Medica 2018

••• 7 ••• Innovationen “It is a fundamental assumption in economics that decision-makers welcome information. The more knowledge they have, the better it is,” Nora Szech, holder of the Chair of Political Economy, explains. “If the decision is of fundamental im- portance to one’s own life, how- ever, this is not always true,” the economist continues. As an ex- ample, she mentions patients that may possibly be affected by a seri- ous disease. “They often shy away from the diagnostic test.” To solve this problem, Szech has developed a method that provides the pa- tients with an alternative to the often feared precise tests. Shying away from diagnosis re- duces options of prevention and of adapting life. An example: The incurable hereditary disease Cho- rea Huntington has been predict- able with the help of genetic tests for decades already. If one parent is affected, the descendants have a risk of 50 per cent of being af- fected by the same disease at the age of about 40. The genetic de- fect causes most severe physical and psychic damage, such that the patients will need full-time care after a while. Empirical studies re- veal that patients change their life drastically as soon as they know that they will remain healthy or fall ill. Professional, financial, and fam- ily plans are adapted accordingly. “Still, most risk patients decide against the test,” Szech says. “Peo- ple do not want to live with the bur- den of knowing that the disease will break out,” Nikolaus Schweizer of Tilburg University adds. The rea- son for refusing tests typically is a reaction that anticipates future ex- perience: “If I am 20 years old and get the information that I will fall ill at the age of 40, this will strongly affect my well-being in the next healthy years already,” Szech ex- plains. “Many fear to lose hope.” To cope with this problem, the econo- mist uses findings of behavioural economics and psychology. Ear- lier studies of moral behaviour by Szech focused on the unfavourable effects of diffusion or spreading of responsibility. “Whoever can hide behind others will behave more recklessly and greedily,” she found. When having to choose between winning money or saving the life of a mouse, test persons more often decided in favour of the former option when the decision was made jointly in a group. If the persons were solely responsible and alone, they mostly refused the money and saved the mouse. “Group decisions are based on logics, the decision might have been made by another person in the group.” When fearing a bad diagnosis, however, the power of diffusion can be used positively. This is demonstrated by Schweiz- er’s and Szech’s new test meth- ods: “If, for example, the samples of two risk patients are mixed, the test loses part of its horror.” If the genetic defect does not ex- ist, both patients will be relieved. They will remain healthy and can organize their lives accordingly. They may give birth to children without being afraid of the dis- ease and of passing it on to them. They can choose their job accord- ingly or make old-age provisions. If the genetic defect exists, how- ever, it remains unclear who has the defect or whether both pa- tients have it. “The individual has a chance of 33 per cent of not coming down with Chorea Hun- tington,” Szech explains. Such a result may be worse than the initial situation when the risk of falling ill was 50 per cent, Szech admits. “But there is still good rea- son for hope to remain healthy.” Randomized methods might also help lower the barrier to testing, because many people, according to empirical studies, have a some- what distorted picture of prob- abilities, Schweizer adds. “A clear diagnosis and all-clear signal are very good for the well-being. This is what the new methods offer without the feared risk of learn- ing that the disease will inevitably break out in the future.” According to Szech, tests using mixed blood samples have already been made in many countries, but in a different context. Exam- ples are examinations of donated blood or for the military sector, where diseases were to be exclud- ed in order to save costs. Szech does not see any legal or ethic ob- stacles to such tests in Germany. The deliberately less precise tests can also be carried out for individ- uals when randomizing the evalu- ation of the sample. Medical tests with less fear Mixed blood samples: researchers develop alternative methods to lower the barrier to testing Many people shy away from diagnostic tests. Pool samples might reduce fear. Photo: Patrick Langer, KIT Continued from page 1 medisana.de Hall 15 Booth A23 One App for all devices – your health at a glance. My health in one App – VitaDock+App