ThresholdROC: Optimum Threshold Estimation Tools for Continuous Diagnostic Tests in R

We introduce an R package that estimates decision thresholds in diagnostic settings with a continuous marker and two or three underlying states. The package implements parametric and non-parametric estimation methods based on minimizing an overall cost function, as well as confidence interval estimation approaches to account for the sampling variability of the cut-off. Further features of the package include sample size determination and estimation of diagnostic accuracy measures. We used randomly generated data and two real datasets to illustrate the capabilities and characteristics of the package

Evaluation of the PaO2/FiO2 ratio after cardiac surgery as a predictor of outcome during hospital stay

Background: the arterial partial pressure of O2 and the fraction of inspired oxygen (PaO2/FiO2) ratio is widely used in ICUs as an indicator of oxygenation status. Although cardiac surgery and ICU scores can predict mortality, during the first hours after cardiac surgery few instruments are available to assess outcome. The aim of this study was to evaluate the usefulness of PaO2/FIO2 ratio to predict mortality in patients immediately after cardiac surgery. Methods: we prospectively studied 2725 consecutive cardiac surgery patients between 2004 and 2009. PaO2/FiO2 ratio was measured on admission and at 3 h, 6 h, 12 h and 24 h after ICU admission, together with clinical data and outcomes. Results: all PaO2/FIO2 ratio measurements differed between survivors and non-survivors (p  242; Group 2, with PaO2/FIO2 from 202 to 242; and Group 3, with PaO2/FIO2 < 202. Group 3 showed higher in-ICU mortality and ICU length of stay and Groups 2 and 3 also showed higher respiratory complication rates. The presence of a PaO2/FIO2 ratio < 202 at 3 h after admission was shown to be a predictor of in-ICU mortality (OR:1.364; 95% CI:1.212-1.625, p < 0.001) and of worse long-term survival (88.8% vs. 95.8%; Log rank p = 0.002. Adjusted Hazard ratio: 1.48; 95% CI:1.293-1.786; p = 0.004). Conclusions: a simple determination of PaO2/FIO2 at 3 h after ICU admission may be useful to identify patients at risk immediately after cardiac surgery

The association between health-related quality-of-life scores and clinical outcomes in metastatic castration-resistant prostate cancer patients: Exploratory analyses of AFFIRM and PREVAIL studies.

BACKGROUND: Our exploratory analysis examined the association between health-related quality of life (HRQoL) (baseline and change over time) and clinical outcomes (overall survival [OS]/radiographic progression-free survival [rPFS]) in metastatic castration-resistant prostate cancer (mCRPC). METHODS: HRQoL, OS and rPFS were assessed in phase III trials comparing enzalutamide with placebo in chemotherapy-naïve (PREVAIL; NCT01212991) or post-chemotherapy (AFFIRM; NCT00974311) mCRPC. HRQoL was assessed using the Functional Assessment of Cancer Therapy-Prostate (FACT-P). Multivariate analyses evaluated the prognostic significance of baseline and time-dependent scores after adjusting for treatment and clinical/demographic variables. Hazard ratios (HRs) and 95% confidence intervals (CIs) represented the hazard of rPFS or OS per minimally important difference (MID) score change in HRQoL variables. RESULTS: In baseline and time-dependent multivariate analyses, OS was independently associated with multiple HRQoL measures across both studies. In time-dependent analyses, a 10-point (upper bound of MID range) increase (improvement) in FACT-P total score was associated with reductions in mortality risk of 19% in AFFIRM (HR 0.81 [95% CI 0.78-0.84]) and 21% in PREVAIL (HR 0.79 [0.76-0.83]). For baseline analyses, a 10-point increase in FACT-P total score was associated with reductions in mortality risk of 12% (HR 0.88 [0.84-0.93]) and 10% (HR 0.90 [0.86-0.95]) in AFFIRM and PREVAIL, respectively. rPFS was associated with a subset of HRQoL domains in both studies. CONCLUSION: Several baseline HRQoL domains were prognostic for rPFS and OS in patients with mCRPC, and this association was maintained during treatment, indicating that changes in HRQoL are informative for patients' expected survival

Chemical Profile and In Vitro Evaluation of the Antibacterial Activity of Dioscorea communis Berry Juice

Within the large family of Dioscoreaceae, Dioscorea communis (L.) Caddick &amp; Wilkin (syn. Tamus communis L.) is considered among the four most widespread representatives in Europe, and it is commonly known under the name black bryony or bryonia. To date, reports have revealed several chemical components from the leaves and tubers of this plant. Nevertheless, an extensive phytochemical investigation has not been performed on its berry juice. In the present study, metabolite profiling procedures, using LC-MS, GC-MS, and NMR approaches, were applied to investigate the chemical profile of the D. communis berries. This work reveals the presence of several metabolites belonging to different phytochemical groups, such as fatty acid esters, alkylamides, phenolic derivatives, and organic acids, with lactic acid being predominant. In parallel, based on orally transmitted traditional uses, the initial extract and selected fractions were tested in vitro for their antibacterial effects and exhibited good activity against two bacterial strains related to skin infections: methicillin-resistant Staphylococcus aureus and Cutibacterium acnes. The MIC and MBC values of the extract were determined at 1.56% w/v against both bacteria. The results of this study provide important information on the chemical characterization of the D. communis berry juice, unveiling the presence of 71 metabolites, which might contribute to and further explain its specific antibacterial activity and its occasional toxicity