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Informing interventions to improve uptake of adjuvant endocrine therapy in women with breast cancer: a theoretical-based examination of modifiable influences on non-adherence

Lookup NU author(s): Dr Stephan Dombrowski, Professor Linda Sharp



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


© 2023. The Author(s). PURPOSE: To inform intervention development, we measured the modifiable determinants of endocrine therapy (ET) non-adherence in women with breast cancer, using the Theoretical Domains Framework (TDF) and examined inter-relationships between these determinants and non-adherence using the Perceptions and Practicalities Approach (PAPA). METHODS: Women with stages I-III breast cancer prescribed ET were identified from the National Cancer Registry Ireland (N = 2423) and invited to complete a questionnaire. A theoretically based model of non-adherence was developed using PAPA to examine inter-relationships between the 14 TDF domains of behaviour change and self-reported non-adherence. Structural equation modelling (SEM) was used to test the model. RESULTS: A total of 1606 women participated (response rate = 66%) of whom 395 (25%) were non-adherent. The final SEM with three mediating latent variables (LVs) (PAPA Perceptions: TDF domains, Beliefs about Capabilities, Beliefs about Consequences; PAPA Practicalities: TDF domain, Memory, Attention, Decision Processes and Environment) and four independent LVs (PAPA Perceptions: Illness intrusiveness; PAPA Practicalities: TDF domains, Knowledge, Behaviour Regulation; PAPA External Factors: TDF domain, Social Identity) explained 59% of the variance in non-adherence and had an acceptable fit (χ2(334) = 1002, p < 0.001; RMSEA = 0.03; CFI = 0.96 and SRMR = 0.07) Knowledge had a significant mediating effect on non-adherence through Beliefs about Consequences and Beliefs about Capabilities. Illness intrusiveness had a significant mediating effect on non-adherence through Beliefs about Consequences. Beliefs about Consequences had a significant mediating effect on non-adherence through Memory, Attention, Decision Processesg and Environment. CONCLUSIONS: By underpinning future interventions, this model has the potential to improve ET adherence and, hence, reduce recurrence and improve survival in breast cancer.

Publication metadata

Author(s): Cahir C, Bennett K, Dombrowski SU, Kelly CM, Wells M, Watson E, Sharp L

Publication type: Article

Publication status: Published

Journal: Supportive Care in Cancer

Year: 2023

Volume: 31

Issue: 3

Online publication date: 04/03/2023

Acceptance date: 22/02/2023

Date deposited: 15/06/2023

ISSN (print): 0941-4355

ISSN (electronic): 1433-7339

Publisher: Springer Nature


DOI: 10.1007/s00520-023-07658-x

PubMed id: 36869943


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