Irrational Responses to Risk Preference Questionnaires by Patients with Diabetes with or without Retinopathy and Comparison with Those without Diabetes

Abstract

Purpose

The risk preferences of patients with diabetes have profound effects on the progression of complications. The present study aimed to clarify whether the preferences of patients with diabetes and retinopathy are deliberately risk-seeking or irrational and whether this propensity is specific to those with retinopathy or is also found in patients without retinopathy compared with those without diabetes.

Patients and Methods

A total of 394 patients with diabetes (264 without retinopathy and 130 with retinopathy) and 198 patients without diabetes agreed to participate in this survey. The questions were modified versions of those from the Japan Household Survey on Consumer Preferences and Satisfaction, which sought to determine the participants’ personal socioeconomic status and risk preferences. In the questionnaires, responses were analyzed by determining the participants’ willingness to pay for a lottery ticket and for an insurance policy. Irrational responses were defined as violations of two axioms of the Expected Utility Theory: completeness and transitivity.

Results

The incidence of irrational responses increased with age and was associated with educational level. The incidence of irrational responses was significantly higher in patients with retinopathy than in those without retinopathy after adjusting for age and educational level. There was no significant difference in the incidence of irrational responses between patients with diabetes but without retinopathy and those without diabetes.

Conclusion

The risk-seeking behavior of patients with diabetes and retinopathy was not deliberate but was irrational under uncertainty. Medical professionals should be aware of their patients’ propensity to make irrational decisions, which is an important risk factor for the progression of retinopathy in patients with diabetes regardless of age and educational level.

Keywords:

• behavioral economics
• expected utility theory
• educational level
• cognitive function

Data Sharing Statement

The data that support the findings of this study are stored in the Department of Endocrinology, Diabetes and Metabolism, Graduate School of Medicine, Nippon Medical School, and are available from the corresponding author upon reasonable request.

Ethics Approval and Informed Consent

This study was conducted in accordance with the Declaration of Helsinki. The study was approved by the Internal Review Board of the Ethics Committee of Nippon Medical School (#29-07-803) and Juntendo University Urayasu Hospital. The study participants provided written informed consent for the study contents, purposes, protocols, data confidentiality and anonymity procedures, and publication. The freedom to discontinue the study at any stage was explained and agreed upon.

Acknowledgments

The authors would like to thank Enago (www.enago.jp) for the English language review.

Author Contributions

All authors made substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data, took part in drafting the article or revising it critically for important intellectual content, agreed to submit to the current journal, gave final approval of the version to be published, and agreed to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest.

Additional information

Funding

This study was supported by Grants-in-Aid for scientific research from the Japan Society for the Promotion of Science (KAKENHI) for Research Project #17K08936 (FY 2017-2019).