Abstract PD10-08: Baseline patient reported outcomes predict aromatase inhibitor adherence failure among women in enrolled in a randomized trial of text-messaging
Authors: Hershman Dawn L , Unger Joeseph M , Moseley Anna , Hillyer Grace C , Arnold Kathryn B. , Gralow Julie R , Henry N. Lynn , Ramsey Scott D , Neugut Alfred I 
Published: March 2020

Abstract
Background: Non-adherence to aromatase inhibitors (AIs) for breast cancer is common and increases risk of recurrence. Few prospective studies have systematically evaluated reasons for adherence failure. S1105 randomized women to receive text message reminders or usual care, and no effect of the intervention was observed on the rates of adherence failure. We analyzed baseline characteristics to evaluate factors associated with non-adherence prospectively over 3-years.Methods: Patients enrolled in SWOG S1105 were required to have been on an AI for ≥30 days at enrollment. Patients were assessed for non-adherence of AIs every 3 months for 36 months, with non-adherence defined as urine AI metabolite assay results satisfying any of the following: &lt;10 [units], undetectable, specimen submitted outside of the ± 21 day follow-up appointment window, or no submitted specimen. At baseline patients were asked about insurance, pill number dispensed (30 vs 90) and medication cost, and they completed patient reported outcomes (PROs) focused on pain and endocrine symptoms (BPI (Brief Pain Inventory), FACT-ES (Endocrine Symptoms)), quality of life (FACT-G), as well as their beliefs about medications (TSQM (Treatment Satisfaction Questionnaire for Medicine) and BMQ (Brief Medication Questionnaire)). PRO scales were split at the median creating high (&gt;median) vs low (&lt;=median) binary predictors. We examined the association of baseline factors with both adherence failure at 36 months with a logistic regression and time-to-adherence failure (TTAF) with a cox proportional hazard regression controlling for stratification factors. Results: In total, 724 patients were registered from 40 institutions between May, 2012 and September, 2013. The median age was 60.9 years, and 64.5% were on AI &lt;12 months prior to registration. Observed adherence at 36 months was 55.4% (41.2% in-window, 14.2% out of window). Neither age nor race nor ethnicity was associated with long-term adherence. Of the 29 baseline factors we analyzed, 12 were associated with non-adherence at 36 months, including symptoms (FACT-ES total, OR=1.64, 95% CI:1.2, 2.22 p=.002; BPI Interference OR=1.68, 95% CI:1.23,2.28 p=.001; FACT G, OR=1.70, 95% CI:1.25, 2.31 p&lt;.001), satisfaction with medications (TSQM global, OR=1.55, 95% CI:1.1,2.17 p=.01) and beliefs about medication (BMQ, OR=1.51, 95% CI:1.11, 2.05 p=.009). Nine of 29 baseline factors were associated with TTAF, including lack of private insurance (HR=1.20, 95% CI:1.01,1.41 p=.04) and 30 day vs. 90 day pill supply (HR=1.2, 95% CI:1.01,1.42 p=.04). Factors associated with self-reported adherence will be presented. Conclusions: Baseline endocrine symptoms, pain, medication satisfaction, beliefs and concerns about side effects are strongly associated with long-term AI adherence. Targeted behavioral and symptom management interventions to improve adherence should be focused on women at the highest risk of adherence failure.
Citation Format: Dawn L Hershman, Joeseph M Unger, Anna Moseley, Grace C Hillyer, Kathryn B. Arnold, Julie R Gralow, N. Lynn Henry, Scott D Ramsey, Alfred I Neugut. Baseline patient reported outcomes predict aromatase inhibitor adherence failure among women in enrolled in a randomized trial of text-messaging [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD10-08.