392 research outputs found

    Accuracy of syndrome definitions based on diagnoses in physician claims

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    <p>Abstract</p> <p>Background</p> <p>Community clinics offer potential for timelier outbreak detection and monitoring than emergency departments. However, the accuracy of syndrome definitions used in surveillance has never been evaluated in community settings. This study's objective was to assess the accuracy of syndrome definitions based on diagnostic codes in physician claims for identifying 5 syndromes (fever, gastrointestinal, neurological, rash, and respiratory including influenza-like illness) in community clinics.</p> <p>Methods</p> <p>We selected a random sample of 3,600 community-based primary care physicians who practiced in the fee-for-service system in the province of Quebec, Canada in 2005-2007. We randomly selected 10 visits per physician from their claims, stratifying on syndrome type and presence, diagnosis, and month. Double-blinded chart reviews were conducted by telephone with consenting physicians to obtain information on patient diagnoses for each sampled visit. The sensitivity, specificity, and positive predictive value (PPV) of physician claims were estimated by comparison to chart review.</p> <p>Results</p> <p>1,098 (30.5%) physicians completed the chart review. A chart entry on the date of the corresponding claim was found for 10,529 (95.9%) visits. The sensitivity of syndrome definitions based on diagnostic codes in physician claims was low, ranging from 0.11 (fever) to 0.44 (respiratory), the specificity was high, and the PPV was moderate to high, ranging from 0.59 (fever) to 0.85 (respiratory). We found that rarely used diagnostic codes had a higher probability of being false-positives, and that more commonly used diagnostic codes had a higher PPV.</p> <p>Conclusions</p> <p>Future research should identify physician, patient, and encounter characteristics associated with the accuracy of diagnostic codes in physician claims. This would enable public health to improve syndromic surveillance, either by focusing on physician claims whose diagnostic code is more likely to be accurate, or by using all physician claims and weighing each according to the likelihood that its diagnostic code is accurate.</p

    Thick collagen-based 3D matrices including growth factors to induce neurite outgrowth

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    Designing synthetic microenvironments for cellular investigations is a very active area of research at the crossroads of cell biology and materials science. The present work describes the design and functionalization of a three-dimensional (3D) culture support dedicated to the study of neurite outgrowth from neural cells. It is based on a dense self-assembled collagen matrix stabilized by 100-nm wide interconnected native fibrils without chemical crosslinking. The matrices were made suitable for cell manipulation and direct observation in confocal microscopy by anchoring them to traditional glass supports with a calibrated thickness of ∼50 μm. The matrix composition can be readily adapted to specific neural cell types, notably by incorporating appropriate neurotrophic growth factors. Both PC-12 and SH-SY5Y lines respond to growth factors (nerve growth factor and brain-derived neurotrophic factor, respectively) impregnated and slowly released from the support. Significant neurite outgrowth is reported for a large proportion of cells, up to 66% for PC12 and 49% for SH-SY5Y. It is also shown that both growth factors can be chemically conjugated (EDC/NHS) throughout the matrix and yield similar proportions of cells with longer neurites (61% and 52%, respectively). Finally, neurite outgrowth was observed over several tens of microns within the 3D matrix, with both diffusing and immobilized growth factors

    Prostate Cancer Postoperative Nomogram Scores and Obesity

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    Nomograms are tools used in clinical practice to predict cancer outcomes and to help make decisions regarding management of disease. Since its conception, utility of the prostate cancer nomogram has more than tripled. Limited information is available on the relation between the nomograms' predicted probabilities and obesity. The purpose of this study was to examine whether the predictions from a validated postoperative prostate cancer nomogram were associated with obesity.We carried out a cross-sectional analysis of 1220 patients who underwent radical prostatectomy (RP) in southern California from 2000 to 2008. Progression-free probabilities (PFPs) were ascertained from the 10-year Kattan postoperative nomogram. Multivariable logistic regression models estimated odds ratios (ORs) and 95% confidence intervals (CIs).In the present study, aggressive prostate cancer (Gleason ≥7), but not advanced stage, was associated with obesity (p = 0.01). After adjusting for age, black race, family history of prostate cancer and current smoking, an inverse association was observed for 10-year progression-free predictions (OR = 0.50; 95% CI = 0.28–0.90) and positive associations were observed for preoperative PSA levels (OR = 1.23; 95% CI = 1.01–1.50) and Gleason >7 (OR = 1.45; 95% CI = 1.11–1.90).Obese RP patients were more likely to have lower PFP values than non-obese patients, suggesting a higher risk of experiencing prostate cancer progression. Identifying men with potentially higher risks due to obesity may improve disease prognosis and treatment decision-making

    Stationary Black Holes: Uniqueness and Beyond

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    The spectrum of known black-hole solutions to the stationary Einstein equations has been steadily increasing, sometimes in unexpected ways. In particular, it has turned out that not all black-hole-equilibrium configurations are characterized by their mass, angular momentum and global charges. Moreover, the high degree of symmetry displayed by vacuum and electro-vacuum black-hole spacetimes ceases to exist in self-gravitating non-linear field theories. This text aims to review some developments in the subject and to discuss them in light of the uniqueness theorem for the Einstein-Maxwell system.Comment: Major update of the original version by Markus Heusler from 1998. Piotr T. Chru\'sciel and Jo\~ao Lopes Costa succeeded to this review's authorship. Significantly restructured and updated all sections; changes are too numerous to be usefully described here. The number of references increased from 186 to 32

    Body mass index is not a predictor of biochemical recurrence after radical prostatectomy in Dutch men diagnosed with prostate cancer

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    Contains fulltext : 95677.pdf (publisher's version ) (Closed access)PURPOSE: To determine the effect of body mass index (BMI) on clinical and pathological characteristics at time of diagnosis and on risk of biochemical recurrence after radical prostatectomy among Dutch men diagnosed with prostate cancer. METHODS: In total, 1,116 prostate cancer patients with known BMI, diagnosed between 2003 and 2006, were identified from the population-based cancer registry held by the Comprehensive Cancer Centre East, The Netherlands. Of these, 504 patients underwent a radical prostatectomy. Patients were categorized as normal weight (BMI /= 30 kg/m(2)). Multivariable proportional hazards regression models, adjusted for age, prediagnostic PSA levels, and pathological characteristics were used to evaluate BMI as a prognostic factor for biochemical recurrence after radical prostatectomy. RESULTS: Overall, clinical and biopsy characteristics did not significantly differ among BMI groups. Pathological characteristics after radical prostatectomy did not significantly differ among BMI groups, except for tumor stage, which was highest in obese patients (P = 0.017). For patients treated with radical prostatectomy, 5-year risk (95% Confidence Intervals) of biochemical recurrence was 30% (23-37%) for normal weight, 32% (25-39%) for overweight, and 25% (9-41%) for obese patients (log rank P = 0.810). BMI was not an independent prognostic factor for biochemical recurrence in multivariable proportional hazards regression analyses (HR 0.99 per kg/m(2), 95% CI: 0.93-1.06). CONCLUSIONS: Compared with non-obese men, pathological tumor stage tended to be higher in obese men. Clinical relevance of this finding is unclear, because BMI was not an independent predictor of biochemical recurrence after radical prostatectomy

    Nurse staffing, direct nursing care hours and patient mortality in Taiwan: the longitudinal analysis of hospital nurse staffing and patient outcome study

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    <p>Abstract</p> <p>Background</p> <p>Studies over the past decades have shown an association between nurse staffing and patient outcomes, however, most of these studies were conducted in the West. Accordingly, the purpose of this study aimed to provide an overview of the research/evidence base which has clarified the relationship between nurse staffing and patient mortality of acute care hospital wards under a universal health insurance system and attempted to provide explanations for some of the phenomena that are unique in Taiwan.</p> <p>Methods</p> <p>Through stratified random sampling, a total of 108 wards selected from 32 hospitals in Taiwan were collected over a consecutive seven month period. The mixed effect logit model was used to explore the relationship between nurse staffing and patient mortality.</p> <p>Results</p> <p>The medians of direct-nursing-care-hour, and nurse manpower were 2.52 h, and 378 persons, respectively. The OR for death between the long direct-nursing-care-hour (> median) group and the short direct-nursing-care-hour (≦median) group was 0.393 (95% CI = [0.245, 0.617]). The OR for death between the high (> median) and the low (≦median) nurse manpower groups was 0.589 (95% CI = [0.381, 0.911]).</p> <p>Conclusions</p> <p>Findings from this study demonstrate an association of nurse staffing and patient mortality and are consistent with findings from similar studies. These findings have policy implications for strengthening the nursing profession, nurse staffing, and the hospital quality associated with nursing. Additional research is necessary to demonstrate adequate nurse staffing ratios of different wards in Taiwan.</p

    A review of elliptical and disc galaxy structure, and modern scaling laws

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    A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their models to describe the radial distribution of stars in `nebulae'. This article reviews the progress since then, providing both an historical perspective and a contemporary review of the stellar structure of bulges, discs and elliptical galaxies. The quantification of galaxy nuclei, such as central mass deficits and excess nuclear light, plus the structure of dark matter halos and cD galaxy envelopes, are discussed. Issues pertaining to spiral galaxies including dust, bulge-to-disc ratios, bulgeless galaxies, bars and the identification of pseudobulges are also reviewed. An array of modern scaling relations involving sizes, luminosities, surface brightnesses and stellar concentrations are presented, many of which are shown to be curved. These 'redshift zero' relations not only quantify the behavior and nature of galaxies in the Universe today, but are the modern benchmark for evolutionary studies of galaxies, whether based on observations, N-body-simulations or semi-analytical modelling. For example, it is shown that some of the recently discovered compact elliptical galaxies at 1.5 < z < 2.5 may be the bulges of modern disc galaxies.Comment: Condensed version (due to Contract) of an invited review article to appear in "Planets, Stars and Stellar Systems"(www.springer.com/astronomy/book/978-90-481-8818-5). 500+ references incl. many somewhat forgotten, pioneer papers. Original submission to Springer: 07-June-201

    Seasonal effects of influenza on mortality in a subtropical city

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    <p>Abstract</p> <p>Background</p> <p>Influenza has been associated with a heavy burden of mortality. In tropical or subtropical regions where influenza viruses circulate in the community most of the year, it is possible that there are seasonal variations in the effects of influenza on mortality, because of periodic changes in environment and host factors as well as the frequent emergence of new antigenically drifted virus strains. In this paper we explored this seasonal effect of influenza.</p> <p>Methods</p> <p>A time-varying coefficient Poisson regression model was fitted to the weekly numbers of mortality of Hong Kong from 1996 to 2002. Excess risks associated with influenza were calculated to assess the seasonal effects of influenza.</p> <p>Results</p> <p>We demonstrated that the effects of influenza were higher in winter and late spring/early summer than other seasons. The two-peak pattern of seasonal effects of influenza was found for cardio-respiratory disease and sub-categories pneumonia and influenza, chronic obstructive pulmonary disease, cerebrovascular diseases and ischemic heart disease as well as for all-cause deaths.</p> <p>Conclusion</p> <p>The results provide insight into the possibility that seasonal factors may have impact on virulence of influenza besides their effects on virus transmission. The results warrant further studies into the mechanisms behind the seasonal effect of influenza.</p

    Barriers and enablers in the management of tuberculosis treatment in Addis Ababa, Ethiopia: a qualitative study

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    Tuberculosis (TB) is an infectious disease which causes about two million deaths each year. In 1993, the World Health Organization (WHO) declared TB to be a “Global Emergency” due to an increasing number of TB cases and a rise in multidrug resistant cases in the developed world. Treatment interruption was considered one of the major challenges. WHO introduced the current TB control program DOTS (directly observed treatment, short course) as the tool to control the disease. To prevent further development of resistance against anti-TB drugs it was decided to observe each patient taking their daily dose of medication. The overall aim of this thesis is to explore how patients and health workers perceive and manage TB symptoms and treatment in a high-endemic and a low-endemic setting in the era of DOT(S). The data is based on fieldwork, including in-depth interviews and focus groups with TB patients and health workers, in Addis Ababa, Ethiopia (2001-2002) and in Oslo/Akershus, Norway (2007-2008). We found that people’s interpretation and management of TB symptoms is influenced by cultural, social and economic factors. TB was, in both contexts, associated with poverty, and subsequently with a disease that affects certain countries or certain segments of a population. TB was viewed as a severe disease in both contexts, but there was variation between individuals to what extent one considered oneself as a likely victim. In the absence of circumstantial causes, such as poverty, patients in a lowendemic setting like Norway, found it difficult to understand why they had developed the disease. There was scarce knowledge about the fact that the disease could be latent. Awareness of early symptoms, such as persistent cough, was low in both contexts. Perceptions of vulnerability, together with the presence or absence of socio-economic barriers or enablers influenced at what time patients would seek help. The study suggests that health personnel lacked awareness or misinterpreted early symptoms of TB. In Ethiopia, lay categorizations of early TB symptoms converged with diagnostic practices in parts of the professional health sector. The diagnostic process could endure for many months after patients’ first contact with the health services. Similarly, in Norway, we found that patients’ interpretations of early symptoms often were confirmed in the meeting with health personnel. The consequences were prolonged diagnostic processes. The study shows that patients’ ability to manage TB treatment is a product of dynamic processes, in which social and economic costs and other burdens interplay over time. A decision to interrupt treatment can be shaped by past struggles and accrued costs; in which seems financially, socially or emotionally unbearable at the moment of treatment interruption. The burdens related to DOT could also be significant, in patients who did not interrupt treatment. Patients in both Ethiopia and Norway experienced an authoritarian and rigid practice of DOT, which made it difficult to simultaneously attend to demands related to treatment and demands related to other areas of life. The most vulnerable patients, such as those without permanent jobs, suffered from high economic, social and emotional costs. In conclusion, health personal need more knowledge about typical and atypical symptoms of TB. In low-endemic settings doctors need to be trained to adjust their level of suspicion to the migration history of the patient. In high-endemic settings one should be aware that health personnel may understand and manage TB within a traditional perspective. Patients in both high- and low-endemic contexts need concrete information about the cause of TB, how it is transmitted, how symptoms can be manifested, how the disease can progress and how it can be cured. The study indicates that inequalities that predispose for TB may be reinforced in the patient’s interaction with the health services due to a rigid, disempowering practice of DOT. Subsequently, DOT per se may add to the chain of structural barriers that patients have to overcome to access and complete treatment. To ensure that TB patients complete treatment one must address the coexisting and interacting crises that follow a TB diagnosis. This could require TB programs to adopt a more holistic approach. Measures that secure early diagnosis may reduce some of the physical, psycho-social and economic costs patients face while undergoing treatment. Measures that empower patients to participate in their own health care may avoid disempowering and humiliating practices

    Lymph vascular invasion in invasive mammary carcinomas identified by the endothelial lymphatic marker D2-40 is associated with other indicators of poor prognosis

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    <p>Abstract</p> <p>Background</p> <p>Immunohistochemical studies of lymphatic vessels have been limited by a lack of specific markers. Recently, the novel D2-40 antibody, which selectively marks endothelium of lymphatic vessels, was released. The aim of our study is to compare lymphatic and blood vessel invasion detected by hematoxylin and eosin (H&E) versus that detected by immunohistochemistry, relating them with morphologic and molecular prognostic factors.</p> <p>Methods</p> <p>We selected 123 cases of invasive mammary carcinomas stratified into three subgroups according to axillary lymph node status: macrometastases, micrometastases, and lymph node negative. Lymphatic (LVI) and blood (BVI) vessel invasion were evaluated by H&E and immunohistochemistry using the D2-40 and CD31 antibodies, and related to histologic tumor type and grade, estrogen and progesterone receptors, E-cadherin, Ki67, p53, and Her2/<it>neu </it>expression.</p> <p>Results</p> <p>LVI was detected in H&E-stained sections in 17/123 cases (13.8%), and in D2-40 sections in 35/123 cases (28.5%) (Kappa = 0.433). BVI was detected in H&E-stained sections in 5/123 cases (4.1%), and in CD31 stained sections in 19/123 cases (15.4%) (Kappa = 0.198). LVI is positively related to higher histologic grade (p = 0.013), higher Ki67 expression (p = 0.00013), and to the presence of macrometastases (p = 0.002), and inversely related to estrogen (p = 0.0016) and progesterone (p = 0.00017) receptors expression.</p> <p>Conclusion</p> <p>D2-40 is a reliable marker of lymphatic vessels and is a useful tool for lymphatic emboli identification in immunostained sections of breast carcinomas with higher identification rates than H&E. Lymphatic vessel invasion was related to other features (high combined histologic grade, high Ki67 score, negative hormone receptors expression) associated with worse prognosis, probable reflecting a potential for lymphatic metastatic spread and aggressive behavior.</p
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