Can present biasedness explain early onset of diabetes and subsequent disease progression? Exploring causal inference by linking survey and register data

Do time preferences predict diabetes outcomes? A combined survey and register-based study

Identifying determinants of heterogeneity in health outcomes continues to be a focus in the health economic literature. In this study, we analyze whether time preferences predict health outcomes in individuals with type 1 diabetes (T1D) who use insulin pump therapy to manage their condition. We collect data on time preferences using a hypothetical matching task and estimate aggregate as well as individual-level discounting parameters using the exponential, hyperbolic, and quasi-hyperbolic discounting models. These parameters are then regressed against essential diabetes-related health outcomes obtained from registries and medical records, including glycemic control, kidney function, BMI, and number of hospital contacts. Our analyses indicate that all three discounting models fit the data equally well. Except for hospital contacts, we find robust evidence that impatience, as reflected by higher discounting, predicts worse health outcomes. Additionally, present bias is associated with worse kidney function. Our findings suggest that time preferences can explain some of the heterogeneity in health among individuals with T1D and call for increased attention on the role of time preferences in the design of disease management programs for individuals with chronic conditions.

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.

Get active now or later? The association between physical activity and risk and time preferences

Despite the well-established link between physical activity and positive health outcomes, much of the world's population remains inactive. Many people don't invest in health behaviours, such as physical activity, in the present, despite the long-term benefits of this. The aim of this study was to assess the relationship between physical activity levels and risk and time preferences in university students. A maximum likelihood model was used to jointly estimate risk and time preferences (elicited in an incentivised choice experiment), and to examine the relationship between these preferences and self-reported physical activity. Physically inactive people discounted the future significantly more than physically active people did. Physically active people made slightly more risky choices in our risk attitude task, although this directional relationship was not statistically significant. The link between time preferences and physical activity suggests that further research on behavioural strategies such as commitment devices, nudging or temptation bundling may be helpful in increasing physical activity for individuals who discount the future in favour of more immediate benefits.

Risk and time preferences in individuals with lifestyle-related and non-lifestyle-related cardiovascular diseases: a pilot study

OBJECTIVES

To (1) pilot a study of behavioural characterisation based on risk and time preferences in clinically well-characterised individuals, (2) assess the distribution of preferences in this population and (3) explore differences in preferences between individuals with 'lifestyle-related' (LS) and 'non-lifestyle-related' (NLS) cardiovascular diseases.

DESIGN

Cross-sectional study with an economic online experiment to collect risk and time preferences, a detailed clinical characterisation and a sociodemographic and lifestyle survey. A definition of LS and NLS groups was developed.

SETTING

Specialist outpatient clinics of the clinic for cardiology and pneumology of the University Hospital Düsseldorf and patients from a cardiology practice in Düsseldorf.

PARTICIPANTS

A total of 74 individuals with cardiovascular diseases.

OUTCOMES

Risk and time preferences.

RESULTS

The implementation of the study process, including participant recruitment and data collection, ran smoothly. The medical checklist, the survey and the time preference instrument were well received. However, the conceptual understanding of the risk preference instrument resulted in inconsistent choices for many participants (47%). The remaining individuals were more risk averse (27%) than risk seeking (16%) and risk neutral (10%). Individuals in our sample were also more impatient (49%) than patient (42%). The participant classification showed that 65% belonged to the LS group, 19% to the NLS group and 16% could not be assigned (unclear allocation to lifestyle (ULS) group). Excluding the ULS group, we show that individuals in the LS group were more risk seeking, and unexpectedly, more patient than those in the NLS group.

CONCLUSIONS

The process of the pilot study and its results can be used as a basis for the design of the main study. The differences in risk and time preferences between the LS and NLS groups provide us with a novel hypothesis for unhealthy behaviours: individuals never give up a bad habit, they simply postpone the latter, which can be tested alongside other additional research questions.

(No) time to be healthy: Optimal policy with time and monetary investments in health

Time is often an important ingredient of a healthy lifestyle. Starting from this observation, this paper studies optimal public policy concerned with promoting healthy choices taking into account both monetary and time investments in health. Individuals tend to underestimate the importance of their health while making decisions, which makes their investments too low compared to the first-best. While the decentralization of the first-best requires personalized subsidies on both time and monetary investments, this may be problematic due to informational issues. In a second-best world where individual productivities and time investments are publicly unobservable, whereas monetary investments are observable in an anonymous way, the paper considers a policy with a non-linear income tax and a linear subsidy on monetary health investments. If there are no incentive concerns, all other things equal, monetary investments complementary (substitutable) to time investments should be subsidized more (less) than those independent of time use. The addition of incentive concerns demonstrates that optimal subsidization of monetary health investments is less straightforward than one might think. Overall, the time ingredient in the production of health does play a role in the optimal policy design, affecting not only the subsidy on monetary health investments but also the income taxation.

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.

Differential methylation in CD44 and SEC23A is associated with time preference in older individuals

Time preference is a measure used to ascertain the level of which individuals prefer smaller, immediate rewards over larger, delayed rewards. We explored how an individual's time preference associates with their epigenetic profile. Time preferences were ascertained by asking participants of the Northern Ireland COhort for the Longitudinal study of Ageing to make a series of choices between two hypothetical income scenarios. From these, eight 'time preference' categories were derived, ranging from "patient" to "impatient" on an ordinal scale. The Infinium High Density Methylation Assay, MethylationEPIC (Illumina) was used to evaluate the status of 862,927 CpGs. Time preference and DNA methylation data were obtained for 1648 individuals. Four analyses were conducted, assessing the methylation patterns at single site resolution between patient and impatient individuals using two adjustment models. In this discovery cohort analysis, two CpG sites were identified with significantly different levels of methylation (p < 9 × 10^-8) between the individuals allocated to the patient group and the remaining population following adjustment for covariates; cg08845621 within CD44 and cg18127619 within SEC23A. Neither of these genes have previously been linked to time preference. Epigenetic modifications have not previously been linked to time preference using a population cohort but they may represent important biomarkers of accumulated, complex determinants of this trait. Further analysis is warranted of both the top-ranked results and of DNA methylation as an important link between measurable biomarkers and health behaviours.

Doctor decision making with time inconsistent patients

Non-adherence to treatments is prevalent. The aim of this paper is to model how doctors should adapt their medical treatment decisions if non-adherence is due to present-bias in the patient population, and to test the predictions of this model in a lab experiment. Under certain conditions, a rational doctor should adapt to non-adherence by choosing a treatment all patients complete (though less effective) when the probability of a patient being present-biased is sufficiently large. This is explored in a lab experiment where we test whether students in the doctor role adapt their behaviour as they learn about the distribution of non-adherence (due to present bias) in the patient population over the rounds of the experiment. We test the model prediction when we align individual incentives with the goal of maximising overall patient welfare. The results show that, on average, participants adapt to non-adherence as they learn about the probability of non-adherence (due to present-bias). However, a proportion of participants do not adapt to the optimal choice. The rate of adaptation was similar for the first 5 rounds under both individual incentives and salary. However, participants continued to adapt after round 5 under individual incentives whilst adaptation plateaued under salary. The adaptation to non-adherence may indicate that adherence can be improved by providing doctors with information about the probability of non-adherence (due to present-bias) in their patients.

An Intuitive Risk Communication Tool to Enhance Patient-Provider Partnership in Diabetes Consultation

INTRODUCTION

This technology report introduces an innovative risk communication tool developed to support providers in communicating diabetes-related risks more intuitively to people with type 2 diabetes mellitus (T2DM).

METHODS

The development process involved three main steps: (1) selecting the content and format of the risk message; (2) developing a digital interface; and (3) assessing the usability and usefulness of the tool with clinicians through validated questionnaires.

RESULTS

The tool calculates personalized risk information based on a validated simulation model (United Kingdom Prospective Diabetes Study Outcomes Model 2) and delivers it using more intuitive risk formats, such as "effective heart age" to convey cardiovascular risks. Clinicians reported high scores for the usability and usefulness of the tool, making its adoption in routine care promising.

CONCLUSIONS

Despite increased use of risk calculators in clinical care, this is the first time that such a tool has been developed in the diabetes area. Further studies are needed to confirm the benefits of using this tool on behavioral and health outcomes in T2DM populations.

HIV, risk, and time preferences: Evidence from a general population sample in Lesotho

Identifying individuals most at risk of HIV infection is a priority for policymakers. Apart from specific groups, however, little is known about how to identify those at high risk in the population. Research suggests that attitudes toward risk and time preferences may influence risky sexual behavior, but no studies have so far investigated the interplay between risk attitudes, time preference, and HIV infection. We collect data on risk and time preferences using hypothetical games (multiple price list method) at baseline and data on HIV status at baseline (2010) and endline (2012) allowing us to calculate incidence rate over a 2-year period among 675 participants, males and females 18-32 years old in Lesotho. We find robust evidence of a statistically significant positive associations between HIV incidence and prevalence and risk-loving attitudes, while the associations with risky behaviors and time preferences are not statistically significant. A measure of attitude toward risk, relatively easy to administer to individuals in a survey, is thus associated with future HIV status. This is an important finding for policymakers and suggests the importance of targeting HIV prevention programs to risk-loving individuals and therefore improving program efficiency.

Is time preference and present bias associated with the decision to start, quit or maintain physical activity over time?

Aim

It is commonly observed that individuals transition into and out of physical activity behaviours over time. A better understanding of the determinants of these transitions is important in order to develop effective interventions. Our focus is on examining the role of time preference and present bias (how present or future oriented individuals are) in the decision to start, quit and maintain physical activity over time.

Subject and methods

We examine changes in different types of physical activity participation over time, allowing us to distinguish between physical activity initiation versus maintenance. We use data from the National Longitudinal Survey of Youth 1979 (NLSY79).

Results

We show that present bias impacts maintenance but not initiation of physical activity behaviour. The time preference rate impacts maintenance of strengthening exercise in men only.

Conclusion

The results of our study suggest that interventions aimed at overcoming present bias, such as commitment devices in the form of deposit contracts, may be effective in maintaining physical activity but not initiating physical activity.

Do parental preferences predict engagement in child health programs?

We evaluate the role of behavioral attributes in predicting engagement in an intervention program. Distinct from the previous studies, we investigate how parental preferences influence their engagement behavior in a health program when the targeted outcomes relate to the health of their children, as opposed to their own. We use an artifactual field experiment where the participants were former parent enrollees in a child health management program in Australia. Our findings suggest that parents' time preference and risk tolerance are robust predictors of engagement, measured by program attendance. Attendance is positively associated with patience and risk tolerance in the health domain, after controlling for a host of personality traits and socioeconomic factors. By improving our understanding of the behavioral risk factors for attrition, these findings offer important insights for enhancing participant engagement in intervention programs that are beset with the problem of high attrition.

The link between health and economic preferences: Evidence from 22 OECD countries

We study the link between health status and economic preferences using survey data from 22 Organisation for Economic Co-operation and Development (OECD) countries. We hypothesize that there is a relationship between poor health and the preferences that people hold, and therefore their choices and decisions. We find that individuals with a limiting health condition are more risk averse and less patient, and that this is true for physical and mental health conditions. The magnitudes of the health gap are approximately 60% and 70% of the gender gap in risk and time preferences, respectively. Importantly, the health gaps are large for males, females, young, old, school dropouts, degree holders, employed, nonemployed, rich, and poor. They also hold for countries with different levels of gross domestic product (GDP), inequality, social expenditure, and disease burden.

Associations between self-management behavior and sociodemographic and disease-related characteristics in elderly people with type 2 diabetes - New results from the population-based KORA studies in Germany

AIMS

Self-management behavior (SMB) is an important aspect in the management of diabetes. This study aimed to identify sociodemographic and disease-related factors associated with good SMB in people with type 2 diabetes (T2D).

METHODS

We used data from 479 people with T2D aged 65 or older from the population-based KORA (Cooperative Health Research in the Area of Augsburg) Health Survey 2016 in Southern Germany. We estimated Poisson and logistic regression models testing the cross-sectional relationship between individual or disease-related characteristics and an established SMB sum index comprising six SMB dimensions stratified according to insulin treatment status.

RESULTS

Mean age in the sample was 75 and mean diabetes duration was 13 years. The overall level of SMB was low. Higher SMB index scores were associated with higher age, treatment with insulin, participation in a diabetes education program, and, for people with insulin treatment, with a BMI below 30 kg/m². Single item analyses generally supported these findings.

CONCLUSIONS

SMB in people with T2D needs to be improved with efficient interventions. Targeting obese individuals and those at an early stage of the disease with low-barrier, regular education or self-management programs may be a preferred strategy.

The effect of regulatory focus and time preference on the dual process of physical activity: A cross-sectional study among nurses

AIMS

To examine the dual process of physical activity adoption among nurses and its relationships with two personal orientations-regulatory focus-the tendency to focus on promotion (vs. prevention) goals and time preference as measured by delay discounting: the tendency to overvalue immediate rewards over long-term ones.

BACKGROUND

The dual process theory suggests that both conscious and non-conscious processes influence the adoption of physical activity. However, the role of regulatory focus and time preference in this process was not yet examined.

DESIGN

A cross-sectional online survey among 143 nurses during August-November 2017.

METHODS

Validated measures were used to estimate physical activity habit strength (a non-conscious process) and intention, planning and behaviour control (conscious processes), physical activity level, regulatory focus and time preference. Multivariable ordered logit and logistic models were specified to examine determinants of both processes.

RESULTS

Promotion focus was positively associated with having a strong habit of physical activity among nurses with moderate-to-low activity levels, but it was negatively associated with habit for active nurses. As for time preference, higher delay discounting was negatively associated with nurses' conscious intention to adopt physical activity and with their action planning.

CONCLUSION

Promotion focus and time preference are associated with both conscious and non-conscious processes of physical activity adoption among nurses and should be considered in future health promotion interventions targeted to this population.

IMPACT

Promotion focus and time preference have a significant role in this dual process. Enhancing physical activity of health providers by adjusting the intervention to personal orientations may improve public health.

Time preferences, diabetes self-management behaviours and outcomes: a systematic review

AIM

Time preferences, i.e. individuals' degree of patience/impatience in intertemporal choice, have been found to be associated with suboptimal health behaviours and health outcomes such as smoking, physical inactivity, unhealthy food intake and obesity. In this systematic review, we aimed to synthesise reported associations between time preferences, diabetes self-management behaviours, including use of diabetes technology, and outcomes.

METHODS

We searched MEDLINE, EMBASE, PsycINFO, CINAHL, EconLit and all databases in the Web of Science Core Collection. Peer-reviewed studies of people with diabetes that included at least one diabetes-related behaviour or outcome and a measure of time preferences were included. Non-English language studies were excluded.

RESULTS

A total of 961 records were identified, of which 12 articles were included. Three studies analysed both time-consistent and time-inconsistent preferences, three studies solely analysed time-inconsistent preferences and six studies did not explicitly define a time preference model. Measured outcomes across studies included self-care activities, such as medication-taking, exercising and eating a healthy diet, and biomedical outcomes, such as HbA_1c and diabetes-related complications. There were 10 cross-sectional studies and two panel-data studies. No studies explicitly analysed the relationship between time preferences and diabetes technology use.

CONCLUSIONS

Associations between measures of time preferences, diabetes self-management behaviours and clinical outcomes exist. Higher discount rates determined by both time-consistent and time-inconsistent models predict less diabetes-related self-care and worse outcomes. These findings may add to explanations of the observed variation in diabetes-related health and provide new insights for tailoring interventions and policies aimed at improving diabetes self-management.

Association between time preference, present-bias and physical activity: implications for designing behavior change interventions

BACKGROUND

The decision to initiate or maintain a healthy habit, such as physical activity involves a trade-off between a short-term cost, such as time and effort, which are commonly identified as barriers to physical activity, and a long-term health benefit. Research suggests that individual time preference may be associated with unhealthy behaviors. However, empirical evidence of this for physical activity is scant. This study investigated the relationship between time preference and physical activity, and how this might influence behavior change.

METHODS

Employees (n = 176; mean age 42.2 years) who participated in a physical activity intervention were invited to take part in a behavioral economic field experiment. Two economic experiments, using multiple price lists and monetary trade-off tables involving real money choices, were conducted face-to-face with participants to measure the two components of time preference, namely present-bias and discount rate. Together with individual risk preferences, these three variables were jointly estimated by maximum likelihood. These three parameters were expressed as a linear function of the levels of physical activity while controlling for socio-demographic variables within the same maximum likelihood framework.

RESULTS

Those who were present-biased and who had higher discount rates did significantly less physical activity than their patient and non present-biased counterparts. A 3% lower discount rate and 1.14 unit decrement in the present-bias parameter was associated with a 30 min increase of physical activity per week. This negative association was more significant for certain sub-groups, such as younger and married adults and those with higher staff grade and those who have children. Participants who dropped out of the study earlier were more present-biased.

CONCLUSIONS

Results demonstrated that discount rate and present-biasedness have a significant impact on physical activity levels. Such concepts have been largely overlooked and underutilized in physical activity interventions. Promising implications include 1) utilizing individuals' time preferences to better target interventions; 2) taking account of time preferences in the intervention design; 3) interventions attempting to correct for present-biasedness.

Time preference, outcome expectancy, and self-management in patients with type 2 diabetes

BACKGROUND

Patient self-management is crucial to prevent complications and mortality in type 2 diabetes. From an economic perspective, time preference predicts short-sighted decision making and thus might help to explain non-adherence to self-anagement recommendations. However, recent studies on this association have shown mixed results.

PURPOSE

In this study, we tested whether the combination of time preference and outcome expectancy can improve the predictions of self-management behavior.

PATIENTS AND METHODS

Data from 665 patients with type 2 diabetes were obtained from the cross-sectional KORA (Cooperative Health Research in the Region of Augsburg) GEFU 4 study. Time preference and outcome expectancy were measured by one question each, which were answered on a 4-point Likert scale. Their association with six self-managing behaviors was tested in logistic and linear regression analyses. Likewise, we examined the association between self-management and the interaction of outcome expectancy and time preference.

RESULTS

A high time preference was associated with a significantly lower sum of self-management behaviors (β=-0.29, 95% CI [-0.54, -0.04]). Higher outcome expectancy was associated with a higher self-management score (β=0.21, 95% CI [-0.03, 0.45]). The interaction model showed that low time preference was only associated with better self-management when combined with a high outcome expectancy (β=0.05, 95% CI [-0.28, 0.39] vs β=0.27, 95% CI [-0.09, 0.63]).

CONCLUSION

Time preference and outcome expectancy are interrelated predictors of patient self-management and could be used to identify and to intervene on patients with a potentially poor self-management.

Risk attitudes of people with 'manageable' chronic disease: An analysis under prospect theory

Health promotion interventions can be improved using methods from behavioural economics to identify and target specific decision-making biases at the individual level. In this context, prospect theory provides a suitable framework within which decision-making processes can be operationalised. Focusing on a trade-off between health outcomes and behaviour change incurred by chronic disease management (lifestyle change, or 'self-management'), we are the first to measure the risk attitudes and quantify the full utility function under prospect theory of a patient population. We conducted a series of hypothetical elicitations over health outcomes associated with different self-management behaviours from a population of individuals with or without 'manageable' chronic disease (n = 120). We observed risk aversion in both the gain and the loss domains, as well as significant loss aversion. There seems to be an age effect on risk attitudes in this context, with younger people being on average less risk averse than older people. Our work addresses a need to better understand these decision-making processes, so that behaviour change interventions tailored to specific patient populations can be improved.

Nudging people with Type 2 diabetes towards better self-management through personalized risk communication: A pilot randomized controlled trial in primary care

OBJECTIVES

To assess the feasibility in routine primary care consultation and investigate the effect on risk recall and self-management of a new type of risk communication intervention based on behavioural economics ("nudge-based") for people with Type 2 diabetes mellitus (T2DM).

METHODS

Forty adults with poorly controlled T2DM (HbA1c > 7.5%) were randomized to receive a personalized, nudge-based risk communication intervention (n = 20) or standard care (n = 20). Risk recall and self-management were evaluated at baseline and 12 weeks after the intervention.

RESULTS

Both in terms of feasibility and acceptability, this new risk communication intervention was very satisfactory. Study retention rate after 12 weeks was very high (90%) and participants were highly satisfied with the intervention (4.4 out of 5 on the COMRADE scale). Although not powered to identify significant between-group effects, the intervention significantly improved risk recall after 12 weeks and intentions to make lifestyle changes (dietary behaviour) compared to standard care.

CONCLUSIONS

This pilot study provides the first evidence of the feasibility of implementing in primary care a nudge-based risk communication intervention for people with T2DM. Based on the promising results observed, an adequately powered trial to determine the effectiveness of the intervention on long-term self-management is judged feasible. As a result of this feasibility study, some minor adaptations to the intervention and study methods that would help to facilitate a definitive trial are also reported.