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Evaluation of person-level heterogeneity of treatment effects in published multiperson N-of-1 studies: systematic review and reanalysis.
OBJECTIVE:Individual patients with the same condition may respond differently to similar treatments. Our aim is to summarise the reporting of person-level heterogeneity of treatment effects (HTE) in multiperson N-of-1 studies and to examine the evidence for person-level HTE through reanalysis. STUDY DESIGN:Systematic review and reanalysis of multiperson N-of-1 studies. DATA SOURCES:Medline, Cochrane Controlled Trials, EMBASE, Web of Science and review of references through August 2017 for N-of-1 studies published in English. STUDY SELECTION:N-of-1 studies of pharmacological interventions with at least two subjects. DATA SYNTHESIS:Citation screening and data extractions were performed in duplicate. We performed statistical reanalysis testing for person-level HTE on all studies presenting person-level data. RESULTS:We identified 62 multiperson N-of-1 studies with at least two subjects. Statistical tests examining HTE were described in only 13 (21%), of which only two (3%) tested person-level HTE. Only 25 studies (40%) provided person-level data sufficient to reanalyse person-level HTE. Reanalysis using a fixed effect linear model identified statistically significant person-level HTE in 8 of the 13 studies (62%) reporting person-level treatment effects and in 8 of the 14 studies (57%) reporting person-level outcomes. CONCLUSIONS:Our analysis suggests that person-level HTE is common and often substantial. Reviewed studies had incomplete information on person-level treatment effects and their variation. Improved assessment and reporting of person-level treatment effects in multiperson N-of-1 studies are needed
First measurement of discrimination between helium and electron recoils in liquid xenon for low-mass dark matter searches
We report the first measurement of discrimination between low-energy helium
recoils and electron recoils in liquid xenon. This result is relevant to
proposed low-mass dark matter searches which seek to dissolve light target
nuclei in the active volume of liquid-xenon time projection chambers.
Low-energy helium recoils were produced by degrading particles from
Po with a gold foil situated on the cathode of a liquid xenon
time-projection chamber. The resulting population of helium recoil events is
well separated from electron recoils and is also offset from the expected
position of xenon nuclear recoil events.Comment: 4 pages, 3 figure
The Effect of Patientsâ Met Expectations on Consultation Outcomes. A Study with Family Medicine Residents
OBJECTIVES: To know the patientsâ expectations and the fulfillment of these at family medicine consultations by resident doctors and to assess their effect on some consultation outcomes. DESIGN: A prospective cohort study. PARTICIPANTS: Patients attending family medicine consultations held by 38 resident doctors: 1,301 eligible patients, 702 filled in all questionnaires. MEASUREMENTS: Before each visit, the patientsâ expectations about that particular consultation were registered. Right after the visit was over, their perception of several aspects of the communicative interaction with the doctor was measured. Later, patients were interviewed on the phone to know how their expectations had been fulfilled, how satisfied they were about the consultation, how they had followed the doctorâs suggestions, if they were going to seek further care for the same cause later, and the evolution of their clinical problem. Logistic regression was the main analysis used. RESULTS: The most common expectations were the doctor showing interest and listening (30.5%), getting some information about the diagnosis (16.3%), and sharing problems and doubts (11.1%). The rate of main expectations that were met was 76.5%. Satisfaction with the encounter was associated with the clinical evolution [odds ratio (OR) 2.23; confidence interval (CI): 1.32â3.75], and the fulfilling of the patientsâ main or two main expectations was significantly related to all the measured outcomes (satisfaction OR 3.51, CI: 1.73â7.8; adherence OR 1.80, CI: 1.11â2.92; clinical evolution OR 1.54, CI: 1.01â2.35; and seeking further care later OR 0.54, CI:0.36â0.81) CONCLUSIONS: Patients prioritize expectations of a more general sort when they attend primary care consultations and residents fulfill these acceptably. The fulfillment of expectations seems to affect the studied outcomes more than other factors
Observation of activity prior to dielectric breakdown in liquid xenon with the XeBrA experiment
Maintaining the electric fields necessary for the current generation of noble
liquid time projection chambers (TPCs), with drift lengths exceeding one meter,
requires a large negative voltage applied to their cathode. Delivering such
high voltage is associated with an elevated risk of electrostatic discharge and
electroluminescence, which would be detrimental to the performance of the TPC.
The Xenon Breakdown Apparatus (XeBrA) is a five-liter high-voltage test chamber
built to investigate the factors contributing to high voltage breakdown in
noble liquids. Area scaling and surface finish were observed to be the dominant
factors affecting breakdown. In addition, small electrical activity was
frequently observed during high voltage ramps prior to electrostatic discharge.
The position of breakdowns was reconstructed with a system of high-speed
cameras and good agreement with electric field simulations was found. Based on
the results presented in this work, we recommend that the next generation of
TPCs should not withstand fields larger than 20 kV/cm on the electrode
surfaces.Comment: 29 pages, 13 figures; typo in the author list correcte
Psychometric precision in phenotype definition is a useful step in molecular genetic investigation of psychiatric disorders
Affective disorders are highly heritable, but few genetic risk variants have been consistently replicated in molecular genetic association studies. The common method of defining psychiatric phenotypes in molecular genetic research is either a summation of symptom scores or binary threshold score representing the risk of diagnosis. Psychometric latent variable methods can improve the precision of psychiatric phenotypes, especially when the data structure is not straightforward. Using data from the British 1946 birth cohort, we compared summary scores with psychometric modeling based on the General Health Questionnaire (GHQ-28) scale for affective symptoms in an association analysis of 27 candidate genes (249 single-nucleotide polymorphisms (SNPs)). The psychometric method utilized a bi-factor model that partitioned the phenotype variances into five orthogonal latent variable factors, in accordance with the multidimensional data structure of the GHQ-28 involving somatic, social, anxiety and depression domains. Results showed that, compared with the summation approach, the affective symptoms defined by the bi-factor psychometric model had a higher number of associated SNPs of larger effect sizes. These results suggest that psychometrically defined mental health phenotypes can reflect the dimensions of complex phenotypes better than summation scores, and therefore offer a useful approach in genetic association investigations
Search for nucleon decays with EXO-200
A search for instability of nucleons bound in Xe nuclei is reported
with 223 kgyr exposure of Xe in the EXO-200 experiment. Lifetime
limits of 3.3 and 1.9 yrs are established for
nucleon decay to Sb and Te, respectively. These are the most
stringent to date, exceeding the prior decay limits by a factor of 9 and 7,
respectively
Deep Neural Networks for Energy and Position Reconstruction in EXO-200
We apply deep neural networks (DNN) to data from the EXO-200 experiment. In
the studied cases, the DNN is able to reconstruct the relevant parameters -
total energy and position - directly from raw digitized waveforms, with minimal
exceptions. For the first time, the developed algorithms are evaluated on real
detector calibration data. The accuracy of reconstruction either reaches or
exceeds what was achieved by the conventional approaches developed by EXO-200
over the course of the experiment. Most existing DNN approaches to event
reconstruction and classification in particle physics are trained on Monte
Carlo simulated events. Such algorithms are inherently limited by the accuracy
of the simulation. We describe a unique approach that, in an experiment such as
EXO-200, allows to successfully perform certain reconstruction and analysis
tasks by training the network on waveforms from experimental data, either
reducing or eliminating the reliance on the Monte Carlo.Comment: Accepted version. 33 pages, 28 figure
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