Nudging Behavioral Economics into Nephrology Care Delivery Research

CKD is a global health concern, affecting 7.2%–13.4% of the world’s population.¹ Although CKD is largely asymptomatic, the economic and health consequences of kidney disease manifested by cardiovascular disease and kidney failure loom large. A recent Kidney Disease Improving Global Outcomes consensus statement underscored the need for CKD screening coupled with risk stratification and treatment for high-risk persons.² In this context, much attention has been placed on the design and implementation of programs to promote early identification of CKD. Considerably less attention has been placed on what happens after screening and how to ensure that individuals with newly identified markers for poor kidney health engage with the health system and receive needed care.

In this issue of JASN, Fukuma and colleagues explored one strategy to bridge this gap, leveraging the mandatory annual medical screening program in Japan that includes measures of kidney health.³ Fukuma et al. conducted a large three-arm pragmatic randomized controlled trial (pRCT), comparing the impact of two different letters that screening participants received with their results, relative to a “control letter”, on the primary outcome of a completed physician visit within 6 months of screening. Secondary outcomes included changes in eGFR, proteinuria, and blood pressure, all measured during the following year’s medical screening event. Participants could receive a “clinical letter” that provided CKD screening results and information about kidney disease and its associated cardiovascular risk, a “nudge-based letter” that additionally incorporated insights of behavioral economics to motivate scheduling of a physician visit, or a “control letter” without any specific mention of kidney health or the importance of medical follow-up. Among the 4011 participants with abnormal markers of kidney health, 18.9% visited a physician within 6 months, with slightly and equally higher percentages among those receiving the intervention letters compared with control (19.7% “clinical”, 19.7% “nudge” and 15.8% “control”; P=0.04). No differences were noted in one-year changes in eGFR, proteinuria, or blood pressure.

Although disappointing, this study is notable for affirming the importance of kidney disease education and awareness to motivate individual engagement in health and as a novel application of behavioral economics in nephrology. Behavioral economics is a field in which researchers seek to understand and modify behaviors or decisions. Many insights of behavioral economics draw on the dual process theory of cognition, which posits that our brains parse information and make decisions alternately through an intuitive, unconscious “system 1” process and a deliberative, conscious “system 2” process.⁴ Nudge strategies, like the letter tested in the pRCT, seek to stimulate recommended behaviors by anticipating and mitigating system 1 process-driven preferences or biases.⁵ Nudges have been used effectively in many public health and health care contexts, including promoting screening for breast and colorectal cancer,⁶ curbing unhealthy lifestyle risk factors such as tobacco and alcohol use,⁷ and encouraging organ donation⁸ and organ acceptance.⁹ However, to our knowledge, Fukuma and colleagues’ work represents the first large-scale study of applied behavioral economics in CKD management.

The “nudge letter” used by Fukuma et al. to stimulate engagement in care leverages three insights from behavioral economics. The first concept is loss aversion, which holds that individuals are more sensitive to the prospect of losses than a comparable prospect of gains. Accordingly, the letter’s language employs a negative framing, underscoring risks of progressive kidney disease and cardiovascular disease potentially associated with failing to complete a follow-up physician visit. Second, the notion of default bias recognizes the power of inertia in decision-making, often manifested as procrastination. In this case, the “nudge letter” eases the decision-making task for recipients by describing what their next steps would be on the path to scheduling a physician visit. Third, the insight of commitment mechanisms is that when individuals actively affirm that they will do something, they are more likely to follow through. Thus, the “nudge letter” encourages recipients to write down the name of their provider and the follow-up visit date.

Behavioral economics–informed strategies for influencing behavior can range from these subtle, less paternalistic nudges to more conspicuous, more paternalistic “shoves”.¹⁰ Choosing the appropriate level of paternalism for a given intervention is a values-laden concern: while nudges preserve more individual autonomy, they may be less effective in influencing behavior. Fukuma and colleagues do not discuss the potential trade-offs associated with more versus less paternalistic applications of their selected insights from behavioral economics. It is possible that while the “nudge letters” had no additional impact on completion of physician visits compared with “clinical letters” in this study, strategies further along the spectrum toward a shove could have been more successful. Similarly, incorporation of other insights could have enhanced the intervention’s effectiveness. Examples of more forceful strategies and additional concepts from behavioral economics that could be employed in this context—present-biased preferences and certainty-biased preferences—are highlighted in Table 1.

Table 1. - Applications of Behavioral Economics in CKD Screening and Follow-up Care

Insight from Behavioral Economics	Definition	Potential Nudge Strategy	Potential Shove Strategy	Consideration for Individual Autonomy
Loss aversion	Individuals are more sensitive to the prospect of losses than the prospect of comparable gains	Negative framing of educational content on the risks of cardiovascular disease if failing to complete a follow-up physician visit (Fukuma et al. 3 )	Negative framing of expanded educational content on the risks of cardiovascular mortality, financial loss, and increased burden to caregivers if failing to complete a follow-up visit	Strategy may withhold relevant information from decision-makers
Default or “status quo” bias	Preference for current state of affairs and avoiding deviation; inertia in decision-making	Describe the steps to schedule a physician follow-up visit (Fukuma et al. 3 )	Pre-schedule a visit with a local nephrology practice for individuals with screen-positive CKD	Potential conflict with patient's preferences among providers; may decrease providers' scheduling flexibility
Commitment mechanism	Structure to enable active affirmation of intent to follow-through, which itself increases follow-though	Provide space for the individual to write down the name of their provider and follow-up visit date (Fukuma et al. 3 )	Encourage the individual to write down the name of their provider and follow-up visit date using an electronic form that may be viewed by health system professionals (i.e., to increase accountability)	Potential loss of confidentiality and privacy
Present-biased preferences	Individuals tend to “over-discount” distant future outcomes relative to more proximal outcomes	Frame educational content to focus on individual's present day values (e.g., weekly recreational activities, travel) that might be given up if renal replacement is needed	Provide vouchers for public transportation, parking, and other “upfront” costs associated with completing follow-up visit	Financial incentives may disproportionately influence lower-income/lower-wealth decision-makers
Certainty-biased preferences	Individuals are more sensitive to tangible concerns than to abstract concerns	Educational content highlights that kidney disease may progress to kidney failure, which typically entails thrice-weekly dialysis treatment	Educational content makes kidney failure a tangible risk by presenting a typical dialysis patient's weekly calendar or by showing a photograph of a new arteriovenous fistula	Potential oversimplification of information shared with decision-makers

Despite the study’s largely negative results, Fukuma et al. demonstrate that behavioral economics can be applied to nephrology and studied in a robust manner. The pRCT study design is gaining traction in the kidney community,¹¹ and this latest example highlights the potential contribution of this study design to explore how nephrology care is delivered to individuals with screen-positive kidney disease. To achieve success, interventions examined in a pRCT must reflect a keen understanding of the context of health care delivery. Fukuma et al. leveraged a mandatory medical screening program in Japan and, while it was not explicitly stated, also took advantage of Japan’s robust mail delivery system, public transportation and education systems, and availability of public health physicians and clinics. Trial results may have been substantially different in a context where large proportions of participants had limited education and health literacy (and thus could not understand the “nudge letters”), suboptimal access to transportation (thus diluting the impact of guidance on next steps), or inadequate health insurance to pay for a physician visit, as in many US communities. These social determinants of health, which impact individuals’ ability to engage in health care, must be considered thoroughly when designing pRCTs and when extrapolating pRCT findings to other contexts.

Applications of behavioral economics directed toward diverse patients, caregivers, and clinicians can and should be studied in other areas of nephrology. Insights could be incorporated into behavioral interventions that aim to increase patient adherence to kidney-friendly diets, to optimize medication adherence post-transplant, or to encourage completion of pre-emptive vascular access. In parallel, behavioral economics-informed interventions could be explored as tools for optimizing behaviors associated with nephrology care delivery. For example, primary care clinicians could be urged to screen for CKD using commitment mechanisms, and nephrologists could be encouraged to refer more patients for kidney transplant evaluation using a referral default programmed into electronic health records. Moreover, medical and nursing trainees might be encouraged to pursue careers in nephrology by underscoring the tangible benefits of being a nephrology provider (certainty-biased preferences). To ensure any such interventions can be successful and sustainable, however, it will be essential to specify the goals of the intervention and the values of all relevant stakeholders—so as to appropriately balance the intervention’s potential effectiveness with values of individual autonomy—and to understand the context in which the intervention would be deployed.

Disclosures

Tuot reports honoraria from the American Society of Nephrology; and scientific Advisor or membership with National Kidney Foundation Bay Area Medical Advisory Board, BluePath Health eConsult Workgroup. The remaining author has nothing to disclose.

Funding

A. Wilk was supported in part by the National Institute of Diabetes and Digestive and Kidney Diseases grant K01-DK128384.