335 research outputs found

    Blood Transfusion Errors within a Health System: A Review of Root Cause Analyses

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    IntroductionBlood transfusions are lifesaving treatments which require critical attention to processes and details. If processes are not followed, grievous errors can lead to sentinel events. A review of investigations completed due to reported events will show the error trends associated with systems used throughout the blood transfusion process. MethodsThis study employed root cause analyses (RCAs) within the Veterans Health Administration (VHA) to review the events leading to blood transfusion errors. Data was pulled from the RCA databases within the VA National Center for Patient Safety. The time frame was October 2014 to August 2019. A total of 53 RCAs and aggregated reviews were included in the study. These were reviewed for common themes and gaps present within processes. ResultsThe most common events fell within the categories of incorrect or delayed blood orders, incorrect or lack of patient identification, and wrong blood given. The RCA for each event was reviewed and studied. The RCAs had a crossover of multiple causes; lack of a formal process, communication barriers, and technology barriers were the most frequent. ConclusionThese RCAs express great variation between VHA facilities, such as process created, number of staff reports, and number of RCAs completed. Lack of standard practices nationwide, training barriers, and technology barriers may explain the variation of transfusion errors throughout the VHA. This study brings to light questions about standardization of transfusion protocols. Future study regarding such standardization is necessary to determine its plausibility

    The HIV Care Continuum among Female Sex Workers: A Key Population in Lilongwe, Malawi

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    ObjectiveThe HIV care continuum among female sex workers (FSW), a key population, has not been well characterized, especially within the generalized epidemics of sub-Saharan Africa. This was the first study to characterize the HIV care continuum among FSW in Lilongwe, Malawi.MethodsFrom July through September 2014, we used venue-based sampling to enroll 200 adult FSW in Lilongwe, Malawi into a cross-sectional evaluation assessing HIV care continuum outcomes. Seropositive FSW, identified using HIV rapid testing, received rapid CD4 counts in addition to viral loads using dried blood spots. We calculated proportions of HIV-infected FSW who had history of care, were on ART, and had suppressed viral load and we used Poisson regression to estimate the associations of demographic characteristics and transmission risk behaviors with each outcome.ResultsHIV seroprevalence was 69% (n = 138). Among all FSW the median age was 24 years (IQR: 22–28). Among the 20% who were newly diagnosed and reported previously testing negative, the median time since last HIV test was 11 months (interquartile range: 3–17). The majority (69%) of HIV-infected FSW had a history of HIV care, 52% reported current ART use, and 45% were virally suppressed. Of the FSW who reported current ART use, 86% were virally suppressed. Transmission risk behaviors were not associated with continuum outcomes.ConclusionsFSW in Lilongwe were predominately young and have a high HIV prevalence. Only half of HIV-infected FSW reported current ART use, but the majority of those on ART were virally suppressed. To reduce ongoing transmission and improve health outcomes, increased HIV testing, care engagement, and ART coverage is urgently needed among FSW. Universal testing and treatment strategies for all FSW in Malawi must be strongly considered

    Very Small Array observations of the Sunyaev-Zel'dovich effect in nearby galaxy clusters

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    We present VSA observations (~34GHz) on scales ~20 arcmin towards a complete, X-ray-flux-limited sample of seven clusters at redshift z<0.1. Four have significant SZ detections in the presence of CMB primordial anisotropy. We use a bayesian MCMC method for inference from the VSA data, with X-ray priors on cluster positions and temperatures, and radio priors on sources. We make assumptions of beta-model gas distributions and of hydrostatic equilibrium, to evaluate probability densities for the gas mass and total mass out to r_200. Our combined estimate of the gas fraction is 0.08^{+0.06}_{-0.04}h^{-1} The random errors are poor (note that the errors are higher than would have been obtained with the usual chi-squared method) but the control of bias is good. We have described the MCMC analysis method specifically in terms of SZ but hope the description will be of more general use. We find that the effects of primordial CMB contamination tend to be similar in the estimates of both the gas mass and total mass over our narrow range of angular scales, so that there is little effect of primordials on the gas fraction determination. Using our total mass estimates we find a normalisation of the mass-temperature relation based on the profiles from the VSA cluster pressure maps that is in good agreement with recent M-T determinations from X-ray cluster measurements.Comment: Replaces earlier version. 16 pages, 5 figures, LaTeX. Minor revisions to content, accepted by MNRAS for publicatio

    High sensitivity measurements of the CMB power spectrum with the extended Very Small Array

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    We present deep Ka-band (ν33\nu \approx 33 GHz) observations of the CMB made with the extended Very Small Array (VSA). This configuration produces a naturally weighted synthesized FWHM beamwidth of 11\sim 11 arcmin which covers an \ell-range of 300 to 1500. On these scales, foreground extragalactic sources can be a major source of contamination to the CMB anisotropy. This problem has been alleviated by identifying sources at 15 GHz with the Ryle Telescope and then monitoring these sources at 33 GHz using a single baseline interferometer co-located with the VSA. Sources with flux densities \gtsim 20 mJy at 33 GHz are subtracted from the data. In addition, we calculate a statistical correction for the small residual contribution from weaker sources that are below the detection limit of the survey. The CMB power spectrum corrected for Galactic foregrounds and extragalactic point sources is presented. A total \ell-range of 150-1500 is achieved by combining the complete extended array data with earlier VSA data in a compact configuration. Our resolution of Δ60\Delta \ell \approx 60 allows the first 3 acoustic peaks to be clearly delineated. The is achieved by using mosaiced observations in 7 regions covering a total area of 82 sq. degrees. There is good agreement with WMAP data up to =700\ell=700 where WMAP data run out of resolution. For higher \ell-values out to =1500\ell = 1500, the agreement in power spectrum amplitudes with other experiments is also very good despite differences in frequency and observing technique.Comment: 16 pages. Accepted in MNRAS (minor revisions

    Searching for non-Gaussianity in the VSA data

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    We have tested Very Small Array (VSA) observations of three regions of sky for the presence of non-Gaussianity, using high-order cumulants, Minkowski functionals, a wavelet-based test and a Bayesian joint power spectrum/non-Gaussianity analysis. We find the data from two regions to be consistent with Gaussianity. In the third region, we obtain a 96.7% detection of non-Gaussianity using the wavelet test. We perform simulations to characterise the tests, and conclude that this is consistent with expected residual point source contamination. There is therefore no evidence that this detection is of cosmological origin. Our simulations show that the tests would be sensitive to any residual point sources above the data's source subtraction level of 20 mJy. The tests are also sensitive to cosmic string networks at an rms fluctuation level of 105μK105 \mu K (i.e. equivalent to the best-fit observed value). They are not sensitive to string-induced fluctuations if an equal rms of Gaussian CDM fluctuations is added, thereby reducing the fluctuations due to the strings network to 74μK74 \mu K rms . We especially highlight the usefulness of non-Gaussianity testing in eliminating systematic effects from our data.Comment: Minor corrections; accepted for publication to MNRA

    Estimating the bispectrum of the Very Small Array data

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    We estimate the bispectrum of the Very Small Array data from the compact and extended configuration observations released in December 2002, and compare our results to those obtained from Gaussian simulations. There is a slight excess of large bispectrum values for two individual fields, but this does not appear when the fields are combined. Given our expected level of residual point sources, we do not expect these to be the source of the discrepancy. Using the compact configuration data, we put an upper limit of 5400 on the value of f_NL, the non-linear coupling parameter, at 95 per cent confidence. We test our bispectrum estimator using non-Gaussian simulations with a known bispectrum, and recover the input values.Comment: 17 pages, 16 figures, replaced with version accepted by MNRAS. Primordial bispectrum recalculated and figure 11 change

    CMB observations from the CBI and VSA: A comparison of coincident maps and parameter estimation methods

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    We present coincident observations of the Cosmic Microwave Background (CMB) from the Very Small Array (VSA) and Cosmic Background Imager (CBI) telescopes. The consistency of the full datasets is tested in the map plane and the Fourier plane, prior to the usual compression of CMB data into flat bandpowers. Of the three mosaics observed by each group, two are found to be in excellent agreement. In the third mosaic, there is a 2 sigma discrepancy between the correlation of the data and the level expected from Monte Carlo simulations. This is shown to be consistent with increased phase calibration errors on VSA data during summer observations. We also consider the parameter estimation method of each group. The key difference is the use of the variance window function in place of the bandpower window function, an approximation used by the VSA group. A re-evaluation of the VSA parameter estimates, using bandpower windows, shows that the two methods yield consistent results.Comment: 10 pages, 6 figures. Final version. Accepted for publication in MNRA

    Cosmological parameter estimation using Very Small Array data out to l=1500

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    We estimate cosmological parameters using data obtained by the Very Small Array (VSA) in its extended configuration, in conjunction with a variety of other CMB data and external priors. Within the flat Λ\LambdaCDM model, we find that the inclusion of high resolution data from the VSA modifies the limits on the cosmological parameters as compared to those suggested by WMAP alone, while still remaining compatible with their estimates. We find that Ωbh2=0.02340.0014+0.0012\Omega_{\rm b}h^2=0.0234^{+0.0012}_{-0.0014}, Ωdmh2=0.1110.016+0.014\Omega_{\rm dm}h^2=0.111^{+0.014}_{-0.016}, h=0.730.05+0.09h=0.73^{+0.09}_{-0.05}, nS=0.970.03+0.06n_{\rm S}=0.97^{+0.06}_{-0.03}, 1010AS=233+710^{10}A_{\rm S}=23^{+7}_{-3} and τ=0.140.07+0.14\tau=0.14^{+0.14}_{-0.07} for WMAP and VSA when no external prior is included.On extending the model to include a running spectral index of density fluctuations, we find that the inclusion of VSA data leads to a negative running at a level of more than 95% confidence (nrun=0.069±0.032n_{\rm run}=-0.069\pm 0.032), something which is not significantly changed by the inclusion of a stringent prior on the Hubble constant. Inclusion of prior information from the 2dF galaxy redshift survey reduces the significance of the result by constraining the value of Ωm\Omega_{\rm m}. We discuss the veracity of this result in the context of various systematic effects and also a broken spectral index model. We also constrain the fraction of neutrinos and find that fν<0.087f_{\nu}< 0.087 at 95% confidence which corresponds to mν<0.32eVm_\nu<0.32{\rm eV} when all neutrino masses are the equal. Finally, we consider the global best fit within a general cosmological model with 12 parameters and find consistency with other analyses available in the literature. The evidence for nrun<0n_{\rm run}<0 is only marginal within this model

    Supported self-management for adults with type 2 diabetes and a learning disability (OK-Diabetes): study protocol for a randomised controlled feasibility trial

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    Background: Individuals with a learning disability (LD) are at higher risk of developing type 2 diabetes, but LD is not straightforward to define or identify, especially at the milder end of the spectrum, which makes case finding difficult. While supported self-management of health problems is now established, current material is largely educational and didactic with little that facilitates behavioural change. The interaction between the person with diabetes and others supporting their care is also largely unknown. For these reasons, there is considerable work needed to prepare for a definitive trial. The aim of this paper is to publish the abridged protocol of this preparatory work. Methods/Design: Phase I is a prospective case-finding study (target n = 120 to 350) to identify and characterise potential participants, while developing a standardised supported self-management intervention. Phase II is a randomised feasibility trial (target n = 80) with blinded outcome assessment. Patients identified in Phase I will be interviewed and consented prior to being randomised to (1) standard treatment, or (2) supported self-management. Both arms will also be provided with an ‘easy read’ accessible information resource on managing type 2 diabetes. The intervention will be standardised but delivered flexibly depending on patient need, including components for the participant, a supporter, and shared activities. Outcomes will be (i) robust estimates of eligibility, consent and recruitment rates with refined recruitment procedures; (ii) characterisation of the eligible population; (iii) a standardised intervention with associated written materials, (iv) adherence and negative outcomes measures; (v) preliminary estimates of adherence, acceptability, follow-up and missing data rates, along with refined procedures; and (vi) description of standard treatment. Discussion: Our study will provide important information on the nature of type 2 diabetes in adults with LD living in the community, on the challenges of identifying those with milder LD, and on the possibilities of evaluating a standardised intervention to improve self-management in this population. Trial registration: Current Controlled Trials ISRCTN41897033 (registered 21 January 2013)
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