1,325 research outputs found
Boosting advice and knowledge sharing among healthcare professionals
Purpose: This study investigates the dynamics of knowledge sharing in
healthcare, exploring some of the factors that are more likely to influence the
evolution of idea sharing and advice seeking in healthcare.
Design/methodology/approach: We engaged 50 pediatricians representing many
subspecialties at a mid-size US children's hospital using a social network
survey to map and measure advice seeking and idea sharing networks. Through the
application of Stochastic Actor-Oriented Models, we compared the structure of
the two networks prior to a leadership program and eight weeks post conclusion.
Findings: Our models indicate that healthcare professionals carefully and
intentionally choose with whom they share ideas and from whom to seek advice.
The process is fluid, non-hierarchical and open to changing partners.
Significant transitivity effects indicate that the processes of knowledge
sharing can be supported by mediation and brokerage. Originality: Hospital
administrators can use this method to assess knowledge-sharing dynamics, design
and evaluate professional development initiatives, and promote new
organizational structures that break down communication silos. Our work
contributes to the literature on knowledge sharing in healthcare by adopting a
social network approach, going beyond the dyadic level, and assessing the
indirect influence of peers' relationships on individual networks
PET/CT Scanner and Bone Marrow Biopsy in Detection of Bone Marrow Involvement in Diffuse Large B-Cell Lymphoma.
Evaluation of bone marrow involvement (BMI) is paramount in diffuse large B-cell lymphoma (DLBCL) for prognostic and therapeutic reasons. PET/CT scanner (PET) is now a routine examination for the staging of DLBCL with prognostic and therapeutic implications. This study evaluates the role of PET for detecting marrow involvement compared to bone marrow biopsy (BMB). This monocentric study included 54 patients diagnosed with DLBCL between 2009 and 2013 and who had FDG PET/CT in a pre-treatment setting. A correlation analysis of the detection of BMI by PET and BMB was performed. A prognostic evaluation of BMI by BMB and/or PET/CT and correlation with an overall 2-year survival were analyzed. PET was more sensitive for the detection of BMI than BMB (92.3% vs. 38.5%). It can be considered a discriminatory Pre-BMB test with a negative predictive value of 97.6%. In addition, BMI by PET had a prognostic value with strong correlation with progression-free survival (PFS) (HR = 3.81; p = 0.013) and overall survival (OS) (HR = 4.12; p = 0.03) while the BMB had not. PET shows superior performance to the BMB for the detection of marrow involvement in DLBCL. It may be considered as the first line examination of bone marrow instead of the biopsy
Dielectric study of the glass transition of PET/PEN blends
An analysis of the glass transition of four materials with similar chemical
structures is performed: PET, PEN and two PET/PEN blends (90/10 and 70/30 w/w).
During the melt processing of the blends transesterification reactions yield
block and random PET/PEN copolymers that act as compatibilizers. The blends
obtained in this way have been characterized by 1H-NMR and DSC. A degree of
randomness of 0.38 and 0.26 has been found for the 90/10 and 70/30 copolymers.
It is shown by DSC that this copolimerization is enough to compatibilize the
blends. The alpha relaxation, the dielectric manifestation of the glass
transition, has been studied by thermally stimulated depolarization currents
(TSDC). The relaxation has been analyzed into its elementary modes by means of
a relaxation map analysis. The activation energies of the modes of the glass
transition do not change significantly between the four materials: in all cases
the modes with a larger contribution have around 3 eV and modes with less than
1 eV are not detected. The change in the pre-exponential factor accounts
entirely for the relaxation time change from material to material, that is
larger as the PEN content increases. The compensation law is fulfilled and
compensation plots converge for high-frequency modes. The polarizability
decreases as the PEN content increases due to the increased stiffness of the
polymer backbone. An analysis of the cooperativity shows that the central modes
of the distribution are the most cooperative while high-frequency modes tend to
behave more as Arrhenius. The low-frequency modes are difficult to study due to
the asymmetry of the distribution of relaxation times. PEN turns out to be the
less cooperative material. It is demonstrated how the parameters obtained from
the dielectric study are able to reproduce calorimetric data from DSC scans and
are, therefore, a valid description of the glass transition.Comment: 22 pages, 13 figure
A simulation model of colorectal cancer surveillance and recurrence
BACKGROUND: Approximately one-third of those treated curatively for colorectal cancer (CRC) will experience recurrence. No evidence-based consensus exists on how best to follow patients after initial treatment to detect asymptomatic recurrence. Here, a new approach for simulating surveillance and recurrence among CRC survivors is outlined, and development and calibration of a simple model applying this approach is described. The model’s ability to predict outcomes for a group of patients under a specified surveillance strategy is validated. METHODS: We developed an individual-based simulation model consisting of two interacting submodels: a continuous-time disease-progression submodel overlain by a discrete-time Markov submodel of surveillance and re-treatment. In the former, some patients develops recurrent disease which probabilistically progresses from detectability to unresectability, and which may produce early symptoms leading to detection independent of surveillance testing. In the latter submodel, patients undergo user-specified surveillance testing regimens. Parameters describing disease progression were preliminarily estimated through calibration to match five-year disease-free survival, overall survival at years 1–5, and proportion of recurring patients undergoing curative salvage surgery from one arm of a published randomized trial. The calibrated model was validated by examining its ability to predict these same outcomes for patients in a different arm of the same trial undergoing less aggressive surveillance. RESULTS: Calibrated parameter values were consistent with generally observed recurrence patterns. Sensitivity analysis suggested probability of curative salvage surgery was most influenced by sensitivity of carcinoembryonic antigen assay and of clinical interview/examination (i.e. scheduled provider visits). In validation, the model accurately predicted overall survival (59% predicted, 58% observed) and five-year disease-free survival (55% predicted, 53% observed), but was less accurate in predicting curative salvage surgery (10% predicted; 6% observed). CONCLUSIONS: Initial validation suggests the feasibility of this approach to modeling alternative surveillance regimens among CRC survivors. Further calibration to individual-level patient data could yield a model useful for predicting outcomes of specific surveillance strategies for risk-based subgroups or for individuals. This approach could be applied toward developing novel, tailored strategies for further clinical study. It has the potential to produce insights which will promote more effective surveillance—leading to higher cure rates for recurrent CRC
Transitions/relaxations in polyester adhesive/PET system
The correlations between the transitions and the dielectric relaxation processes of the oriented poly(ethylene terephthalate) (PET) pre-impregnated of the polyester thermoplastic adhesive have been investigated by differential scanning calorimetry (DSC) and dynamic dielectric spectroscopy (DDS). The thermoplastic polyester adhesive and the oriented PET films have been studied as reference samples. This study evidences that the adhesive chain segments is responsible for the physical structure evolution in the PET-oriented film. The transitions and dielectric relaxation modes’ evolutions in the glass transition region appear characteristic of the interphase between adhesive and PET film, which is discussed in terms of molecular mobility. The storage at room temperature of the adhesive tape involves the heterogeneity of the physical structure, characterized by glass transition dissociation. Thus, the correlation between the transitions and the dielectric relaxation processes evidences a segregation of the amorphous phases. Therefore, the physical structure and the properties of the material have been linked to the chemical characteristics
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Randomized phase 2 trial of monthly vitamin D to prevent respiratory complications in children with sickle cell disease
In sickle cell disease, respiratory infection and asthma may lead to respiratory complications that are a leading cause of morbidity and mortality. Vitamin D has anti-infective and immunomodulatory effects that may decrease the risk for respiratory infections, asthma, and acute chest syndrome. We conducted a randomized double-blind active-controlled clinical trial to determine whether monthly oral vitamin D3 can reduce the rate of respiratory events in children with sickle cell disease. Seventy sickle cell subjects, ages 3-20 years, with baseline records of respiratory events over 1 year before randomization, underwent screening. Sixty-two subjects with 25-hydroxyvitamin D levels of 5-60 ng/mL were randomly assigned to oral vitamin D3 (100 000 IU or 12 000 IU, n = 31 each) under observed administration once monthly for 2 years. The primary outcome was the annual rate of respiratory events (respiratory infection, asthma exacerbation, or acute chest syndrome) ascertained by the use of a validated questionnaire administered biweekly. Analysis included 62 children (mean age of 9.9 years, 52% female, and predominantly with homozygous HbS disease [87%]) with mean baseline 25-hydroxyvitamin D of 14.3 ng/mL. The annual rates of respiratory events at baseline and intervention years 1 and 2 were 4.34 ± 0.35, 4.28 ± 0.36, and 1.49 ± 0.37 (high dose) and 3.91 ± 0.35, 3.34 ± 0.37, and 1.54 ± 0.37 (standard dose), respectively. In pediatric patients with sickle cell disease, 2-year monthly oral vitamin D3 was associated with a >50% reduction in the rate of respiratory illness during the second year (P = .0005), with similar decreases associated with high- and standard-dose treatment
Long-term outcome among men with conservatively treated localised prostate cancer
Optimal management of clinically localised prostate cancer presents unique challenges, because of its highly variable and often indolent natural history. There is an urgent need to predict more accurately its natural history, in order to avoid unnecessary treatment. Medical records of men diagnosed with clinically localised prostate cancer, in the UK, between 1990 and 1996 were reviewed to identify those who were conservatively treated, under age 76 years at the time of pathological diagnosis and had a baseline prostate-specific antigen (PSA) measurement. Diagnostic biopsy specimens were centrally reviewed to assign primary and secondary Gleason grades. The primary end point was death from prostate cancer and multivariate models were constructed to determine its best predictors. A total of 2333 eligible patients were identified. The most important prognostic factors were Gleason score and baseline PSA level. These factors were largely independent and together, contributed substantially more predictive power than either one alone. Clinical stage and extent of disease determined, either from needle biopsy or transurethral resection of the prostate (TURP) chips, provided some additional prognostic information. In conclusion, a model using Gleason score and PSA level identified three subgroups comprising 17, 50, and 33% of the cohort with a 10-year prostate cancer specific mortality of <10, 10–30, and >30%, respectively. This classification is a substantial improvement on previous ones using only Gleason score, but better markers are needed to predict survival more accurately in the intermediate group of patients
Assessing quality of life in men with clinically localized prostate cancer: Development of a new instrument for use in multiple settings
Background : Quality of life in prostate cancer patients with clinically localized disease has become the focus of increasing attention over the past decade. However, few instruments have been developed and validated to assess quality of life specifically in this patient population. Objective : The purpose of this investigation was to create a comprehensive, multi-scale quality of life instrument that can be tailored to the needs of the clinician/investigator in multiple settings. Design , subjects , and measures : Patients diagnosed with clinically localized prostate cancer were mailed a questionnaire consisting of new and previously validated quality of life items and ancillary scales. Data from returned questionnaires were analyzed and used to create a multi-scale instrument that assesses the effects of treatment and disease on urinary, sexual, and bowel domains, supplemented by a scale assessing anxiety over disease course/effectiveness of treatment. The instrument was then mailed to a second sample of prostate cancer patients once and then again two weeks later to assess test–retest reliability. To assess feasibility in clinical settings, the instrument was self-administered to a third patient sample during a urology clinic visit. Results : All scales exhibited good internal consistency and test–retest reliability, convergent and discriminant validity, and significant correlations with disease specific, generic health-related, and global measures of quality of life. Men with greater physiologic impairment reported more limitations in role activities and more bother. Scales were also able to differentiate patients undergoing different therapies. All scales exhibited negligible correlations with a measure of socially desirable responding. Additionally, the instrument proved feasible when used as a self-administered questionnaire in a clinical setting. Conclusions : The current instrument possesses brief multi-item scales that can be successfully self-administered in multiple settings. The instrument is flexible, relatively quick, psychometrically reliable and valid, and permits a more comprehensive assessment of patients' quality of life.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43571/1/11136_2004_Article_282460.pd
A first step towards a global nomogram to predict disease progression for men on active surveillance
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