Role of delay discounting in predicting change in HBA1c for individuals with prediabetes

Intertemporal Decision-Making, Diabetes Self-Management, and Health Outcomes in Patients With Type 2 Diabetes

PURPOSE

The purpose of this study was to identify the independent factors associated with intertemporal decision-making and to examine its relationship with diabetes self-management behaviors, glucose variability, and diabetes complications in patients with diabetes.

METHODS

A cross-sectional study using convenience sampling (n = 368) was conducted in patients with type 2 diabetes (T2DM) between November 2021 and April 2023. Data were collected using self-reported questionnaires and retrieval of clinical information from medical records. Intertemporal decision-making was operationalized using delay discounting. The outcome variables included diabetes self-management behaviors, A1C, diabetic retinopathy, and carotid artery disease. Hierarchical regression and binary logistic regression models were used to explore the relationships among intertemporal decision-making, self-management, A1C, and carotid artery disease.

RESULTS

The analyses showed that intertemporal decision-making was negatively associated with physical activity and carotid artery disease, in which individuals with lower delay discounting tended to have healthier physical activity; when the delay discounting rate increased 1 unit, the risk of the carotid artery disease increased by 39.8%.

CONCLUSIONS

The study reveals that a lower delay discounting can promote healthier physical activity and decrease the incidence of carotid artery disease. These results offer new knowledge for researchers and clinicians to consider intertemporal decision-making in developing interventional programs to improve physical activity and reduce carotid artery complication in patients with T2DM when providing care.

Differential signaling effects of blood glucose on delay discounting in individuals with and without type 1 diabetes

Based on the signaling hypothesis of blood glucose (BG), a rise in BG levels signals a positive energy budget for healthy individuals but cellular starvation for individuals with type 1 diabetes. We examined this novel prediction and its intervention implications in the context of delay discounting, the degree to which delayed rewards are discounted, and the regulatory effects of insulin ingestion. We recruited 44 adults with type 1 diabetes (mean age 30.8 years, diabetes duration 15.4 years) and recorded their BG levels. The delay discounting rate was measured using the intertemporal choice task, where participants were required to choose between sets of smaller-and-sooner (SS) and larger-and-later (LL) rewards. In addition, 82 age-matched healthy participants were recruited to provide a baseline comparison on delay discounting. Random forest analysis showed that among many diagnostic factors, delay discounting was most dominating in differentiating the individuals with type 1 diabetes from the control participants. A hierarchical linear mixed model revealed that participants with type 1 diabetes had a stronger preference for SS rewards (p < .001) after controlling for covariates. Participants who had insulin delivered before the last meal exhibited a stronger preference for LL rewards compared to after-meal delivery. In contrast, subjective measures (e.g., self-reported hunger) failed to predict the participants' actual BG levels and delay discounting rates. In sum, individuals with type 1 diabetes tend to discount future rewards excessively compared to the control participants. Pre-meal insulin ingestion was associated with a higher LL preference for future rewards.

Relationship Between Delay Discounting and Clinical Diabetes Outcomes: A Systematic Review

OBJECTIVE

To evaluate the evidence on the relationship between delay discounting and clinical diabetes outcomes, identify current measures, and recommend areas for future work.

METHODS

A reproducible search using OVID Medline, PsycINFO, PubMed, Science Direct, and Scopus was conducted. Articles published from database creation up to March 2024 were searched. Medical Subject Heading (MeSH) terms and keywords representing delay discounting and diabetes were used. Outcomes included hemoglobin A1c (HbA1c), LDL, body mass index (BMI), blood pressure, quality of life (QOL), psychosocial factors, self-care behaviors, and diabetes complications.

RESULTS

A total of 15 articles met the inclusion criteria and were included for final synthesis. Overall, 14 studies included in this review found a significant relationship between delay discounting and diabetes-related outcomes, such that higher delay discounting is significantly related to worse diabetes outcomes for HbA1c, self-care behaviors, BMI, stress, and quality of life across self-reported measures of delay discounting and delay discounting tasks.

CONCLUSIONS

Evidence supports the relationship between delay discounting and diabetes-related outcomes and self-care behaviors across measures of delay discounting and type of diabetes. To understand delay discounting as a mechanism driving diabetes outcomes and to develop targeted interventions, additional work using a multidisciplinary approach is needed to validate the construct, identify pathways, and refine intervention approaches that can be tested to improve population health.

Perceptions and effectiveness of episodic future thinking as digital micro-interventions based on mobile health technology

Objective

Delay discounting denotes the tendency for humans to favor short-term immediate benefits over long-term future benefits. Episodic future thinking (EFT) is an intervention that addresses this tendency by having a person mentally "pre-experience" a future event to increase the perceived value of future benefits. This study explores the feasibility of using mobile health (mHealth) technology to deliver EFT micro-interventions. Micro-interventions are small, focused interventions aiming to achieve goals while matching users' often limited willingness or capacity to engage with interventions. We aim to explore whether EFT delivered as digital micro-interventions can reduce delay discounting, the users' perceptions, and if there are differences between regular EFT and goal-oriented EFT (gEFT), a variant where goals are embedded into future events.

Method

A randomized study was conducted with 208 participants allocated to either gEFT, EFT, or a control group for a 21-day study.

Results

Results indicate intervention groups when combined achieved a significant reduction of Δ log k = - .80 in delay discounting (p = .017 ) compared to the control. When split into gEFT and EFT separately only the reduction of Δ log k = .96 in EFT delay discounting was significant (p = .045 ). We further explore and discuss thematic user perceptions.

Conclusions

Overall, user perceptions indicate gEFT may be slightly better for use in micro-interventions. However, perceptions also indicate that audio-based EFT micro-interventions were not always preferable to users, with findings suggesting that future EFT micro-interventions should be delivered using different forms of multimedia based on user preference and context and supported by other micro-interventions to maintain interest.

Episodic future thinking in type 2 diabetes: Further development and validation of the Health Information Thinking control for clinical trials

Episodic Future Thinking (EFT) reduces delay discounting and may have the potential as a clinical tool to increase the likelihood of health-promoting behaviors. However, evaluations of EFT in clinical settings require control conditions that match the effort and frequency of cue generation, as well as participants' expectations of improvement. The Health Information Thinking (HIT) control addresses these issues, but how this control affects delay discounting in individuals with diabetes and obesity when utilizing diabetes-management specific health-information vignettes is unknown. Moreover, little research has explored whether EFT reduces delay discounting in individuals with type 2 diabetes. To this end, we examined the impact of EFT, HIT, and a secondary no-cue control condition (NCC; assessments as usual) on delay discounting in 434 adults with self-reported type 2 diabetes and obesity recruited using Amazon Mechanical Turk. After completing an initial screening questionnaire, eligible participants reported demographics, then were randomized to EFT, HIT, or NCC conditions. Following the generation of seven EFT or HIT cues, participants assigned to EFT or HIT conditions completed a delay discounting task while imagining EFT or HIT cues; no-cue participants completed the task without cues. EFT participants demonstrated significantly lower delay discounting levels than HIT or NCC participants; no differences in delay discounting between HIT and NCC participants were observed. These results suggest that engaging in EFT, but not diabetes-specific HIT, results in lower delay discounting in adults with type 2 diabetes and obesity. This provides further evidence for the appropriateness of the HIT control for clinical trials examining the effect of EFT on delay discounting in adults with self-reported type 2 diabetes.

Disrupting future discounting: a commentary on an underutilised psychological approach for improving adherence to diet and physical activity interventions

Non-communicable diseases (NCD) such as CVD and type 2 diabetes mellitus are major contributors to the burden of disease. NCD are largely driven by modifiable lifestyle factors including poor diet and insufficient physical activity, and consequently, prevention is a public health priority. Although diet and physical activity levels can be improved via lifestyle interventions, long-term adherence to such interventions remains low, which limits their effectiveness. Thus, it is critical to identify the underlying mechanisms that challenge uptake and adherence to such interventions. The current commentary discusses an important, but underexplored, psychological driver of poor adherence to lifestyle interventions, namely, future discounting, which describes the tendency to prefer smaller, short-term rewards over larger, long-term rewards. For example, in the nutrition domain, future discounting refers to valuing the immediate reward of excessive intake of energy-dense, nutrient-poor, discretionary foods high in salt, sugar, and saturated fat, and insufficient intake of low-energy, nutrient-dense, whole foods such as vegetables. Prominent theoretical models propose that excessive future discounting is a major contributor to the development of unhealthy lifestyle behaviours. Furthermore, a vast body of evidence suggests that future discounting plays a key role in risk of NCD. Thus, the evidence to date supports the idea that future discounting is an important multi-behaviour target for supporting lifestyle behaviour change; however, this approach has been largely neglected in preventive health efforts. Furthermore, this commentary discusses promising techniques (e.g. Episodic Future Thinking) for disrupting future discounting to promote improved adherence to lifestyle interventions aimed at reducing NCD risk.

Time and risk preferences and the perceived effectiveness of incentives to comply with diabetic retinopathy screening among older adults with type 2 diabetes

Behavioral economics has the potential to inform the design of incentives to improve disease screening programs by accounting for various behavioral biases. We investigate the association between multiple behavioral economics concepts and the perceived effectiveness of incentive strategies for behavioral change among older patients with a chronic disease. This association is examined by focusing on diabetic retinopathy screening, which is recommended but very variably followed by persons living with diabetes. Five time and risk preference concepts (i.e., utility curvature, probability weighting, loss aversion, discount rate, and present-bias) are estimated simultaneously in a structural econometric framework, based on a series of deliberately-designed economic experiments offering real money. We find that higher discount rates and loss aversion and lower probability weighting are significantly associated with lower perceived effectiveness of intervention strategies whereas present-bias and utility curvature have an insignificant association with it. Finally, we also observe strong urban vs. rural heterogeneity in the association between our behavioral economic concepts and the perceived effectiveness of intervention strategies.

Effects of 6-month episodic future thinking training on delay discounting, weight loss and HbA1c changes in individuals with prediabetes

People with prediabetes are at risk for type 2 diabetes. They may discount the future delay discounting (DD), and not engage in preventive health behaviors. Episodic future thinking (EFT) can reduce DD when future scenarios are cued, but research is needed to assess long-term effects of EFT and when EFT is not cued. This study tested EFT training compared to control for people with prediabetes enrolled in a 6-month weight loss program on DD, weight, HbA1c, and physical activity. Results showed a reliable EFT effect on reducing DD in cued (p = 0.0035), and uncued DD tasks (p = 0.048), and significant overall changes in weight (p < 0.001), HbA1c (p, 0.001) and physical activity (p = 0.003), but no significant differences in these outcomes by group (p’s > 0.05). Sixty-eight percent of the sample ended below the prediabetes HbA1c range. These results suggest that DD can be modified over extended periods, and the effects of EFT can be observed without EFT cues. However, these data do not suggest that changes in weight, HbA1c or physical activity were due to EFT training. The study was initiated before the COVID-19 pandemic which provided the opportunity to compare differences for people treated in-person or remotely. Analyses showed no differences in DD, weight, HBA1c or physical activity outcomes were observed between in-person and remote treatment, suggesting telehealth is a scalable approach to treating prediabetes.

Imagine to Remember: An Episodic Future Thinking Intervention to Improve Medication Adherence in Patients with Type 2 Diabetes

PURPOSE

Medication nonadherence is prevalent in diabetic populations, with "forgetting" a commonly cited reason. This issue of forgetfulness is due, in part, to a failure of prospective memory (PM). Episodic future thinking (EFT) has been shown to improve PM but has not been used to improve medication adherence.

PATIENTS AND METHODS

The current study used a multiple baseline design (N = 4) to test the effects of EFT on medication non-adherence for four patients with a diagnosis of type 2 diabetes or prediabetes, with comorbid high blood pressure or high cholesterol. Medication adherence was objectively measured over 15 weeks using medication event monitoring systems.

RESULTS

Results of visual analysis showed medication adherence was reliably improved, confirmed by mixed model analysis of variance (p < 0.001), with significant differences from baseline to treatment (Tau <0.05) for 3 of 4 participants. Improvements in two measures of PM (effect size (ES) = 0.73, 0.80) and delay discounting (ES = 1.20) were observed.

CONCLUSION

This study provides a feasible way to improve medication adherence in patients with prediabetes or type 2 diabetes.

Temporal discounting as a candidate behavioral marker of obesity

Although obesity is a result of processes operating at multiple levels, most forms result from decision-making behavior. The aim of this review was to examine the candidacy of temporal discounting (TD) (i.e. the reduction in the value of a reinforcer as a function of the delay to its receipt) as a behavioral marker of obesity. For this purpose, we assessed whether TD has the ability to: identify risk for obesity development, diagnose obesity, track obesity progression, predict treatment prognosis/outcomes, and measure treatment effectiveness. Three databases (Pubmed, PsycINFO, and Web of Science) were searched using a combination of terms related to TD and obesity. A total of 153 papers were reviewed. Several areas show strong evidence of TD's predictive utility as a behavioral marker of obesity (e.g., distinguishing obese from non obese). However, other areas have limited and/or mixed evidence (e.g., predicting weight change). Given the positive relationship for TD in the majority of domains examined, further consideration for TD as a behavioral marker of obesity is warranted.

Novel, Neuroscience-Informed Approaches to Trauma Care in Community Clinical Settings

Trauma exposure, a highly prevalent condition in the United States, results in the development of chronic physical and mental health disabilities, such as diabetes, cardiovascular disease and posttraumatic stress disorder. Bench science advances in neurobiology and neuroscience have been translated into exciting clinical interventions, which have been shown to improve mental functioning and stress response. This article highlights three such interventions in hospital, primary care and community settings.

A story to tell: the role of narratives in reducing delay discounting for people who strongly discount the future

Delay Discounting (DD) or devaluing a future, larger reward in favour of a smaller, more immediate reward, has been linked to negative health behaviours. One intervention that reduces DD is Episodic Future Thinking (EFT). EFT has participants generate cues representing positive future events that correspond to temporal windows during the DD task. The current study examined if incorporating EFT cues into narratives would strengthen effects on DD. One hundred and sixty adults were recruited from Amazon Mechanical Turk and were randomised to traditional or narrative EFT. Results showed that participants in narrative EFT discounted the future less (p = 0.034) than participants who engaged in traditional EFT. This novel approach to EFT is well grounded in research and theory on the power of narratives to influence behaviour and can open a new window into ways to reduce DD to strengthen engagement in positive choices.

Examining the Relationship Between Delay Discounting, Delay Aversion, Diabetes Self-care Behaviors, and Diabetes Outcomes in U.S. Adults With Type 2 Diabetes

OBJECTIVE

Delay discounting and delay aversion are emerging areas for understanding diabetes management; however, few data exist on their relationship with multiple diabetes self-care behaviors and diabetes outcomes.

RESEARCH DESIGN AND METHODS

This cross-sectional study included 356 adults with type 2 diabetes across three racial/ethnic groups receiving care from two primary care clinics. The primary predictors were delay discounting and delay aversion. Outcomes included self-care behaviors, quality of life (QOL; mental health component score [MCS], physical component score), and A1C. Multiple linear regression models were run to examine the association between predictors and the outcomes, A1C, QOL, and each self-care behavior.

RESULTS

Higher delay discounting was associated with lower engagement in self-care behaviors for general diet (B = -0.06; 95% CI -0.12; -0.01), specific diet (B = -0.07; 95% CI -0.12; -0.03), and foot care (B = -0.10; 95% CI -0.17; -0.02). Higher delay aversion was associated with lower engagement in self-care behaviors for general diet (B = -0.06; 95% CI -0.10; -0.01), specific diet (B = -0.03; 95% CI -0.07; -0.01), foot care (B = -0.11; 95% CI -0.17; -0.05), and lower MCS (B = -0.38; 95% CI -0.71; -0.06).

CONCLUSIONS

In a diverse sample of adults with type 2 diabetes, higher delay discounting and higher delay aversion were significantly related to lower engagement in self-care behaviors. High delay aversion was specifically related to lower QOL. These findings offer new knowledge by highlighting the role that delay-related behaviors may have in the performance of self-care behaviors and the impact on QOL. Work is needed to further elucidate these relationships. Specifically, these results highlight the importance of targeting value and decision-making for diabetes self-management.

Delay Discounting, Glycemic Regulation and Health Behaviors in Adults with Prediabetes

The majority of people with prediabetes transition to type 2 diabetes. Research has suggested that persons with type 2 diabetes are likely to discount the future and focus on immediate rewards. This study was designed to assess whether this process of delay discounting (DD) is associated with glycemic regulation, medication adherence and eating and exercise behaviors in adults with prediabetes. Participants included 81 adults with prediabetes who were also prescribed hypertension or dyslipidemia drugs, which is common for people with prediabetes. Participants completed adjusting amount DD $100 and $1000 tasks, as well assessments of glycemic control (Hemoglobin (Hb) A1c), medication adherence, diet quality, and objectively measured physical activity. Relationships between DD and these variables were assessed. Results showed higher rates of DD were related to higher HbA1c; as well as poorer medication adherence, lower diet quality and lower physical activity. Hierarchical regression showed that the association between minority status, a known risk factor for type 2 diabetes, was moderated by DD, as minorities with higher DD had greater HbA1c values. Delay discounting may represent a novel target to prevent progression from prediabetes to type 2 diabetes.

Bleak present, bright future: II. Combined effects of episodic future thinking and scarcity on delay discounting in adults at risk for type 2 diabetes

The present study sought to determine if episodic future thinking (EFT) can decrease delay discounting (DD) and demand for fast food under simulations of economic scarcity in adults at risk for diabetes (i.e., overweight/obese and with hemoglobin A1c values in, or approaching, the prediabetic range). Across two sessions, participants completed assessments of DD and food demand at baseline and while prompted to: (1) engage in either EFT or control episodic recent thinking, and (2) while reading a brief narrative describing either economic scarcity or neutral income conditions. Results showed that EFT significantly reduced DD, whereas the economic scarcity narrative significantly increased DD; no significant interaction between EFT and scarcity was observed. No significant effect of either EFT or scarcity was observed on food demand. We conclude that EFT decreases DD even when challenged by simulated economic scarcity in adults at risk for diabetes. The absence of a significant interaction between EFT and scarcity suggests that these variables operate independently to influence DD in opposing directions. Effects of EFT and economic scarcity on food demand require further study. The present study was registered on clinicaltrials.gov (NCT03664726).

Does Episodic Future Thinking Repair Immediacy Bias at Home and in the Laboratory in Patients With Prediabetes?

OBJECTIVE

This study aimed to determine if episodic future thinking (EFT) can decrease delay discounting (DD) among adults with prediabetes both in and out of the laboratory. DD measures how much the value of a reinforcer decreases as a function of the delay to receive it.

METHODS

Adults with prediabetes (n = 67) completed a three-session study. At session 1, baseline measures (including DD) were collected. At sessions 2 and 3, participants were prompted to engage in either EFT or control episodic thinking (CET) while completing DD and other measures. In addition, between the completion of sessions 2 and 3, participants engaged in EFT or CET at home and completed DD tasks remotely via smartphones or other Internet-connected devices.

RESULTS

Results showed significant -1.2759 (-20.24%) reductions in DD in the EFT group compared with a + 0.0287 (+0.46%) DD increase in the CET group (p = .0149) in the laboratory; and -0.4095 (-8.85%) reduction in DD in the EFT group compared with a + 0.2619 (+5.64%) increase in the CET group (p = .011) at home. Working memory (measured by Backwards Corsi and Digit Span) was found to moderate the effects of EFT on some measures of DD. EFT did not change measures from the food purchase task or a food ad libitum procedure.

CONCLUSIONS

Results show that EFT decreases DD in and out of the laboratory and supports the further exploration of EFT as an intervention for prediabetes and related chronic diseases.

CLINICAL TRIAL REGISTRATION

NCT03664726.