Die Entscheidung von Männern zum PSA-Screening - Eine theoriegeleitete Untersuchung -

Ein Ende der Kontroverse um den Nutzen des PSA-Screenings in der Wissenschaft und im öffentlichen Diskurs ist nicht absehbar. Kürzlich wurde ein fehlerhaftes Studienprotokoll bei der Reevaluation einer gewichtigen Studie aufgedeckt (PLCO), Leitlinien wurden angepasst (U.S. Preventive Services Task...

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Bibliographic Details
Main Author: Becker, Miriam
Contributors: Donner-Banzhoff, Norbert (Prof. Dr. M.H.Sc) (Thesis advisor)
Format: Doctoral Thesis
Published: Philipps-Universität Marburg 2018
Online Access:PDF Full Text
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There is no end in sight to the controversy about the benefits of the PSA screening in re-search and public media. Only recently, an incorrect protocol was discovered during the re-evaluation of a major study, guidelines are adjusted by the U.S. Preventive Services Task Force and a large-scale study is supposed to prove after its estimated completion in 2029 that a risk-adapted early detection can reduce overdiagnosis and overtreatment (PROBASE). Irrespective of these developments, the initial situation always remains the same: the middle-aged man who has to make a decision about the PSA screening. The question of how this decision is made and which components are included in the decision-making process can be analyzed descriptively by the Theory of planned behaviour (TPB) which leads to a deeper understanding of process. It turns out that the behavioral intention is the strongest predictor of the behavior and corresponds with the behavior in all cases. The most probable reason for this correlation seems to be the comparatively easy performance of the test, namely a blood test. The behavioral intention is, in turn, mostly influenced by the attitude, where a distinction is made between an instrumental and an affective component. Both components correlate with each other, sometimes they also oppose each other; however, the evaluation of the two subcategories reveals a generally negative or positive tendency of the attitude. The attitude corresponds with the intention in all cases and closely interacts with the Perceived Behavioral Control (PBC). The PBC is low if a man does not have the confidence to perform the test due to anticipated burdens such as overdiagnosis and overtherapy. It is high if a man considers disadvantages and negative consequences to be unimportant, does not perceive them or tries to avoid them initially by opting for a step-by-step approach. The purpose of this approach is the opportunity to reassess each measure following a bad test result and, hence, to retain control over the process. In principle, what applies is that the higher the Perceived Behavioral Control, the more likely it is for a man to participate in the screening. The influence of the Subjective Norm is less relevant for the decision. Although the majority of men state to have become aware of the test from their social environment and the media, this fact and so-called impressive cases were rarely decisive for the participation in or rejection of the test respectively. However, the description of these cases indicates that the matter is relevant to the men concerned, which is why they are able to remember them. As far as married men are concerned, the influence of wives seems to be more important, which is mostly in favor of the test. A useful expansion of the TPB is the moral norm or values which are highly connected with the Subjective Norm. In most cases, the doctor, who acts as an advisor and representative of knowledge, has a big influence on the decision. It is particularly men who do not question the benefit of the test who anticipate their consulting doctor to have a positive opinion about the PSA screening. Those who are clearly in favor of the test are mostly men who have already participated in a PSA screening in the past. Thus, past behavior and the doctor’s influ-ence are strongly connected, making it diffi-cult to separate these two variables in hind-sight. Due to their huge influence on the decision-making process, we deem it appropriate to include both components to the TPB. Consequently, patients should be in-formed extensively and neutrally be-fore coming into contact with the PSA screening for the first time. Otherwise, a scenario of the following kind might take place: a positive opinion about the PSA screening by a doctor or a tendentious consultation makes the performance of the test more probable. The normal test result makes the patient feel secure and pleased and leads to his repeating the test at certain intervals as a matter of routine. A subsequent consultation and the reception of new information will be influenced by this behavior. This scenario is only likely if the doctor talks about the test or recommends it. The opposite case does not include a PSA screening, which, at best, will have no consequences and, at worst, will have a fatal out-come; a scenario which is not desirable either. Furthermore, the analysis of the results revealed certain patterns of decision-making, which led to a typology of five decision types. The security-oriented type is highly focused on security. He either does not question the information he receives or ignores the negative aspects, which is why he is in favor of the test. The impact-oriented type is highly focused on the disadvantages and potential consequences of a bad test result, which is why he refuses the test. The strategic type is aware of both the disadvantages and advantages of the test and chooses a step-by-step approach. This procedure aims at ensuring his control over potential consequences. The “repeat offender” wants to continue participating in the test; his behavior is influenced by preceding (normal) test results or the doctor’s opinion respectively. The repressing type is torn between advantages and disadvantages on the one hand, as well as moral expectations on the other hand, which is why he wants to postpone the decision to a later point in time. In conclusion, this typology facilitates the evaluation of men’s opinions and needs in the decision-making process with regard to the PSA the PSA-screening.