Delay discounting and adjuvant endocrine therapy adherence in hormone receptor-positive breast cancer.

Abstract

Objectives: Oral endocrine therapy improves survival among hormone responsive breast cancer (HRBC) survivors; however, 30-70% of patients are nonadherent. One patient-centered factor that may impact adherence is delay discounting (DD), or the degree to which patients value future outcomes. In prior research, DD is robustly associated with maladaptive health behavior; but no work to our knowledge has examined delay discounting and medication nonadherence in breast cancer patients. Study 1 examined cross-sectional associations between DD and endocrine therapy nonadherence. Study 2 examined whether DD in the HRBC population is amenable to a brief intervention-episodic future thinking (EFT), in which participants preexperience future events. Method: In Study 1, HRBC survivors completed assessments of DD and endocrine therapy adherence (pill count and self-report). In Study 2, participants were randomized to engage in a brief behavioral intervention (EFT) or a control condition, and again completed assessments of DD. Results: Eighty nine female HRBC survivors completed Studies 1 and 2. Controlling for other known risk factors, greater DD was significantly associated with poorer pill-count but not self-report adherence. In Study 2, the EFT intervention significantly reduced DD when compared to control episodic thinking. Conclusions: DD is associated with direct-observation (pill count) measures of endocrine therapy adherence in HRBC survivors, suggesting it is a potential therapeutic target for improving adherence. This target is also amenable to intervention with EFT.

Choice bundling, unpacked: Observed and predicted effects on intertemporal choice in an additive model of hyperbolic delay discounting

“…The dependent measure of intertemporal choice was indifference delay (in days), calculated as the adjusted value of D 1 after the final trial of the five-trial adjusting-delay task. This is similar to measures of indifference delay used and validated previously with discrete rewards [12,39,41,42]. Longer values of indifference delay reflect greater willingness to wait for LLRs.…”

“…Three additional questions were specific to the choice tasks. Because the five-trial task does not allow use of standardized diagnostic criteria to assess orderliness of obtained data [e.g., 40], these quality control questions were appended to the five-trial, adjusting-delay task, as has been done previously [12,38]. Specifically, in each of three bundle-size conditions, a sixth trial asked participants to choose between $500 now and $1000 now.…”

“…Estimates of discounting from this task also show strong concordance with those from the more common, but also more time-consuming, adjusting-amount task (e.g., r=.67-.86 for monetary rewards; [20,39,49]). Moreover, both tasks are sensitive to the same experimental manipulations [12,20,39,50,51] and cross-sectional associations with maladaptive health behavior [12,38,52].…”

“…Rewards are devalued as a function of the delay until they are received-a process known as delay discounting [1,2]. In observational studies, delay discounting is a robust marker of maladaptive health behaviors and outcomes, including tobacco, alcohol, and other substance use [3][4][5][6]; energy intake, sedentary activity, and obesity [7][8][9]; and nonadherence to medications for type 2 diabetes, breast cancer, hypertension, and high cholesterol [7,[10][11][12]. Additional evidence suggests that delay discounting may play an etiological role in lifestyle-related disease, as interventions that decrease and increase delay discounting also improve and worsen, respectively, the health behaviors with which delay discounting is associated, including consumption or valuation of cigarettes [e.g., 13,14], alcohol [e.g., 15], and obesogenic foods [e.g., 16-18; but also see 19,20].…”

Delay Discounting as a Potential Therapeutic Target for Weight Loss in Breast Cancer Survivors

“…A pilot study from our investigational team was the first to study DD specifically in a BC survivor cohort and demonstrated DD as a predictor of adjuvant endocrine therapy non-adherence in 89 participants. This study found that treatment adherence was higher in participants showing greater willingness to wait for larger, delayed rewards (i.e., lower DD) (standardized beta = 0.328, p = 0.005) [ 39 ]. These findings suggest that DD does impact lifestyle behaviors in BC survivors similar to other populations and strategies to reduce DD may be efficacious to improve long-term survival.…”