157 research outputs found

    Validation of Acute Myocardial Infarction (AMI) in the FDA’s Mini-Sentinel Distributed Database

    Get PDF
    The Food and Drug Administration’s (FDA) Mini-Sentinel is a pilot program that aims to conduct active surveillance to detect and refine safety signals that emerge for marketed medical products. The purpose of this Mini-Sentinel AMI Validation project was to: (a) develop and design an abstraction and adjudication process to use when full text medical record review is required to confirm a coded diagnosis; and (b) to test this approach by validating a code algorithm for acute myocardial infarction (AMI)

    Laser Guide Stars for Extremely Large Telescopes: Efficient Shack-Hartmann Wavefront Sensor Design using Weighted center-of-gravity algorithm

    Full text link
    Over the last few years increasing consideration has been given to the study of Laser Guide Stars (LGS) for the measurement of the disturbance introduced by the atmosphere in optical and near-infrared astronomical observations from the ground. A possible method for the generation of a LGS is the excitation of the Sodium layer in the upper atmosphere at approximately 90 km of altitude. Since the Sodium layer is approximately 10 km thick, the artificial reference source looks elongated, especially when observed from the edge of a large aperture. The spot elongation strongly limits the performance of the most common wavefront sensors. The centroiding accuracy in a Shack-Hartmann wavefront sensor, for instance, decreases proportionally to the elongation (in a photon noise dominated regime). To compensate for this effect a straightforward solution is to increase the laser power, i.e. to increase the number of detected photons per subaperture. The scope of the work presented in this paper is twofold: an analysis of the performance of the Weighted Center of Gravity algorithm for centroiding with elongated spots and the determination of the required number of photons to achieve a certain average wavefront error over the telescope aperture.Comment: 10 pages, 14 figure

    A Mouse Model of Huntington’s Disease Shows Altered Ultrastructure of Transverse Tubules in Skeletal Muscle Fibers

    Get PDF
    Huntington’s disease (HD) is a fatal and progressive condition with severe debilitating motor defects and muscle weakness. Although classically recognized as a neurodegenerative disorder, there is increasing evidence of cell autonomous toxicity in skeletal muscle. We recently demonstrated that skeletal muscle fibers from the R6/2 model mouse of HD have a decrease in specific membrane capacitance, suggesting a loss of transverse tubule (t-tubule) membrane in R6/2 muscle. A previous report also indicated that Cav1.1 current was reduced in R6/2 skeletal muscle, suggesting defects in excitation–contraction (EC) coupling. Thus, we hypothesized that a loss and/or disruption of the skeletal muscle t-tubule system contributes to changes in EC coupling in R6/2 skeletal muscle. We used live-cell imaging with multiphoton confocal microscopy and transmission electron microscopy to assess the t-tubule architecture in late-stage R6/2 muscle and found no significant differences in the t-tubule system density, regularity, or integrity. However, electron microscopy images revealed that the cross-sectional area of t-tubules at the triad were 25% smaller in R6/2 compared with age-matched control skeletal muscle. Computer simulation revealed that the resulting decrease in the R6/2 t-tubule luminal conductance contributed to, but did not fully explain, the reduced R6/2 membrane capacitance. Analyses of bridging integrator-1 (Bin1), which plays a primary role in t-tubule formation, revealed decreased Bin1 protein levels and aberrant splicing of Bin1 mRNA in R6/2 muscle. Additionally, the distance between the t-tubule and sarcoplasmic reticulum was wider in R6/2 compared with control muscle, which was associated with a decrease in junctophilin 1 and 2 mRNA levels. Altogether, these findings can help explain dysregulated EC coupling and motor impairment in Huntington’s disease

    Effect of increasing the time between slurry application and first rainfall event on phosphorus concentrations in runoff

    Get PDF
    Publication history: Accepted - 26 May 2021; Published online - 12 August 2021.Minimizing slurry phosphorus (P) losses in runoff requires careful management in the context of both soil P surpluses and changing patterns in rainfall. Increasing the time interval between slurry application and the first rainstorm event is known to reduce P loss in runoff although the risk period for elevated P concentrations in runoff can extend for weeks. This study investigated the impact of increasing the time interval between slurry application and first rainstorm event on P concentrations in runoff. Simulated rainfall (40 mm h−1) was applied at 2, 4, 10, 18, 30 and 49 days after dairy slurry was surface-applied to a grassland sward in Ireland. Increasing time to runoff resulted in a decrease in dissolved reactive P concentrations from 5.0 to 1.0 mg P L−1 and a P signal in runoff for 18 days. Beyond 18 days, elevated P concentrations were observed in runoff collected from natural rainfall that preceded the day 49 rainstorm event. A published surface phosphorus and runoff model (SurPhos) was used to understand the slurry P dynamics controlling P interactions with runoff. Dissolved reactive P in runoff was predicted with accuracy by SurPhos, R2 = .89. The SurPhos model implied thatslurry P mineralization occurred during the experimental period that resulted in a small spike in P concentrations beyond the defined risk period. This study shows that the experimental data have the potential to be extrapolated to different weather scenarios using SurPhos and could test when and where slurry P could be most safely spread.Open access funding provided by IReL. WOA Institution: University College Dublin Blended DEAL: IReL

    Air Quality Modeling for the Urban Jackson, Mississippi Region Using a High Resolution WRF/Chem Model

    Get PDF
    In this study, an attempt was made to simulate the air quality with reference to ozone over the Jackson (Mississippi) region using an online WRF/Chem (Weather Research and Forecasting–Chemistry) model. The WRF/Chem model has the advantages of the integration of the meteorological and chemistry modules with the same computational grid and same physical parameterizations and includes the feedback between the atmospheric chemistry and physical processes. The model was designed to have three nested domains with the inner-most domain covering the study region with a resolution of 1 km. The model was integrated for 48 hours continuously starting from 0000 UTC of 6 June 2006 and the evolution of surface ozone and other precursor pollutants were analyzed. The model simulated atmospheric flow fields and distributions of NO2 and O3 were evaluated for each of the three different time periods. The GIS based spatial distribution maps for ozone, its precursors NO, NO2, CO and HONO and the back trajectories indicate that all the mobile sources in Jackson, Ridgeland and Madison contributing significantly for their formation. The present study demonstrates the applicability of WRF/Chem model to generate quantitative information at high spatial and temporal resolution for the development of decision support systems for air quality regulatory agencies and health administrators

    Acquisition of pneumococci specific effector and regulatory Cd4+ T cells localising within human upper respiratory-tract mucosal lymphoid tissue

    Get PDF
    The upper respiratory tract mucosa is the location for commensal Streptococcus (S.) pneumoniae colonization and therefore represents a major site of contact between host and bacteria. The CD4(+) T cell response to pneumococcus is increasingly recognised as an important mediator of immunity that protects against invasive disease, with data suggesting a critical role for Th17 cells in mucosal clearance. By assessing CD4 T cell proliferative responses we demonstrate age-related sequestration of Th1 and Th17 CD4(+) T cells reactive to pneumococcal protein antigens within mucosal lymphoid tissue. CD25(hi) T cell depletion and utilisation of pneumococcal specific MHCII tetramers revealed the presence of antigen specific Tregs that utilised CTLA-4 and PDL-1 surface molecules to suppress these responses. The balance between mucosal effector and regulatory CD4(+) T cell immunity is likely to be critical to pneumococcal commensalism and the prevention of unwanted pathology associated with carriage. However, if dysregulated, such responses may render the host more susceptible to invasive pneumococcal infection and adversely affect the successful implementation of both polysaccharide-conjugate and novel protein-based pneumococcal vaccines

    Enhanced feedback interventions to promote evidence-based blood transfusion guidance and reduce unnecessary use of blood components:The AFFINITIE research programme including two cluster factorial RCTs

    Get PDF
    Background: Blood transfusion is a common but costly treatment. Repeated national audits in the UK suggest that up to one-fifth of transfusions are unnecessary when judged against recommendations for good clinical practice. Audit and feedback seeks to improve patient care and outcomes by comparing clinical care against explicit standards. It is widely used internationally in quality improvement. Audit and feedback generally has modest but variable effects on patient care. A considerable scope exists to improve the impact that audit and feedback has, particularly through head-to-head trials comparing different ways of delivering feedback. Objectives: The AFFINITIE (Development & Evaluation of Audit and Feedback INterventions to Increase evidence-based Transfusion practIcE) programme aimed to design and evaluate enhanced feedback interventions, within a national blood transfusion audit programme, to promote evidence-based guidance and reduce the unnecessary use of blood components. We developed, piloted and refined two feedback interventions, ‘enhanced content’ and ‘enhanced follow-on’ (workstream 1), evaluated the effectiveness and cost-effectiveness of the two feedback interventions compared with standard feedback practice (workstream 2), examined intervention fidelity and contextual influences (workstream 3) and developed general implementation recommendations and tools for other audit and feedback programmes (workstream 4). Design: Interviews, observations and documentary analysis in four purposively sampled hospitals explored contemporary practice and opportunities for strengthening feedback. We developed two interventions: ‘enhanced content’, to improve the clarity and utility of feedback reports, and ‘enhanced follow-on’, to help hospital staff with action-planning (workstream 1). We conducted two linked 2 × 2 factorial cross-sectional cluster-randomised trials within transfusion audits for major surgery and haematological oncology, respectively (workstream 2). We randomised hospital clusters (the organisational level at which hospital transfusion teams operate) to enhanced or standard content or enhanced or standard follow-on. Outcome assessment was masked to assignment. Decision-analytic modelling evaluated the costs, benefits and cost-effectiveness of the feedback interventions in both trials from the perspective of the NHS. A parallel process evaluation used semistructured interviews, documentary analyses and web analytics to assess the fidelity of delivery, receipt and enactment and to identify contextual influences (workstream 3). We explored ways of improving the impact of national audits with their representatives (workstream 4). Setting and participants: All NHS hospital trusts and health boards participating in the National Comparative Audit of Blood Transfusions were invited to take part. Among 189 hospital trusts and health boards screened, 152 hospital clusters participated in the surgical audit. Among 187 hospital trusts and health boards screened, 141 hospital clusters participated in the haematology audit. Interventions: ‘Enhanced content’ aimed to ensure that the content and format of feedback reports were consistent with behaviour change theory and evidence. ‘Enhanced follow-on’ comprised a web-based toolkit and telephone support to facilitate local dissemination, planning and response to feedback. Main outcome measures: Proportions of acceptable transfusions, based on existing evidence and guidance and algorithmically derived from national audit data. Data sources: Trial primary outcomes were derived from manually collected, patient-level audit data. Secondary outcomes included routinely collected data for blood transfusion. Results: With regard to the transfusions in the major surgery audit, 135 (89%) hospital clusters participated from 152 invited. We randomised 69 and 66 clusters to enhanced and standard content, respectively, and 68 and 67 clusters to enhanced and standard follow-on, respectively. We analysed a total of 2222 patient outcomes at 12 months in 54 and 58 (enhanced and standard content, respectively) and 54 and 58 (enhanced and standard follow-on, respectively) hospital clusters. With regard to the haematology audit, 134 hospital clusters (95%) participated from 141 invited. We randomised 66 and 68 clusters to enhanced and standard content, respectively, and 67 clusters to both enhanced and standard follow-on. We analysed a total of 3859 patient outcomes at 12 months in 61 and 61 (enhanced and standard content, respectively) and 63 and 59 (enhanced and standard follow-on) hospital clusters. We found no effect of either of the enhanced feedback interventions in either trial across all outcomes. Incremental enhanced intervention costs ranged from £18 to £248 per site. The enhanced feedback interventions were dominated by the standard intervention in cost-effectiveness analyses. The interventions were delivered as designed and intended, but subsequent local engagement was low. Although the enhancements were generally acceptable, doubts about the credibility of the blood transfusion audits undermined the case for change. Limitations: Limitations included the number of participating clusters; loss to follow-up of trial clusters, reducing statistical power and validity; incomplete audit and cost data contributing to outcome measures; participant self-selection; reporting; missing data related to additional staff activity generated in response to receiving feedback; and recall biases in the process evaluation interviews. Conclusions: The enhanced feedback interventions were acceptable to recipients but were more costly and no more effective than standard feedback in reducing unnecessary use of blood components, and, therefore, should not be recommended on economic grounds. Future work: We have demonstrated the feasibility of embedding ambitious large-scale rigorous research within national audit programmes. Further head-to-head comparisons of different feedback interventions are needed in these programmes to identify cost-effective ways of increasing the impact of the interventions

    Does a local financial incentive scheme reduce inequalities in the delivery of clinical care in a socially deprived community? A longitudinal data analysis.

    Get PDF
    BACKGROUND: Socioeconomic deprivation is associated with inequalities in health care and outcomes. Despite concerns that the Quality and Outcomes Framework pay-for-performance scheme in the UK would exacerbate inequalities in primary care delivery, gaps closed over time. Local schemes were promoted as a means of improving clinical engagement by addressing local health priorities. We evaluated equity in achievement of target indicators and practice income for one local scheme. METHODS: We undertook a longitudinal survey over four years of routinely recorded clinical data for all 83 primary care practices. Sixteen indicators were developed that covered five local clinical and public health priorities: weight management; alcohol consumption; learning disabilities; osteoporosis; and chlamydia screening. Clinical indicators were logit transformed from a percentage achievement scale and modelled allowing for clustering of repeated measures within practices. This enabled our study of target achievements over time with respect to deprivation. Practice income was also explored. RESULTS: Higher practice deprivation was associated with poorer performance for five indicators: alcohol use registration (OR 0.97; 95 % confidence interval 0.96,0.99); recorded chlamydia test result (OR 0.97; 0.94,0.99); osteoporosis registration (OR 0.98; 0.97,0.99); registration of repeat prednisolone prescription (OR 0.98; 0.96,0.99); and prednisolone registration with record of dual energy X-ray absorptiometry (DEXA) scan/referral (OR 0.92; 0.86,0.97); practices in deprived areas performed better for one indicator (registration of osteoporotic fragility fracture (OR 1.26; 1.04,1.51). The deprivation-achievement gap widened for one indicator (registered females aged 65-74 with a fracture referred for a DEXA scan; OR 0.97; 0.95,0.99). Two other indicators indicated a similar trend over two years before being withdrawn (registration of fragility fracture and over-75 s with a fragility fracture assessed and treated for osteoporosis risk). For one indicator the deprivation-achievement gap reduced over time (repeat prednisolone prescription (OR 1.01; 1.01,1.01). Larger practices and those serving more affluent areas earned more income per patient than smaller practices and those serving more deprived areas (t = -3.99; p =0.0001). CONCLUSIONS: Any gaps in achievement between practices were modest but mostly sustained or widened over the duration of the scheme. Given that financial rewards may not reflect the amount of work undertaken by practices serving more deprived patients, future pay-for-performance schemes also need to address fairness of rewards in relation to workload

    An innovative telemedicine knowledge translation program to improve quality of care in intensive care units: protocol for a cluster randomized pragmatic trial

    Get PDF
    Abstract Background There are challenges to timely adoption of, and ongoing adherence to, evidence-based practices known to improve patient care in the intensive care unit (ICU). Quality improvement initiatives using a collaborative network approach may increase the use of such practices. Our objective is to evaluate the effectiveness of a novel knowledge translation program for increasing the proportion of patients who appropriately receive the following six evidence-based care practices: venous thromboembolism prophylaxis; ventilator-associated pneumonia prevention; spontaneous breathing trials; catheter-related bloodstream infection prevention; decubitus ulcer prevention; and early enteral nutrition. Methods and design We will conduct a pragmatic cluster randomized active control trial in 15 community ICUs and one academic ICU in Ontario, Canada. The intervention is a multifaceted videoconferenced educational and problem-solving forum to organize knowledge translation strategies, including comparative audit and feedback, educational sessions from content experts, and dissemination of algorithms. Fifteen individual ICUs (clusters) will be randomized to receive quality improvement interventions targeting one of the best practices during each of six study phases. Each phase lasts four months during the first study year and three months during the second. At the end of each study phase, ICUs are assigned to an intervention for a best practice not yet received according to a random schedule. The primary analysis will use patient-level process-of-care data to measure the intervention's effect on rates of adoption and adherence of each best practice in the targeted ICU clusters versus controls. Discussion This study design evaluates a new system for knowledge translation and quality improvement across six common ICU problems. All participating ICUs receive quality improvement initiatives during every study phase, improving buy-in. This study design could be considered for other quality improvement interventions and in other care settings. Trial Registration This trial is registered with http://www.clinicaltrials.gov (ID #: NCT00332982

    From theory to practice: improving the impact of health services research

    Get PDF
    BACKGROUND: While significant strides have been made in health research, the incorporation of research evidence into healthcare decision-making has been marginal. The purpose of this paper is to provide an overview of how the utility of health services research can be improved through the use of theory. Integrating theory into health services research can improve research methodology and encourage stronger collaboration with decision-makers. DISCUSSION: Recognizing the importance of theory calls for new expectations in the practice of health services research. These include: the formation of interdisciplinary research teams; broadening the training for those who will practice health services research; and supportive organizational conditions that promote collaboration between researchers and decision makers. Further, funding bodies can provide a significant role in guiding and supporting the use of theory in the practice of health services research. SUMMARY: Institutions and researchers should incorporate the use of theory if health services research is to fulfill its potential for improving the delivery of health care
    • …
    corecore