237 research outputs found

    Assessing sensitivity to change: choosing the appropriate change coefficient

    Get PDF
    The past 20-years have seen the development and evaluation of many health status measures. Unlike the high standards demanded of those who conduct and report clinical intervention trials, the methodological rigor for studies examining the sensitivity to change of health status measures are less demanding. It is likely that the absence of a criterion standard for change in health status contributes to this shortcoming. To increase confidence in the results of these types of studies investigators have often calculated multiple change coefficients for the same patient sample. The purpose of this report is to identify the conflict that arises when multiple change coefficients are applied to the same patient sample. Three families of change coefficients based on different assumptions concerning the sample composition are identified: (1) the sample is homogeneous with respect to change; (2) subgroups of patients who truly change by different amounts exist; (3) individual patients, many of whom truly change by different amounts exist. We present several analyses which illustrate a major conceptual conflict: the signal (a measure\u27s true ability to detect change) for some of these coefficients appears in the noise term (measurement error) of the others. We speculate that this dilemma occurs as a result of insufficient preparatory work such as pilot studies to establish the likely change characteristic of the patient population of interest. Uncertainty in the choice of change coefficient could be overcome by conducting pilot studies to ascertain the likely change characteristic of the population of interest. Once the population\u27s change characteristic is identified, the choice of change coefficient should be clear

    Pain Coping Skills Training for Patients Who Catastrophize About Pain Prior to Knee Arthroplasty: A Multisite Randomized Clinical Trial

    Get PDF
    BACKGROUND: Pain catastrophizing has been identified as a prognostic indicator of poor outcome following knee arthroplasty. Interventions to address pain catastrophizing, to our knowledge, have not been tested in patients undergoing knee arthroplasty. The purpose of this study was to determine whether pain coping skills training in persons with moderate to high pain catastrophizing undergoing knee arthroplasty improves outcomes 12 months postoperatively compared with usual care or arthritis education. METHODS: A multicenter, 3-arm, single-blinded, randomized comparative effectiveness trial was performed involving 5 university-based medical centers in the United States. There were 402 randomized participants. The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain Scale, measured at baseline, 2 months, 6 months, and 12 months following the surgical procedure. RESULTS: Participants were recruited from January 2013 to June 2016. In 402 participants, 66% were women and the mean age of the participants (and standard deviation) was 63.2 ± 8.0 years. Three hundred and forty-six participants (90% of those who underwent a surgical procedure) completed a 12-month follow-up. All 3 treatment groups had large improvements in 12-month WOMAC pain scores with no significant differences (p > 0.05) among the 3 treatment arms. No differences were found between WOMAC pain scores at 12 months for the pain coping skills and arthritis education groups (adjusted mean difference, 0.3 [95% confidence interval (CI), -0.9 to 1.5]) or between the pain coping and usual-care groups (adjusted mean difference, 0.4 [95% CI, -0.7 to 1.5]). Secondary outcomes also showed no significant differences (p > 0.05) among the 3 groups. CONCLUSIONS: Among adults with pain catastrophizing undergoing knee arthroplasty, cognitive behaviorally based pain coping skills training did not confer pain or functional benefit beyond the large improvements achieved with usual surgical and postoperative care. Future research should develop interventions for the approximately 20% of patients undergoing knee arthroplasty who experience persistent function-limiting pain. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence

    The Infrared Imaging Spectrograph (IRIS) for TMT: Data Reduction System

    Get PDF
    IRIS (InfraRed Imaging Spectrograph) is the diffraction-limited first light instrument for the Thirty Meter Telescope (TMT) that consists of a near-infrared (0.84 to 2.4 μ\mum) imager and integral field spectrograph (IFS). The IFS makes use of a lenslet array and slicer for spatial sampling, which will be able to operate in 100's of different modes, including a combination of four plate scales from 4 milliarcseconds (mas) to 50 mas with a large range of filters and gratings. The imager will have a field of view of 34×\times34 arcsec2^{2} with a plate scale of 4 mas with many selectable filters. We present the preliminary design of the data reduction system (DRS) for IRIS that need to address all of these observing modes. Reduction of IRIS data will have unique challenges since it will provide real-time reduction and analysis of the imaging and spectroscopic data during observational sequences, as well as advanced post-processing algorithms. The DRS will support three basic modes of operation of IRIS; reducing data from the imager, the lenslet IFS, and slicer IFS. The DRS will be written in Python, making use of open-source astronomical packages available. In addition to real-time data reduction, the DRS will utilize real-time visualization tools, providing astronomers with up-to-date evaluation of the target acquisition and data quality. The quicklook suite will include visualization tools for 1D, 2D, and 3D raw and reduced images. We discuss the overall requirements of the DRS and visualization tools, as well as necessary calibration data to achieve optimal data quality in order to exploit science cases across all cosmic distance scales.Comment: 13 pages, 2 figures, 6 tables, Proceeding 9913-165 of the SPIE Astronomical Telescopes + Instrumentation 201

    Opioid use prior to knee arthroplasty in patients who catastrophize about their pain: preoperative data from a multisite randomized clinical trial

    Get PDF
    Background: Opioid use rates prior to knee arthroplasty (KA) among people who catastrophize about their pain are unknown. We determined prevalence of opioid use and compared patterns of preoperative opioid use and oral morphine equivalent (OME), a measure of daily opioid dose, across varied geographic sites. We also determined which baseline variables were associated with opioid use and OME. Patients and methods: Preoperative opioid use data described type of opioid, dosage, and frequency among 397 patients scheduled for KA. Demographic, knee-related pain, and psychological distress dimensions were examined to identify variables associated with opioid use and opioid dose (OME). Opioid use prevalence and OME were compared across the four sites. A three-level censored regression determined variables associated with opioid use and OME. Results: The overall opioid use prevalence was 31.7% (95% confidence interval [CI] = 27.0, 36.3) and varied across sites from 15.9% (95% CI = 9.0, 22.8) to 51.2% (95% CI = 40.5, 61.9). After adjustment, patients using opioids were more likely to be younger, African American, and have higher self-efficacy and comorbidity scores (P < 0.05). The only variable independently associated with OME was lower depressive symptoms (P < 0.05). Conclusion: People who catastrophized prior to KA did not demonstrate increased preoperative opioid use based on current evidence, but variation in the prevalence of opioid use across study sites was substantial. Variables associated with opioid use were non-modifiable demographic and comorbidity variables

    Professional Standards for School-Based Behavior Analysts

    Get PDF
    The Professional Standards for School-Based Behavior Analysts are intended to serve as an enhanced foundational layer for behavior analysts working specifically in the context of public school settings. These Professional Standards were developed by a team of behavior analysts with experience working in public schools and feedback was obtained from additional behavior analysts and other education professionals. There are five identified Professional Standard areas including: 1) Ethical & Professional Practice; 2) Collaboration; 3) Systems Capacity Building; 4) Instruction; and 5) Leadership & Policy

    Preclinical single photon emission computed tomography of alpha particle-emitting radium-223

    Get PDF
    Objective: Dose optimization and pharmacokinetic evaluation of α-particle emitting radium-223 dichloride (223RaCl2) by planar γ-camera or single photon emission computed tomography (SPECT) imaging are hampered by the low photon abundance and injected activities. In this study, we demonstrate SPECT of 223Ra using phantoms and small animal in vivo models. Methods: Line phantoms and mice bearing 223Ra were imaged using a dedicated small animal SPECT by detecting the low-energy photon emissions from 223Ra. Localization of the therapeutic agent was verified by whole-body and whole-limb autoradiography and its radiobiological effect confirmed by immunofluorescence. Results: A state-of-the-art commercial small animal SPECT system equipped with a highly sensitive collimator enables collection of sufficient counts for three-dimensional reconstruction at reasonable administered activities and acquisition times. Line sources of 223Ra in both air and in a water scattering phantom gave a line spread function with a full-width-at-half-maximum of 1.45 mm. Early and late-phase imaging of the pharmacokinetics of the radiopharmaceutical were captured. Uptake at sites of active bone remodeling was correlated with DNA damage from the α particle emissions. Conclusions: This work demonstrates the capability to noninvasively define the distribution of 223RaCl2, a recently approved α-particle-emitting radionuclide. This approach allows quantitative assessment of 223Ra distribution and may assist radiation-dose optimization strategies to improve therapeutic response and ultimately to enable personalized treatment planning

    Disentangling trait versus state characteristics of the Pain Catastrophizing Scale and the PHQ-8 Depression Scale

    Get PDF
    Background: Research on the role of trait versus state characteristics of a variety of measures among persons experiencing pain has been a focus for the past few decades. Studying the trait versus state nature of the Pain Catastrophizing Scale (PCS) and the Patient Health Questionnaire (PHQ-8) depression scale would be highly informative given both are commonly measured in pain populations and neither scale has been studied for trait/state contributions. Methods: The PHQ-8 and PCS were obtained on persons undergoing knee arthroplasty at baseline, 2-, 6- and 12-month post-surgery (N = 402). The multi-trait generalization of the latent trait-state model was used to partition trait and state variability in PCS and PHQ-8 item responses simultaneously. A set of variables were used to predict trait catastrophizing and trait depression. Results: For total scores, the latent traits and latent states explain 63.2% (trait = 43.2%; state = 20.0%) and 50.2% (trait = 29.4%; state = 20.8%) of the variability in PCS and PHQ-8, respectively. Patients with a high number of bodily pain sites, high levels of anxiety, young patients and African-American patients had high levels of trait catastrophizing and trait depression. The PCS and the PHQ-8 consist of both enduring trait and dynamic state characteristics, with trait characteristics dominating for both measures. Conclusion: Clinicians and researchers using these scales should not assume the obtained measurements solely reflect either trait- or state-based characteristics. Significance: Clinicians and researchers using the PCS or PHQ-8 scales are measuring both state and trait characteristics and not just trait- or state-based characteristics

    KELT-8b: A highly inflated transiting hot Jupiter and a new technique for extracting high-precision radial velocities from noisy spectra

    Get PDF
    We announce the discovery of a highly inflated transiting hot Jupiter discovered by the KELT-North survey. A global analysis including constraints from isochrones indicates that the V = 10.8 host star (HD 343246) is a mildly evolved, G dwarf with Teff=575455+54T_{\rm eff} = 5754_{-55}^{+54} K, logg=4.0780.054+0.049\log{g} = 4.078_{-0.054}^{+0.049}, [Fe/H]=0.272±0.038[Fe/H] = 0.272\pm0.038, an inferred mass M=1.2110.066+0.078M_{*}=1.211_{-0.066}^{+0.078} M_{\odot}, and radius R=1.670.12+0.14R_{*}=1.67_{-0.12}^{+0.14} R_{\odot}. The planetary companion has mass MP=0.8670.061+0.065M_P = 0.867_{-0.061}^{+0.065} MJM_{J}, radius RP=1.860.16+0.18R_P = 1.86_{-0.16}^{+0.18} RJR_{J}, surface gravity loggP=2.7930.075+0.072\log{g_{P}} = 2.793_{-0.075}^{+0.072}, and density ρP=0.1670.038+0.047\rho_P = 0.167_{-0.038}^{+0.047} g cm3^{-3}. The planet is on a roughly circular orbit with semimajor axis a=0.045710.00084+0.00096a = 0.04571_{-0.00084}^{+0.00096} AU and eccentricity e=0.0350.025+0.050e = 0.035_{-0.025}^{+0.050}. The best-fit linear ephemeris is T0=2456883.4803±0.0007T_0 = 2456883.4803 \pm 0.0007 BJDTDB_{\rm TDB} and P=3.24406±0.00016P = 3.24406 \pm 0.00016 days. This planet is one of the most inflated of all known transiting exoplanets, making it one of the few members of a class of extremely low density, highly-irradiated gas giants. The low stellar logg\log{g} and large implied radius are supported by stellar density constraints from follow-up light curves, plus an evolutionary and space motion analysis. We also develop a new technique to extract high precision radial velocities from noisy spectra that reduces the observing time needed to confirm transiting planet candidates. This planet boasts deep transits of a bright star, a large inferred atmospheric scale height, and a high equilibrium temperature of Teq=167555+61T_{eq}=1675^{+61}_{-55} K, assuming zero albedo and perfect heat redistribution, making it one of the best targets for future atmospheric characterization studies.Comment: Submitted to ApJ, feedback is welcom

    The Early Ultraviolet Light-Curves of Type II Supernovae and the Radii of Their Progenitor Stars

    Full text link
    We present a sample of 34 normal SNe II detected with the Zwicky Transient Facility, with multi-band UV light-curves starting at t4t \leq 4 days after explosion, as well as X-ray detections and upper limits. We characterize the early UV-optical colors and provide prescriptions for empirical host-extinction corrections. We show that the t>2t > 2\,days UV-optical colors and the blackbody evolution of the sample are consistent with the predictions of spherical phase shock-cooling (SC), independently of the presence of `flash ionization" features. We present a framework for fitting SC models which can reproduce the parameters of a set of multi-group simulations without a significant bias up to 20% in radius and velocity. Observations of about half of the SNe II in the sample are well-fit by models with breakout radii <1014<10^{14}\,cm. The other half are typically more luminous, with observations from day 1 onward that are better fit by a model with a large >1014>10^{14}\,cm breakout radius. However, these fits predict an early rise during the first day that is too slow. We suggest these large-breakout events are explosions of stars with an inflated envelope or a confined CSM with a steep density profile, at which breakout occurs. Using the X-ray data, we derive constraints on the extended (1015\sim10^{15} cm) CSM density independent of spectral modeling, and find most SNe II progenitors lose <104Myr1<10^{-4} M_{\odot}\, \rm yr^{-1} a few years before explosion. This provides independent evidence the CSM around many SNe II progenitors is confined. We show that the overall observed breakout radius distribution is skewed to higher radii due to a luminosity bias. We argue that the 6622+11%66^{+11}_{-22}\% of red supergiants (RSG) explode as SNe II with breakout radii consistent with the observed distribution of field RSG, with a tail extending to large radii, likely due to the presence of CSM.Comment: Submitted to ApJ. Comments are welcome at [email protected] or [email protected]
    corecore