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

Caitriona Cahir; Kathleen Bennett; Stephan U Dombrowski; Catherine M Kelly; Mary Wells; Eila Watson; Linda Sharp

doi:10.1007/s00520-023-07658-x

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

Support Care Cancer. 2023 Mar 4;31(3):200. doi: 10.1007/s00520-023-07658-x.

Authors

Caitriona Cahir¹, Kathleen Bennett², Stephan U Dombrowski³, Catherine M Kelly⁴, Mary Wells⁵, Eila Watson⁶, Linda Sharp⁷

Affiliations

¹ Data Science Centre, School of Population Heath Sciences, RCSI University of Medicine and Health Sciences, Dublin, Ireland. caitrionacahir@rcsi.ie.
² Data Science Centre, School of Population Heath Sciences, RCSI University of Medicine and Health Sciences, Dublin, Ireland.
³ Faculty of Kinesiology, University of New Brunswick, Fredericton, Canada.
⁴ Mater Private Hospital, Dublin, Ireland.
⁵ Imperial College Healthcare NHS Trust, Imperial College London, London, UK.
⁶ Oxford Institute of Nursing, Midwifery and Allied Health Research (OxINMAHR), Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK.
⁷ Population Health Sciences Institute, Newcastle University Centre for Cancer, Newcastle University, Newcastle upon Tyne, UK.

Abstract

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.

Keywords: Adherence; Breast cancer; Endocrine therapy; Intervention development.

MeSH terms

Adjuvants, Immunologic
Adjuvants, Pharmaceutic
Breast Neoplasms*
Combined Modality Therapy
Female
Humans
Ireland

Substances

Adjuvants, Immunologic
Adjuvants, Pharmaceutic

Abstract

MeSH terms

Substances

Grants and funding