In this work, we use Martingale theory to derive formulas for the expected decision time, error rates, and first passage times associated with a multistage drift diffusion model, or a Wiener ...diffusion model with piecewise constant time-varying drift rates and decision boundaries. The model we study is a generalization of that considered in Ratcliff (1980). The derivation relies on using the optional stopping theorem for properly chosen Martingales, thus obtaining formulae which may be used to compute performance metrics for a particular stage of the stochastic decision process. We also explicitly solve the case of a two stage diffusion model, and provide numerical demonstrations of the computations suggested by our analysis. Finally we present calculations that allow our techniques to approximate time-varying Ornstein-Uhlenbeck processes. By presenting these explicit formulae, we aim to foster the development of refined numerical methods and analytical techniques for studying diffusion decision processes with time-varying drift rates and thresholds.
We hereby present two case reports of moderate coronavirus disease patients, suffering from profound hypoxaemia, further deteriorating later on. A schedule pre-planned awake prone position manoeuvres ...were executed during their hospital stay. Following this, the patients' saturation improved, later to be weaned from oxygen support. Paucity of evidence and data regarding this topic led us to review the concept of awake prone position.
In February 2020, the World Health Organisation designated the name COVID-19 for a clinical condition caused by a virus identified as a cause for a cluster of pneumonia cases in Wuhan, China. The ...virus subsequently spread worldwide, causing havoc to medical systems and paralyzing global economies. The first COVID-19 patient in Israel was diagnosed on 27 February 2020.
To present our findings and experiences as the first and largest center for COVID-19 patients in Israel.
The current analysis included all COVID-19 patients treated in Sheba Medical Center from February 2020 to April 2020. Clinical, laboratory, and epidemiological data gathered during their hospitalization are presented.
Our 162 patient cohort included mostly adult (mean age of 52 ± 20 years) males (65%). Patients classified as severe COVID-19 were significantly older and had higher prevalence of arterial hypertension and diabetes. They also had significantly higher white blood cell counts, absolute neutrophil counts, and lactate dehydrogenase. Low folic acid blood levels were more common amongst severe patients (18.2 vs. 12.9 vs. 9.8, P = 0.014). The rate of immune compromised patients (12%) in our cohort was also higher than in the general population. The rate of deterioration from moderate to severe disease was high: 9% necessitated non-invasive oxygenation and 15% were intubated and mechanically ventilated. The mortality rate was 3.1.
COVID-19 patients present a challenge for healthcare professionals and the whole medical system. We hope our findings will assist other providers and institutions in their care for these patients.
Sarcopenia and frailty are causes for morbidity and mortality amongst heart failure (HF) patients. Low alanine transaminase (ALT) is a marker for these syndromes and, therefore, could serve as a ...biomarker for the prognostication of HF patients. We performed a retrospective analysis of all consecutive hospitalized HF patients in our institute in order to find out whether low ALT values would be a biomarker for poor outcomes. Our cohort included 11,102 patients, 35.6% categorized as heart failure with reduced ejection fraction. We excluded patients with ALT > 40 IU/L and cirrhosis. 8700 patients were followed for a median duration of 22 months and included in a univariate analysis. Patients with ALT < 10 IU/L were older (mean age 78.6 vs. 81.8, p < 0.001), had past stroke (24.6% vs. 19.6%, p < 0.001), dementia (7.7% vs. 4.6%, p < 0.001), and malignancy (13.4% vs. 10.2%, p = 0.003). Hospitalization length was longer in the low-ALT group (4 vs. 3 days, p < 0.001), and the rate of acute kidney injury during hospitalization was higher (19.1% vs. 15.6%; p = 0.006). The in-hospital mortality rate was higher in the low-ALT group (6.5% vs. 3.9%; p < 0.001). Long-term mortality was also higher (73.3% vs. 61.5%; p < 0.001). In a multivariate regression analysis, ALT < 10 IU/L had a 1.22 hazard ratio for mortality throughout the follow-up period (CI = 1.09–1.36; p < 0.001). Low ALT plasma level, a biomarker for sarcopenia and frailty, can assist clinicians in prognostic stratification of heart failure patients.
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