology of Health (CRUPH), University of Chester, Chester, UK.
authors.forename: N J
authors.initials: NJ
authors.lastname: Hulbert-Williams
authors.affiliation: Primary Care Cancer Research, Lucy Cavendish College, Cambridge University, Cambridge, UK.
authors.forename: F M
authors.initials: FM
authors.lastname: Walter
authors.affiliation: South Devon Healthcare NHS Foundation Trust, Torbay Hospital, Torquay, UK.
authors.forename: P
authors.initials: P
authors.lastname: Donnelly
authors.affiliation: Cancer Services, Churchill Site, Oxford University, Hospitals Foundation NHS Trust, Oxford, UK.
authors.forename: B
authors.initials: B
authors.lastname: Lavery
authors.affiliation: Independent Cancer Patient Voice, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Morgan
authors.affiliation: Independent Cancer Patient Voice, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Morris
authors.affiliation: Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK.
authors.forename: E
authors.initials: E
authors.lastname: Watson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000730:Androstadienes / Q000627:therapeutic use*; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy*; D017024:Chemotherapy, Adjuvant; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D016903:Drug Monitoring
chemical_list: D000730:Androstadienes; D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors
keywords: 
  BMQ
  ; adjuvant endocrine therapy; breast cancer; intentional non-adherence; non-adherence; side effects