Part II of this work addresses the use of likelihood ratios for the calculation of a positive predictive value (PPV) and a negative predictive value (NPV) for patient diagnosis. These two values are ...the most useful indices in the application of a diagnostic test in order to make a diagnosis for a patient. Furthermore, the relevance of sample size is also addressed by providing background theory and pertinent tables. These basic topics for assessing the validity of a diagnostic test and for performing appropriate and valid case vs control studies are explained in a simple way for a clinical audience with a working example.
According to evidence-based medicine (EBM), physicians must be able to assess and understand scientific evidence generated from biomedical research. Among the many statistical methods involved in the ...proof of the evidence, an essential area concerns how to select and interpret diagnostic tests to confirm or exclude a diagnosis. Rather surprisingly, these statistical methods are not always correctly reported or satisfactorily explained in some EBM reference books, which leads to misunderstandings and incorrect analyses of published studies in the biomedical literature. In this paper, the authors consider the methodology for performing diagnostic test studies and a correct analysis of the diagnostic test results by explaining it for a clinical audience with a working example.
Introduction
This article points out the design, methods, development and deployment of the international registry promoted by the AutoInflammatory Disease Alliance (AIDA) Network with the aim to ...define and assess paediatric and adult patients with immune-mediated scleritis.
Methods
This registry collects both retrospective and prospective real-world data from patients with non-infectious scleritis through the Research Electronic Data Capture (REDCap) tool and aims to promote knowledge and real-life evidence from patients enrolled worldwide; the registry also allows the collection of standardised data, ensuring the highest levels of security and anonymity of patients’ data and flexibility to change according to scientific acquisitions over time. The communication with other similar registries has been also ensured in order to pursue the sustainability of the project with respect to the adaptation of collected data to the most diverse research projects.
Results
Since the launch of the registry, 99 centres have been involved from 20 countries and four continents. Forty-eight of the centres have already obtained a formal approval from their local ethics committees. At present, the platform counts 259 users (95 principal investigators, 160 site investigators, 2 lead investigators, and 2 data managers); the platform collects baseline and follow-up data using 3683 fields organised into 13 instruments, including patient’s demographics, history, symptoms, trigger or risk factors, therapies and healthcare utilization.
Conclusions
The development of the AIDA International Registry for patients with non-infectious scleritis will allow solid research on this rare condition. Real-world evidence resulting from standardised real-life data will lead to the optimisation of routine clinical and therapeutic management, which are currently limited by the rarity of this ocular inflammatory condition.
To determine whether the rate of acute mastoiditis is rising, specifically as a result of antibiotic-resistant strains of Streptococcus pneumoniae.
A retrospective chart review of all patients with a ...discharge diagnosis of acute mastoiditis between July 1, 1987, and June 30, 1997, was performed at our academic, tertiary-care medical center. There were no interventions, and the main outcome measures included the number of cases of acute or coalescent mastoiditis, stratified by pathogen, per year.
The rate of acute mastoiditis as a proportion of yearly otorhinolaryngology admissions increased linearly over time (P = 0. 024). Pneumococcal-related rates of acute mastoiditis, expressed as a proportion of yearly hospital and otorhinolaryngology admissions, increased linearly over time (P = 0.002, P = 0.002). All but 1 case of pneumococcal mastoiditis during the past 3 years were caused by penicillin-resistant strains.
The emergence of antibiotic-resistant S pneumoniae may be responsible for an increasing rate of acute mastoiditis.
Context.A complex environment exists in the inner few astronomical units of planet-forming disks. High-angular-resolution observa-tions play a key role in our understanding of the disk structure and ...the dynamical processes at work.Aims.In this study we aim to characterize the mid-infrared brightness distribution of the inner disk of the young intermediate-massstar HD 163296 from early VLTI/MATISSE observations taken in theL- andN-bands. We put special emphasis on the detection ofpotential disk asymmetries.Methods.We use simple geometric models to fit the interferometric visibilities and closure phases. Our models include a smoothedring, a flat disk with an inner cavity, and a 2D Gaussian. The models can account for disk inclination and for azimuthal asymmetriesas well. We also perform numerical hydrodynamical simulations of the inner edge of the disk.Results.Our modeling reveals a significant brightness asymmetry in theL-band disk emission. The brightness maximum of the asym-metry is located at the NW part of the disk image, nearly at the position angle of the semimajor axis. The surface brightness ratio inthe azimuthal variation is3.5±0.2. Comparing our result on the location of the asymmetry with other interferometric measurements,we confirm that the morphology of ther<0.3au disk region is time-variable. We propose that this asymmetric structure, located in ornear the inner rim of the dusty disk, orbits the star. To find the physical origin of the asymmetry, we tested a hypothesis where a vortexis created by Rossby wave instability, and we find that a unique large-scale vortex may be compatible with our data. The half-lightradius of theL-band-emitting region is0.33±0.01au, the inclination is52◦+5◦−7◦, and the position angle is143◦±3◦. Our models predictthat a non-negligible fraction of theL-band disk emission originates inside the dust sublimation radius forμm-sized grains. Refractorygrains or large (&10μm-sized) grains could be the origin of this emission.N-band observations may also support a lack of smallsilicate grains in the innermost disk (r.0.6au), in agreement with our findings fromL-band data.
EAQUATE Taylor, P.; Smith, W. L.; Cuomo, V. ...
Bulletin of the American Meteorological Society,
02/2008, Volume:
89, Issue:
2
Journal Article
Peer reviewed
Open access
The international experiment called the European Aqua Thermodynamic Experiment (EAQUATE) was held in September 2004 in Italy and the United Kingdom to validateAquasatellite Atmospheric Infrared ...Sounder (AIRS) radiance measurements and derived products with certain ground-based and airborne systems useful for validating hyperspectral satellite sounding observations. A range of flights over land and marine surfaces were conducted to coincide with overpasses of the AIRS instrument on the Earth Observing SystemAquaplatform. Direct radiance evaluation of AIRS using National Polar-Orbiting Operational Environmental Satellite System (NPOESS) Airborne Sounder Testbed-Interferometer (NAST-I) and the Scanning High-Resolution Infrared Sounder has shown excellent agreement. Comparisons of level-2 retrievals of temperature and water vapor from AIRS and NAST-I validated against high-quality lidar and dropsonde data show that the 1-K/1-km and 10%/1-km requirements for temperature and water vapor (respectively) are generally being met. The EAQUATE campaign has proven the need for synergistic measurements from a range of observing systems for satellite calibration/validation and has paved the way for future calibration/validation activities in support of the Infrared Atmospheric Sounding Interferometer on the European Meteorological Operational platform and Cross-Track Infrared Sounder on the U.S. NPOESS Prepatory Project platform.
This paper presents a study of the atmospheric refraction and its effect on the light coupling efficiency in an instrument using single-mode optical fibres. We show the analytical approach which ...allowed us to assess the need to correct the refraction in J and H bands while observing with an 8-m Unit Telescope. We then developed numerical simulations to go further in calculations. The hypotheses on the instrumental characteristics are those of AMBER (Astronomical Multi BEam combineR), the near-infrared focal beam combiner of the Very Large Telescope Interferometric mode, but most of the conclusions can be generalized to other single-mode instruments. We used the software package caos to take into account the atmospheric turbulence effect after correction by the European Southern Observatory system Multi-Application Curvature Adaptive Optics. The optomechanical study and design of the system correcting the atmospheric refraction on AMBER is then detailed. We showed that the atmospheric refraction becomes predominant over the atmospheric turbulence for some zenith angles z and spectral conditions: for z larger than 30° in J band for example. The study of the optical system showed that it allows to achieve the required instrumental performance in terms of throughput in J and H bands. First observations in J band of a bright star, α Cir star, at more than 30° from zenith clearly showed the gain to control the atmospheric refraction in a single-mode instrument, and validated the operating law.
One of the challenges for evaluating new otoprotective agents for potential benefit in human populations is the availability of an established clinical paradigm with real-world relevance. These ...studies were explicitly designed to develop a real-world digital music exposure that reliably induces temporary threshold shift (TTS) in normal-hearing human subjects.
Thirty-three subjects participated in studies that measured effects of digital music player use on hearing. Subjects selected either rock or pop music, which was then presented at 93 to 95 (n = 10), 98 to 100 (n = 11), or 100 to 102 (n = 12) dBA in-ear exposure level for a period of 4 hr. Audiograms and distortion product otoacoustic emissions (DPOAEs) were measured before and after music exposure. Postmusic tests were initiated 15 min, 1 hr 15 min, 2 hr 15 min, and 3 hr 15 min after the exposure ended. Additional tests were conducted the following day and 1 week later.
Changes in thresholds after the lowest-level exposure were difficult to distinguish from test-retest variability; however, TTS was reliably detected after higher levels of sound exposure. Changes in audiometric thresholds had a "notch" configuration, with the largest changes observed at 4 kHz (mean = 6.3 ± 3.9 dB; range = 0-14 dB). Recovery was largely complete within the first 4 hr postexposure, and all subjects showed complete recovery of both thresholds and DPOAE measures when tested 1 week postexposure.
These data provide insight into the variability of TTS induced by music-player use in a healthy, normal-hearing, young adult population, with music playlist, level, and duration carefully controlled. These data confirm the likelihood of temporary changes in auditory function after digital music-player use. Such data are essential for the development of a human clinical trial protocol that provides a highly powered design for evaluating novel therapeutics in human clinical trials. Care must be taken to fully inform potential subjects in future TTS studies, including protective agent evaluations, that some noise exposures have resulted in neural degeneration in animal models, even when both audiometric thresholds and DPOAE levels returned to pre-exposure values.
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