991 research outputs found
EFFECTS OF ITEM-LEVEL FEEDBACK ON THE RATINGS PROVIDED BY JUDGES IN A MODIFIED-ANGOFF STANDARD SETTING STUDY
Setting performance standards is a judgmental process involving human opinions and values as well as technical and empirical considerations and although all cut score decisions are by nature arbitrary, they should not be capricious. Establishing a minimum passing standard is the technical expression of a policy decision and the information gained through standard setting studies inform these policy decisions. To this end, it is necessary to conduct robust examinations of methods and techniques commonly applied to standard setting studies in order to better understand issues that may influence policy decisions.
The modified-Angoff method remains one of the most popular methods for setting performance standards in testing and assessment. With this method, is common practice to provide content experts with feedback regarding the item difficulties; however, it is unclear how this feedback affects the ratings and recommendations of content experts. Recent research seems to indicate mixed results, noting that the feedback given to raters may or may not alter their judgments depending on the type of data provided, when the data was provided, and how raters collaborated within groups and between groups. This research seeks to examine issues related to the effects of item-level feedback on the judgment of raters.
The results suggest that the most important factor related to item-level feedback is whether or not a Subject Matter Expert (SME) was able to correctly answer a question. If so, then the SMEs tended to rely on their own inherent sense of item difficulty rather than the data provided, in spite of empirical evidence to the contrary. The results of this research may hold implications for how standard setting studies are conducted with regard to the difficulty and ordering of items, the ability level of content experts invited to participate in these studies, and the types of feedback provided
JPL Ephemeris Tapes E9510, E9511, and E9512
The first issue of JPL Ephemeris Tapes is described. These tapes carry the positions and velocities of the planets and of the Moon, plus nutations and nutation rates in longitude and obliquity, together with second and fourth modified differences, for the interval December 30, 1949, to January 5, 2000
Cuprous Oxide as a Catalyst. II. Adsorption by Cuprous Oxide
In a previous paper3, data were presented which demonstrated that cuprous oxide, prepared by the glucose reduction of a cupric nitrate solution at temperatures below 85°, was an active catalyst for the hydrogenation of furfural to furfuryl alcohol. It was also shown that the cuprous oxide was promoted by the addition of calcium oxide and vanadium tetroxidc. The most active mixture contained these oxides in the ratio Cu2O: V204: CaO: : 1.0: 0.71: 1.4. In order to elucidate the role played by the catalyst in the hydrogenation of furfural, the absorptive capacity of the catalyst for furfural and furfuryl alcohol was investigated. Previous work by Stanerson4 had shown that the catalyst would adsorb hydrogen in an irreversible manner at temperatures above 56° C. The authors found that the adsorption of hydrogen may be complicated by reduction of the cuprous oxide component of the catalyst to metallic copper
Interference measurements of non-Abelian e/4 & Abelian e/2 quasiparticle braiding
The quantum Hall states at filling factors and are expected
to have Abelian charge quasiparticles and non-Abelian charge
quasiparticles. For the first time we report experimental evidence for the
non-Abelian nature of excitations at and examine the fermion parity,
a topological quantum number of an even number of non-Abelian quasiparticles,
by measuring resistance oscillations as a function of magnetic field in
Fabry-P\'erot interferometers using new high purity heterostructures. The phase
of observed oscillations is reproducible and stable over long times
(hours) near and , indicating stability of the fermion parity.
When phase fluctuations are observed, they are predominantly phase flips,
consistent with fermion parity change. We also examine lower-frequency
oscillations attributable to Abelian interference processes in both states.
Taken together, these results constitute new evidence for the non-Abelian
nature of quasiparticles; the observed life-time of their combined
fermion parity further strengthens the case for their utility for topological
quantum computation.Comment: A significantly revised version; 54 double-column pages containing 14
pages of main text + Supplementary Materials. The figures, which include a
number of new figures, are now incorporated into the tex
Fast Collision Course Vectoring
Control Systems Laboratory changed its name to Coordinated Science LaboratoryContract DA-36-039-SC-5669
Prevalence and Practice for Rare Diseases in Primary Care: A National Cross-Sectional Study in the USA
Objectives There are more than 7000 rare diseases in the USA, and they are prevalent in 8% of the population. Due to life-threatening risk and limited therapies, early detection and treatment are critical. The purpose of this study was to explore characteristics of visits for patients with rare diseases seen by primary care physicians (PCPs). Design The study used a cross sectional study using a national representative dataset, the National Ambulatory Medical Care Survey for the years 2012–2014. Setting Primary care setting. Participants Visits to PCPs (n=22 306 representing 354 507 772 office visits to PCPs). Primary outcome measures Prevalence of rare diseases in visits of PCPs was the primary outcome. Bivariate analyses and logistic regression analyses were used to compare patients with rare diseases and those without rare diseases and examined characteristics of PCP visits for rare diseases and practice pattern. Results Among outpatient visits to PCPs, rare diseases account for 1.6% of the visits. The majority of patients with rare diseases were established patients (93.0%) and almost half (49.0%) were enrolled in public insurance programmes. The time spent in visits for rare diseases (22.4 min) and visits for more common diseases (21.3 min) was not significantly different (p=0.09). In an adjusted model controlling for patient characteristics (age, sex, types of insurance, reason for this visit, total number of chronic disease, having a rare disease and established or new patient), patients with rare diseases were 52% more likely to be referred to another provider (OR 1.52, 95% CI, 1.01 to 2.28). Conclusions Visits for rare diseases are uncommon in primary care practice. Future research may help to explain whether this low level of management of rare diseases in primary care practice is consistent with a goal of a broad scope of care
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Predicting Emergency Department “Bouncebacks”: A Retrospective Cohort Analysis
Introduction: The short-term return visit rate among patients discharged from emergency departments (ED) is a quality metric and target for interventions. The ability to accurately identify which patients are more likely to revisit the ED could allow EDs and health systems to develop more focused interventions, but efforts to reduce revisits have not yet found success. Whether patients with a high number of ED visits are at increased risk of a return visit remains underexplored.Methods: This was a population-based, retrospective, cohort study using administrative data from a large physician partnership. We included patients discharged from EDs from 80 hospitals in seven states from July 2014 – June 2016. We performed multivariable logistic regression of short-term return visits on patient, visit, hospital, and community characteristics. The primary outcome was the proportion of patients who had a return visit within 14 days of an index ED visit.Results: Among 6,699,717 index visits, the overall risk of 14-day revisit was 12.6%. Frequent visitors accounted for 18.7% of all visits and 40.2% of all 14-day revisits. Frequent visitor status was associated with the highest odds of a revisit (odds ratio [OR] 3.06; 95% confidence interval [CI], 3.041 – 3.073). Other predictors of revisits were cellulitis (OR 2.131; 95% CI, 2.106 – 2.156), alcohol-related disorders (OR 1.579; 95%CI, 1.548 – 1.610), congestive heart failure (OR 1.175; 95% CI, 1.126 – 1.226), and public insurance (Medicaid OR 1.514; 95% CI, 1.501 – 1.528; Medicare OR 1.601; 95% CI, 1.583 – 1.620).Conclusion: Previous ED use – even a single previous visit – was a stronger predictor of a return visit than any other patient, hospital, or community characteristic. Clinicians should consider previous ED use when considering treatment decisions and risk of return visit, as should stakeholders targeting patients at risk of a return visit
Understanding the Use of Prostate Biopsy Among Men with Limited Life Expectancy in a Statewide Quality Improvement Collaborative
BACKGROUND: The potential harms of a prostate cancer (PCa) diagnosis may outweigh its benefits in elderly men.
OBJECTIVE: To assess the use of prostate biopsy in men with limited life expectancy (LE) within the practices comprising the Michigan Urological Surgery Improvement Collaborative (MUSIC).
DESIGN, SETTING, AND PARTICIPANTS: MUSIC is a consortium of 42 practices and nearly 85% of the urologists in Michigan. From July 2013 to October 2014, clinical data were collected prospectively for all men undergoing prostate biopsy.
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We calculated comorbidity-adjusted LE in men aged ≥66 yr and identified men with(limited LE) undergoing a first biopsy. Our LE calculator was not designed for men agedyr; thus these men were excluded. Multivariable models estimated the proportion of all biopsies performed for men with limited LE in each MUSIC practice, adjusting for differences in patient characteristics. We also evaluated what treatments, if any, these patients received.
RESULTS AND LIMITATIONS: Among 3035 men aged ≥66 yr undergoing initial prostate biopsy, 60% had none of the measured comorbidities. Overall, 547 men (18%) had limited LE. Compared with men with a longer LE, these men had significantly higher prostate-specific antigen levels and abnormal digital rectal examination findings. The adjusted proportion of biopsies performed for men with limited LE ranged from 3.8% to 39% across MUSIC practices (p \u3c 0.001). PCa was diagnosed in 69% of men with limited LE; among this group, 74% received any active treatment. Of these men, 46% had high-grade cancer (Gleason score 8-10).
CONCLUSIONS: Among a large and diverse group of urology practices, nearly 20% of prostate biopsies are performed in men with limited LE. These data provide useful context for quality improvement efforts aimed at optimizing patient selection for prostate biopsy.
PATIENT SUMMARY: In this report, nearly 2 of every 10 men undergoing prostate biopsy had a life expectancy (LE)biopsy
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