Problems in RMSE-based wave model validations

In order to evaluate the reliability of numerical simulations in geophysical applications it is necessary to pay attention when using the root mean square error (RMSE) and two other indicators derived from it (the normalized root mean square error (NRMSE), and the scatter index (SI)). In the present work, in fact, we show on a general basis that, in conditions of constant correlation coefficient, the RMSE index and its variants tend to be systematically smaller (hence identifying better performances of numerical models) for simulations affected by negative bias. Through a geometrical decomposition of RMSE in its components related to the average error and the scatter error it can be shown that the above mentioned behavior is triggered by a quasi-linear dependency between these components in the neighborhood of null bias. This result suggests that smaller values of RMSE, NRMSE and SI do not always identify the best performances of numerical simulations, and that these indicators are not always reliable to assess the accuracy of numerical models. In the present contribution we employ the corrected indicator proposed by Hanna and Heinold (1985) to develop a reliability analysis of wave generation and propagation in the Mediterranean Sea by means of the numerical model WAVEWATCH III®, showing that the best values of the indicator are obtained for simulations unaffected by bias. Evidences suggest that this indicator provides a more reliable information about the accuracy of the results of numerical models. © 2013 Elsevier Ltd

Guillain-Barré Syndrome with Fatal Outcome during HIV-1-Seroconversion: A Case Report

Guillain-Barré syndrome (GBS) is an acute or subacute peripheral polyneuropathy characterized by symmetrical muscle weakness. Its occurrence has been reported during acute HIV seroconversion since 1985. Among HIV-infected subjects, GBS has generally a favourable outcome. We report a case of GBS with fatal outcome during HIV seroconversion

REAL-TIME ELASTOGRAPHY IN THE ASSESSMENT OF LIVER FIBROSIS: A REVIEW OF QUALITATIVE AND SEMI-QUANTITATIVE METHODS FOR ELASTOGRAM ANALYSIS

Despite its invasiveness, liver biopsy is still considered the gold standard for the assessment of hepatic fibrosis. Non-invasive ultrasound-based techniques are increasingly employed to assess parenchymal stiffness and the progression of chronic diffuse liver diseases. Real-time elastography is a rapidly evolving technique that can reveal the elastic properties of tissues. This review examines qualitative and semi-quantitative methods developed for analysis of real-time liver elastograms, to estimate parenchymal stiffness and, indirectly, the stage of fibrosis. Qualitative analysis is the most immediate approach for elastogram analysis, but this method increases intra- and inter-observervariability,whichisseenasamajorlimitationofreal-timeelastography.Semi-quantitativemethods include analysis of the histogram derived from color-coded maps, as well as calculation of the elastic ratio and fibrosis index. (E-mail: [email protected]) 2014 World Federation for Ultrasound in Medicine & Biology

Budget impact analysis of sofosbuvir-based regimens for the treatment of HIV/HCV-coinfected patients in northern Italy: A multicenter regional simulation

Objectives: Chronic hepatitis C virus (HCV) is a leading cause of hospitalization and death in populations coinfected with human immunodeficiency virus (HIV). Sofosbuvir (SOF) is a pan-genotypic drug that should be combined with other agents as an oral treatment for HCV. We performed a 5-year horizon budget impact analysis of SOF-based regimens for the management of HIV/HCV-coinfected patients. Methods: A multicenter, prospective evaluation was conducted, involving four Italian Infectious Diseases Departments (Galliera, San Martino, Sanremo, and La Spezia). All 1,005 genotype-coinfected patients (30% cirrhotics) under observation were considered (patients in all disease-stages were considered: chronic hepatitis C, cirrhosis, transplant, hepatocellular carcinoma). Disease stage costs per patient were collected; the expected disease progression in the absence of treatment and sustained virological response (SVR) success rate for SOF-based regimens were calculated based on the literature and expert opinion. Drug prices were based on what the National Health Service paid for them. The comparison of \u201cno treatment\u201d disease progression costs versus the economic impact of SOF-based regimens was investigated. Results: Over the following 5 years, the disease progression scenario resulted in direct costs of approximately \u20ac54 million. Assuming an SVR success rate of 90%, average SOF-based regimens cost up to \u20ac50,000 per person, resulting in a final cost of more than \u20ac56 million, so this option is not economically viable. At the average price of \u20ac12,000, SOF-based regimens, expense was \u20ac17 million, saving 68%. At this price level, the economic resources invested in treating mild to moderate fibrosis stage patients would be equal to the amount of direct costs of disease management in this stage, resulting in a valid return of investment in the short-term. Conclusion: Given the high rates of SVR, in the Italian Healthcare System, SOF-based regimens, price is a determinant and a predictor of the overall cost for the Hepatitis C patient\u2019s management. At the average price per therapy of \u20ac12,000 over the next 5 years, SOF-based regimens are becoming highly sustainable

Is it still worthwhile to perform quarterly CD4+ T lymphocyte cell counts on HIV-1 infected stable patients?

Background: In the last twenty years routine T CD4+ lymphocyte (CD4) cell count has proved to be a key factor to determine the stage of HIV infection and start or discontinue of prophylaxis for opportunistic infections. However, several studies recently showed that in stable patients on cART a quarterly CD4 cell count monitoring results in limited (or null) clinical relevance. The research is intended to investigate whether performing quarterly CD4 cell counts in stable HIV-1 patients is still recommendable and to provide a forecast of the cost saving that could be achieved by reducing CD4 monitoring in such a category of patients. Methods: The study is based on data referring to all HIV-infected patients > 18 years of age being treated at two infectious diseases units located in the metropolitan area of Genoa, Italy. The probability of CD4 cell counts dropping below a threshold value set at 350 cells/mm3 is assessed using confidence intervals and Kaplan-Meier survival estimates, whereas multivariate Cox analysis and logistic regression are implemented in order to identify factors associated with CD4 cell count falls below 350 cells/mm3. Results: Statistical analysis reveals that among stable patients the probability of maintaining CD4 >350 cell/mm3 is more than 98%. Econometric models indicate that HCV co-infection and HIV-RNA values >50 copies/mL in previous examinations are associated with CD4 falls below 350 cells/mm3. Moreover, results suggest that the cost saving that could be obtained by reducing CD4 examinations ranges from 33% to 67%. Conclusions: Empirical findings show that patients defined as stable at enrollment are highly unlikely to experience a CD4 value <350 cell/mm3 in the space/arc of a year. The research supports a recommendation for annual CD4 monitoring in stable HIV-1 patients

Time to change the single-centre approach to management of patients with tuberculosis: a novel network platform with automatic data import and data sharing

Time to change the single-centre approach to TB http://ow.ly/lCeM30hBcbB

Epidemiology, management, and outcome of carbapenem-resistant Klebsiella pneumoniae bloodstream infections in hospitals within the same endemic metropolitan area

In the last decade, carbapenem-resistant Klebsiella pneumoniae (CR-Kp) has become endemic in several countries, including Italy. In the present study, we assessed the differences in epidemiology, management, and mortality of CR-Kp bloodstream infection (BSI) in the three main adult acute-care hospitals of the metropolitan area of Genoa, Italy.From January 2013 to December 2014, all patients with CR-Kp BSI were identified through the computerized microbiology laboratory databases of the three hospitals. The primary endpoints of the study were incidence and characteristics of CR-Kp BSI in hospitals within the same endemic metropolitan area. Secondary endpoints were characteristics of CR-Kp BSI in hospitals with and without internal infectious diseases consultants (IDCs) and 15-day mortality.During the study period, the incidence of healthcare-associated CR-Kp BSI in the entire study population was 1.35 episodes per 10,000 patient-days, with substantial differences between the three hospitals. Patients admitted to the two hospital with internal IDCs were more likely to receive post-susceptibility test combined therapy including carbapenems (77% vs. 26%, p <. 0.001), adequate post-susceptibility test therapies (86% vs. 52%, p <. 0.001), and post-susceptibility therapies prescribed by an infectious diseases specialist (84% vs. 14%, p <. 0.001). Overall, the crude 15-days mortality was 26%. In the final multivariable model, only septic shock at BSI presentation was unfavorably and independently associated with 15-days mortality (odds ratio [OR] 6.7, 95% confidence intervals [CI] 2.6-17.6, p <. 0.001), while a protective effect was observed for post-susceptibility test combined therapies including a carbapenem (OR 0.11, 95% CI 0.03-0.43, p = 0.002).Mortality of CR-Kp remains high. Differences in the incidence of CR-Kp BSI were detected between acute-care centers within the same endemic metropolitan area. Efforts should be made to improve the collaboration and coordination between centers, to prevent further diffusion of CR-Kp

The importance of active surveillance in the intensive care unit of Galliera Hospital in Genoa. Analysis of bacterial strains isolated in 2006-2007

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