‘We don’t know for sure’: discussion of uncertainty concerning multigene panel testing during initial cancer genetic consultations

Pre-test counseling about multigene panel testing involves many uncertainties. Ideally, counselees are informed about uncertainties in a way that enables them to make an informed decision about panel testing. It is presently unknown whether and how uncertainty is discussed during initial cancer genetic counseling. We therefore investigated whether and how counselors discuss and address uncertainty, and the extent of shared decision-making (SDM), and explored associations between counselors’ communication and their characteristics in consultations on panel testing for cancer. For this purpose, consultations of counselors discussing a multigene panel with a simulated patient were videotaped. Simulated patients represented a counselee who had had multiple cancer types, according to a script. Before and afterwards, counselors completed a survey. Counselors’ uncertainty expressions, initiating and the framing of expressions, and their verbal responses to scripted uncertainties of the simulated patient were coded by two researchers independently. Coding was done according to a pre-developed coding scheme using The Observer XT software for observational analysis. Additionally, the degree of SDM was assessed by two observers. Correlation and regression analyses were performed to assess associations of communicated uncertainties, responses and the extent of SDM, with counselors’ background characteristics. In total, twenty-nine counselors, including clinical geneticists, genetic counselors, physician assistants-in-training, residents and interns, participated of whom working experience varied between 0 and 25 years. Counselors expressed uncertainties mainly regarding scientific topics (94%) and on their own initiative (95%). Most expressions were framed directly (77%), e.g. We don’t know, and were emotionally neutral (59%; without a positive/negative value). Counselors mainly responded to uncertainties of the simulated patient by explicitly referring to the uncertainty (69%), without providing space for further disclosure (66%). More experienced counselors provided less space to further disclose uncertainty (p < 0.02), and clinical geneticists scored lower on SDM compared with o

Unbiased equations for 95Zr-95Nb chronometry

Formulae are presented for 95Zr-95Nb chronometry of a nuclear event. In particular, they allow for a bias-free calculation of the moment of a nuclear explosion, based solely on a measurement of the produced activity ratio of 95Zr and 95Nb in a finite time interval. Also uncertainty propagation factors are presented, which relate the relative uncertainty on the decay data and activity ratio measurements with the relative uncertainty on the elapsed time. This allows for the calculation of an uncertainty budget, without the need for Monte Carlo simulations. The equations are applied to a set of measurement data and consistency is demonstrated.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Uncertainty propagation in nuclear forensics

Uncertainty propagation formulae are presented for age dating in support of nuclear forensics. The age of radioactive material in this context refers to the time elapsed since a particular radionuclide was chemically separated from its decay product(s). The decay of the parent radionuclide and ingrowth of the daughter nuclide are governed by statistical decay laws. Mathematical equations allow calculation of the age of specific nuclear material through the atom ratio between parent and daughter nuclides, or through the activity ratio provided that the daughter nuclide is also unstable.The derivation of the uncertainty formulae of the age may present some difficulty to the user community and so the exact solutions, some approximations, a graphical representation and their interpretation are presented in this work. Typical nuclides of interest are actinides in the context of non-proliferation commitments. The uncertainty analysis is applied to a set of important parent-daughter pairs and the need for more precise half-life data is examined.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard