Changes in patient preferences as part of the “Bariatric surgery – Improvement of basic requirements for targeted therapy” (BARIA-DDZ) study

Home Research/Institutes Institute for Health Services Research and Health Economics Junior Research Group Patients' needs and preferences Changes in patient preferences as part of the “Bariatric surgery – Improvement of basic requirements for targeted therapy” (BARIA-DDZ) study

If purely dietary, pharmacological, exercise and/or behavioral therapy measures are not successful, surgical procedures (bariatric surgery) are increasingly used in patients with class II or III obesity. The long-term effect of these procedures on weight reduction and a reduction of cardiovascular risk factors has been proven by study results.”The BARIA-DDZ study analyzes to what extent patients with class I obesity and type 2 diabetes mellitus benefit from this treatment.

Risk and time preferences play a particularly important role in health decisions, such as physical exercise, smoking, alcohol consumption and nutrition. Risk and time preferences can thus explain differences in individual behavior.


The objective of this study is to analyze how a severe change to individual natural circumstances through bariatric surgery is associated with individual preferences and psychological aspects.

In particular, relationships between preferences and clinical parameters, quality of life, clinical patient-relevant outcomes, health-relevant behavior and psychological aspects are studied.


Project Lead and Contact Person


  • Institute for Clinical Diabetology (DDZ)
  •  CINCH –Forschungszentrum für Gesundheitsökonomik Universität Duisburg-Essen


Kleiner strategischer Sondertatbestand


The preferences were recorded before and after the bariatric surgery and at several follow-up examinations up to five years after the surgery.

Physical activity, smoking behavior, alcohol consumption, eating habits, dealing with stress, health locus of control, health-related quality of life and psychological aspects are elicited using a questionnaire.

Risk and time preferences are elicited using an online experiment composed of financially incentivized decision situations. Participants play a number of lotteries with varying probabilities to elicit individual risk preferences. To elicit risk and time preferences, participants make a series of decisions, which vary in the level of payouts and payout times.


2018 – 2020

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