3,111 research outputs found
Definitions and reliability assessment of elementary ultrasound lesions in giant cell arteritis: a study from the OMERACT Large Vessel Vasculitis Ultrasound Working Group
Objectives: To define the elementary ultrasound (US) lesions in giant cell arteritis (GCA) and to evaluate the reliability of the assessment of US lesions according to these definitions in a web-based reliability exercise. Methods: Potential definitions of normal and abnormal US findings of temporal and extracranial large arteries were retrieved by a systematic literature review. As a subsequent step, a structured Delphi exercise was conducted involving an expert panel of the Outcome Measures in Rheumatology (OMERACT) US Large Vessel Vasculitis Group to agree definitions of normal US appearance and key elementary US lesions of vasculitis of temporal and extracranial large arteries. The reliability of these definitions on normal and abnormal blood vessels was tested on 150 still images and videos in a web-based reliability exercise. Results: Twenty-four experts participated in both Delphi rounds. From originally 25 statements, nine definitions were obtained for normal appearance, vasculitis and arteriosclerosis of cranial and extracranial vessels. The 'halo' and 'compression' signs were the key US lesions in GCA. The reliability of the definitions for normal temporal and axillary arteries, the 'halo' sign and the 'compression' sign was excellent with inter-rater agreements of 91-99% and mean kappa values of 0.83-0.98 for both inter-rater and intra-rater reliabilities of all 25 experts. Conclusions: The 'halo' and the 'compression' signs are regarded as the most important US abnormalities for GCA. The inter-rater and intra-rater agreement of the new OMERACT definitions for US lesions in GCA was excellent
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Upper limits on the strength of periodic gravitational waves from PSR J1939+2134
The first science run of the LIGO and GEO gravitational wave detectors
presented the opportunity to test methods of searching for gravitational waves
from known pulsars. Here we present new direct upper limits on the strength of
waves from the pulsar PSR J1939+2134 using two independent analysis methods,
one in the frequency domain using frequentist statistics and one in the time
domain using Bayesian inference. Both methods show that the strain amplitude at
Earth from this pulsar is less than a few times .Comment: 7 pages, 1 figure, to appear in the Proceedings of the 5th Edoardo
Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July
200
Improving the sensitivity to gravitational-wave sources by modifying the input-output optics of advanced interferometers
We study frequency dependent (FD) input-output schemes for signal-recycling
interferometers, the baseline design of Advanced LIGO and the current
configuration of GEO 600. Complementary to a recent proposal by Harms et al. to
use FD input squeezing and ordinary homodyne detection, we explore a scheme
which uses ordinary squeezed vacuum, but FD readout. Both schemes, which are
sub-optimal among all possible input-output schemes, provide a global noise
suppression by the power squeeze factor, while being realizable by using
detuned Fabry-Perot cavities as input/output filters. At high frequencies, the
two schemes are shown to be equivalent, while at low frequencies our scheme
gives better performance than that of Harms et al., and is nearly fully
optimal. We then study the sensitivity improvement achievable by these schemes
in Advanced LIGO era (with 30-m filter cavities and current estimates of
filter-mirror losses and thermal noise), for neutron star binary inspirals, and
for narrowband GW sources such as low-mass X-ray binaries and known radio
pulsars. Optical losses are shown to be a major obstacle for the actual
implementation of these techniques in Advanced LIGO. On time scales of
third-generation interferometers, like EURO/LIGO-III (~2012), with
kilometer-scale filter cavities, a signal-recycling interferometer with the FD
readout scheme explored in this paper can have performances comparable to
existing proposals. [abridged]Comment: Figs. 9 and 12 corrected; Appendix added for narrowband data analysi
An Indication of Anisotropy in Arrival Directions of Ultra-high-energy Cosmic Rays through Comparison to the Flux Pattern of Extragalactic Gamma-Ray Sources
A new analysis of the data set from the Pierre Auger Observatory provides evidence for anisotropy in the arrivaldirections of ultra-high-energy cosmic rays on an intermediate angular scale, which is indicative of excess arrivalsfrom strong, nearby sources. The data consist of 5514 events above 20 EeV with zenith angles up to 80°recordedbefore 2017 April 30. Sky models have been created for two distinct populations of extragalactic gamma-rayemitters: active galactic nuclei from the second catalog of hard Fermi-LAT sources (2FHL) and starburst galaxiesfrom a sample that was examined with Fermi-LAT. Flux-limited samples, which include all types of galaxies fromthe Swift-BAT and 2MASS surveys, have been investigated for comparison. The sky model of cosmic-ray densityconstructed using each catalog has two free parameters, the fraction of events correlating with astrophysicalobjects, and an angular scale characterizing the clustering of cosmic rays around extragalactic sources. Amaximum-likelihood ratio test is used to evaluate the best values of these parameters and to quantify the strength ofeach model by contrast with isotropy. It is found that the starburst model fits the data better than the hypothesis ofisotropy with a statistical significance of 4.0Ï, the highest value of the test statistic being for energies above39 EeV. The three alternative models are favored against isotropy with 2.7Ï?3.2Ï significance. The origin of theindicated deviation from isotropy is examined and prospects for more sensitive future studies are discussed.Fil: Aab, A.. Radboud University Nijmegen; PaĂses BajosFil: Allekotte, Ingomar. Centro AtĂłmico Bariloche and Instituto Balseiro; ArgentinaFil: Almela, Daniel Alejandro. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Andrada, B.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Bertou, Xavier Pierre Louis. Centro AtĂłmico Bariloche and Instituto Balseiro; ArgentinaFil: Botti, Ana Martina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Cancio, A.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Contreras, F.. Observatorio Pierre Auger; ArgentinaFil: Etchegoyen, Alberto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Figueira, Juan Manuel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Fuster, Alan Ezequiel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Golup, Geraldina Tamara. Centro AtĂłmico Bariloche and Instituto Balseiro; ArgentinaFil: GĂłmez Berisso, M.. Centro AtĂłmico Bariloche and Instituto Balseiro; ArgentinaFil: GĂłmez Vitale, P. F.. Pierre Auger Observatory; ArgentinaFil: GonzĂĄlez, N.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Hampel, Matias Rolf. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Hansen, Patricia Maria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de FĂsica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂsica La Plata; ArgentinaFil: Harari, Diego Dario. Centro AtĂłmico Bariloche and Instituto Balseiro; ArgentinaFil: Holt, E.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Hulsman, Johannes. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Josebachuili Ogando, Mariela Gisele. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Kleinfeller, J.. Pierre Auger Observatory; ArgentinaFil: Lucero, A.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Mollerach, Maria Silvia. Centro AtĂłmico Bariloche and Instituto Balseiro; ArgentinaFil: Melo, Diego Gabriel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: MĂŒller, Ana Laura. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Naranjo, I.. Centro AtĂłmico Bariloche and Instituto Balseiro; ArgentinaFil: Roulet, Esteban. Centro AtĂłmico Bariloche and Instituto Balseiro; ArgentinaFil: Rodriguez Rojo, J.. Pierre Auger Observatory; ArgentinaFil: SĂĄnchez, F.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Santos, E.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Sarmiento Cano, Christian Andres. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Schmidt, D.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Sciutto, Sergio Juan. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de FĂsica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂsica La Plata; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de FĂsica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂsica La Plata; ArgentinaFil: Silli, Gaia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Suarez, F.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Taborda Pulgarin, Oscar Alejandro. Centro AtĂłmico Bariloche and Instituto Balseiro; ArgentinaFil: Wainberg, Oscar Isaac. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Wundheiler, Brian. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: Yushkov, Alexey. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas. Universidad Nacional de San MartĂn. Instituto de TecnologĂa en DetecciĂłn y AstropartĂculas; ArgentinaFil: The Pierre Auger Collaboration. Pierre Auger Observatory; Argentin
Global data on earthworm abundance, biomass, diversity and corresponding environmental properties
Publisher Copyright: © 2021, The Author(s).Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change.Peer reviewe
Effect of surgical experience and spine subspecialty on the reliability of the {AO} Spine Upper Cervical Injury Classification System
OBJECTIVE
The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5â10 years, 10â20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery).
METHODS
A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearsonâs chi-square or Fisherâs exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (Îș) determined the interobserver reliability and intraobserver reproducibility.
RESULTS
The intraobserver reproducibility was substantial for surgeon experience level (< 5 years: 0.74 vs 5â10 years: 0.69 vs 10â20 years: 0.69 vs > 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (< 5 years: 0.67 vs 5â10 years: 0.62 vs 10â20 years: 0.61 vs > 20 years: 0.62), and only surgeons with > 20 years of experience did not have substantial reliability on assessment 2 (< 5 years: 0.62 vs 5â10 years: 0.61 vs 10â20 years: 0.61 vs > 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36).
CONCLUSIONS
The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system
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