[Decisions of the German Federal Joint Committee in situations with insufficient data : Decision-making options for new diagnostic and treatment methods]. / Entscheidungen des Gemeinsamen Bundesausschusses bei unzureichender Datenlage : Entscheidungsoptionen bei neuen Untersuchungs- und Behandlungsmethoden.

BACKGROUND: In accordance with legal requirements, the Federal Joint Committee (German: Gemeinsamer Bundesausschuss, G­BA) decides based on the best available evidence which new diagnostic and treatment methods are reimbursed by statutory health insurance. If the benefit is proven with sufficient certainty, statutory health insurance providers pay for the new method, otherwise a trial study must be conducted. OBJECTIVES: To present the G­BA's decision-making options even in the case of insufficient evidence in the field of urology. MATERIALS AND METHODS: A document search was conducted on the homepage of the G­BA for the decisions about method evaluation and quality assurance in the field of urology of the last 10 years. The respective decisions are presented in the light of the decision options available in each case. RESULTS: Using the example of the debate on low-dose rate brachytherapy for localised prostate cancer, the years-long, ultimately futile, effort to increase the evidence base for an innovative method is presented. CONCLUSION: Compared to the development of guidelines, for example, the G­BA can only make dichotomous yes/no decisions and has to accept the often insufficient evidence situation, or (has to) try to increase the evidence base by initiating its own study. The latter is particularly difficult when specific methods are already established in routine care. A particular challenge is posed by new, especially invasive methods in the hospital sector, which has to be evaluated (benefit assessment) and, if necessary, tested by the G­BA with a trial study. To what extent this will succeed in the future is not yet foreseeable.

Point defects in the NiAl(100) surface.

The stability of various point defects in NiAl(100) has been investigated by first-principles calculations. For Al-rich surfaces, Ni vacancies within the first Al layer are energetically most favourable. For Ni-rich surfaces, so-called double defects, consisting of both Ni-antisite atom in the first Al layer and a Ni vacancy within the second Ni layer, form the configuration of lowest energy, superior to singular Ni antisites. An additional and significant energy gain is found in both cases by mutual lateral interaction of the defects, when they are arranged in the diagonal direction. Respective [Formula: see text] ordered configurations were found as the most stable structures. A 50:50 mixture of both defect types turns out to be even lower in energy than the ideal Al-terminated NiAl(100) surface, proving the latter to be metastable only. This is in line with the often reported inability in experiments to prepare ideal NiAl(100) surfaces.