537 research outputs found

    Bi-local baryon interpolating fields with two flavours

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    We construct bi-local interpolating field operators for baryons consisting of three quarks with two flavors, assuming good isospin symmetry. We use the restrictions following from the Pauli principle to derive relations/identities among the baryon operators with identical quantum numbers. Such relations that follow from the combined spatial, Dirac, color, and isospin Fierz transformations may be called the (total/complete) Fierz identities. These relations reduce the number of independent baryon operators with any given spin and isospin. We also study the Abelian and non-Abelian chiral transformation properties of these fields and place them into baryon chiral multiplets. Thus we derive the independent baryon interpolating fields with given values of spin (Lorentz group representation), chiral symmetry (UL(2)Ă—UR(2)U_L(2) \times U_R(2) group representation) and isospin appropriate for the first angular excited states of the nucleon.Comment: 15 pages, 4 tables, accepted by EPJ

    Assessing measurement invariance of a health-related quality-of-life questionnaire in radiotherapy patients

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    Objective: If the assumption of measurement invariance is not tested, we cannot be sure whether differences observed are due to true differences in health-related quality-of-life (HRQoL), or are measurement artifacts. We aim to investigate this assumption in a sample of heterogeneous cancer patients, focusing on whether age, sex, previous treatment for cancer, and information regarding treatment preferences result in biased HRQoL scores. Methods: 155 cancer patients who were about to begin their first session of radiotherapy were included. HRQoL was measured using the EORTC QLQ-C30. Structural equation modeling was applied to assess whether there was a violation of the assumption of invariance. Results: A satisfactory single construct (Functioning HRQoL) measurement model was found and two violations of invariance were identified. Irrespective of patients’ Functioning HRQoL, older patients reported worse physical functioning and patients who had received treatment prior to radiotherapy reported worse emotional functioning than we would otherwise expect. Conclusions: In the present study, accounting for measurement bias lead to a substantial improvement in the overall fit of the model. By ignoring the bias, we would have concluded that the model fit was unsatisfactory. The findings underline the importance of investigating measurement invariance in scales designed for heterogeneous samples

    Baryon Tri-local Interpolating Fields

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    We systematically investigate tri-local (non-local) three-quark baryon fields with U_L(2)*U_R(2) chiral symmetry, according to their Lorentz and isospin (flavor) group representations. We note that they can also be called as "nucleon wave functions" due to this full non-locality. We study their chiral transformation properties and find all the possible chiral multiplets consisting J=1/2 and J=3/2 baryon fields. We find that the axial coupling constant |g_A| = 5/3 is only for nucleon fields belonging to the chiral representation (1/2,1)+(1,1/2) which contains both nucleon fields and Delta fields. Moreover, all the nucleon fields belonging to this representation have |g_A| = 5/3.Comment: 8 pages, 3 tables, accepted by EPJ

    A systematic review of physical activity promotion strategies

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    This article was first published in:British Journal of Sports Medicine:1996:30:84-89We have reviewed randomised controlled trials of physical activity promotion to provide recent and reliable information on the effectiveness of physical activity promotion. Computerised databases and references of references were searched. Experts were contacted and asked for information about existing work. Studies assessed were randomised controlled trials of healthy, free living, adult subjects, where exercise behaviour was the dependent variable. Eleven trials were identified. No United Kingdom based studies were found. Interventions that encourage walking and do not require attendance at a facility are most likely to lead to sustainable increases in overall physical activity. Brisk walking has the greatest potential for increasing overall activity levels of a sedentary population and meeting current public health recommendations. The small number of trials limits the strength of any conclusions and highlights the need for more research

    Electronic patient-reported outcomes monitoring during lung cancer chemotherapy: A nested cohort within the PRO-TECT pragmatic trial (AFT-39)

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    Objectives: Patients with lung cancer have high symptom burden and diminished quality of life. Electronic patient-reported outcome (PRO) platforms deliver repeated longitudinal surveys via web or telephone to patients and alert clinicians about concerning symptoms. This study aims to determine feasibility of electronic PRO monitoring in lung cancer patients receiving treatment in community settings. Methods: Adults receiving treatment for advanced or metastatic lung cancer at 26 community sites were invited to participate in a prospective trial of weekly electronic PRO symptom monitoring for 12 months (NCT03249090). Surveys assessing patients’ satisfaction with the electronic PRO system were administered at 3 months. Descriptive statistics were generated for demographics, survey completion rates, symptom occurrence, and provider PRO alert management approaches. Pairwise relationships between symptom items were evaluated using intra-individual repeated-measures correlation coefficients. Results: Lung cancer patients (n = 118) participating in electronic PROs were older (mean 64.4 vs 61.9 years, p = 0.03), had worse performance status (p = 0.002), more comorbidities (p = 0.02), and less technology experience than patients with other cancers. Of delivered weekly PRO surveys over 12 months, 91% were completed. Nearly all (97%) patients reported concerning (i.e., severe or worsening) symptoms during participation, with 33% of surveys including concerning symptoms. Pain was the most frequent and longest lasting symptom and was associated with reduced activity level. More than half of alerts to clinicians for concerning symptoms led to intervention. The majority (87%) would recommend using electronic PRO monitoring to other lung cancer patients. Conclusions: Remote longitudinal weekly monitoring of patients with lung cancer using validated electronic PRO surveys was feasible in a multicenter, community-based pragmatic study. A high symptom burden specific to lung cancer was detected and clinician outreach in response to alerts was frequent, suggesting electronic PROs may be a beneficial strategy for identifying actionable symptoms and allow opportunities to optimize well-being in this population

    Floor and ceiling effects in the EORTC QLQ-C30 Physical Functioning Subscale among patients with advanced or metastatic breast cancer

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    Background: The European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 Physical Functioning subscale is a widely used patient-reported outcome measure that quantifies cancer patients' physical functioning. Strong floor/ceiling effects can affect a scale's sensitivity to change. The aim of this study was to characterize floor/ceiling effects of the physical functioning domain in patients with advanced/metastatic breast cancer enrolled in commercial clinical trials and a community-based trial. Methods: The clinical trial cohort comprised patients from 5 registrational trials submitted to the Food and Drug Administration for review (2010-2017). The community cohort comprised a subgroup of patients from the Alliance Patient Reported Outcomes to Enhance Cancer Treatment (PRO-TECT) trial. The distribution of patient responses to Physical Functioning items and the summed score were assessed at the baseline and 3-month follow-up for both cohorts. Descriptive statistics were used to determine floor/ceiling effects at the item and scale levels. Results: The clinical trial cohort and the community cohort consisted of 2407 and 178 patients, respectively. Twenty-four percent or more of the respondents reported “not at all” for having trouble/needing help with each Physical Functioning item across both cohorts and measurement time points. Fourteen to twenty percent of the patients scored perfectly (100 of 100) on the Physical Functioning subscale summary measure (where higher scores indicated better physical functioning) across both cohorts and time points. Conclusions: Minor floor effects and notable ceiling effects were found at the item and scale levels of the Physical Functioning subscale, regardless of cohort, and this creates some uncertainty about its ability to detect changes in physical functioning among high-functioning patients. Investigators may consider adding additional high-functioning items from the EORTC's item library to more accurately describe the impact of anticancer treatment on patients' physical functioning

    Accuracy of the electronic health record’s problem list in describing multimorbidity in patients with heart failure in the emergency department

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    Patients with heart failure (HF) often suffer from multimorbidity. Rapid assessment of multimorbidity is important for minimizing the risk of harmful drug-disease and drug-drug interactions. We assessed the accuracy of using the electronic health record (EHR) problem list to identify comorbid conditions among patients with chronic HF in the emergency department (ED). A retrospective chart review study was performed on a random sample of 200 patients age ≥65 years with a diagnosis of HF presenting to an academic ED in 2019. We assessed participant chronic conditions using: (1) structured chart review (gold standard) and (2) an EHR-based algorithm using the problem list. Chronic conditions were classified into 37 disease domains using the Agency for Healthcare Research Quality’s Elixhauser Comorbidity Software. For each disease domain, we report the sensitivity, specificity, positive predictive value, and negative predictive of using an EHR-based algorithm. We calculated the intra-class correlation coefficient (ICC) to assess overall agreement on Elixhauser domain count between chart review and problem list. Patients with HF had a mean of 5.4 chronic conditions (SD 2.1) in the chart review and a mean of 4.1 chronic conditions (SD 2.1) in the EHR-based problem list. The five most prevalent domains were uncomplicated hypertension (90%), obesity (42%), chronic pulmonary disease (38%), deficiency anemias (33%), and diabetes with chronic complications (30.5%). The positive predictive value and negative predictive value of using the EHR-based problem list was greater than 90% for 24/37 and 32/37 disease domains, respectively. The EHR-based problem list correctly identified 3.7 domains per patient and misclassified 2.0 domains per patient. Overall, the ICC in comparing Elixhauser domain count was 0.77 (95% CI: 0.71-0.82). The EHR-based problem list captures multimorbidity with moderate-to-good accuracy in patient with HF in the ED
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