title: Adherence and discontinuation of adjuvant hormonal therapy  in breast cancer patients: a population-based study.
abstract: Adherence to long-term pharmacological treatment for chronic conditions is often less than optimal. Till date, a limited number of population-based studies have assessed adherence to adjuvant hormonal therapy in breast cancer, a therapy with proven benefits in terms of reductions of recurrence and mortality. We aimed to examine rates of adherence and early discontinuation in Sweden where prescribed medications are subsidized for all residents and made available at reduced out-of-pocket costs. Individual-level data were obtained from Regional Clinical Quality Breast Cancer Registers, the Swedish Prescribed Drug Register, and several other population-based registers. Multivariate logistic regression was used to analyze factors associated with adherence to prescribed medication for a period of 3 years. Between January 1 and December 31, 2005, 1,741 patients in central Sweden were identified with estrogen receptor positive breast cancer, and at least one prescription dispensation of either tamoxifen or an aromatase inhibitor. Of these women, 1,193 (69%) were fully adherent to therapy for 3 years (medication possession ratio of 80% or higher and a maximum of 180 days between refills). During the 3-year follow-up, 215 women (12%) had prematurely discontinued therapy. Adherence was positively associated with younger age, large tumor size, being married, and being born in the Nordic countries, while no clear association was observed with education or income. During the 3 years of follow-up, 31% of women were non-adherent to therapy. Further efforts must be undertaken to promote adherence over the entire recommended treatment period.
authors.affiliation: Regional Cancer Centre, Uppsala University Hospital, 751 85 Uppsala, Sweden. Annette.Wigertz@akademiska.se
authors.forename: Annette
authors.initials: A
authors.lastname: Wigertz
authors.forename: Johan
authors.initials: J
authors.lastname: Ahlgren
authors.forename: Marit
authors.initials: M
authors.lastname: Holmqvist
authors.forename: Tommy
authors.initials: T
authors.lastname: Fornander
authors.forename: Jan
authors.initials: J
authors.lastname: Adolfsson
authors.forename: Henrik
authors.initials: H
authors.lastname: Lindman
authors.forename: Leif
authors.initials: L
authors.lastname: Bergkvist
authors.forename: Mats
authors.initials: M
authors.lastname: Lambe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000517:prevention & control*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D016015:Logistic Models; D060046:Maintenance Chemotherapy; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control*; D009376:Neoplasms, Hormone-Dependent / Q000517:prevention & control*; D013548:Sweden; D013629:Tamoxifen / Q000627:therapeutic use*; D016903:Drug Monitoring
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D013629:Tamoxifen