Personal and clinical social support and adherence to adjuvant endocrine therapy among hormone receptor-positive breast cancer patients in an integrated health care system

• DOI: 10.1007/s10549-018-4774-2
• Publication Date: 2018-04-18T07:48:21Z
• Authors: Candyce H. Kroenke; Dawn L. Hershman; Scarlett L. Gomez; Sara R. Adams; Elizabeth H. Eldr...; Marilyn L. Kwan; Isaac J. Ergas; Ai Kubo; Lawrence H. Kushi
• Keywords: Antineoplastic Agents, Hormonal; Delivery of Health Care, Integrated; 1. No poverty; Disease Management; Social Support; Breast Neoplasms; Comorbidity; Combined Modality Therapy; Severity of Illness Index; Medication Adherence; 3. Good health; 03 medical and health sciences; 0302 clinical medicine; Receptors, Estrogen; Socioeconomic Factors; Chemotherapy, Adjuvant; Biomarkers, Tumor; Humans; Female; Public Health Surveillance; Receptors, Progesterone; Follow-Up Studies; Proportional Hazards Models

We evaluated associations between personal and clinical social support and non-adherence to adjuvant endocrine therapy (AET) in a large, Northern California breast cancer (BC) cohort from an integrated healthcare network.This study included 3382 women from the Pathways Study diagnosed from 2005 to 2013 with stages I-III hormone receptor-positive BC and who responded to the Medical Outcomes Study Social Support and Interpersonal Processes of Care surveys, approximately 2 months post-diagnosis. We used logistic regression to evaluate associations between tertiles of social support and non-initiation (< 2 consecutive prescription fills within a year after diagnosis). Among those who initiated treatment, we used proportional hazards regression to evaluate associations with discontinuation (≥ 90 day gap) and non-adherence (< 80% medical possession ratio).Of those who initiated AET (79%), approximately one-fourth either discontinued AET or were non-adherent. AET non-initiation was more likely in women with moderate (adjusted OR 1.18, 95% CI 0.96-1.46) or low (OR 1.30, 95% CI 1.05-1.62) versus high personal social support (P trend = 0.02). Women with moderate (HR 1.20, 95% CI 0.99-1.45) or low (HR 1.32, 95% CI 1.09-1.60) personal social support were also more likely to discontinue treatment (P trend = 0.01). Furthermore, women with moderate (HR 1.25, 95% CI 1.02-1.53) or low (HR 1.38, 95% CI 1.12-1.70) personal social support had higher non-adherence (P trend = 0.007). Associations with clinical social support and outcomes were similar. Notably, high clinical social support mitigated the risk of discontinuation when patients' personal support was moderate or low (P value = 0.04).Women with low personal or clinical social support had higher AET non-adherence. Clinician teams may need to fill support gaps that compromise treatment adherence.