Search results for "Random"

2013

Background: Nonpharmacological secondary prevention of coronary heart disease is considered a safe and effective measure to substantially reduce mortality. Despite the effectiveness of lifestyle changes, the compliance rate of patients is very low mainly due to psychosocial barriers. Psychotherapeutic approaches that address how persons think about themselves and their behaviors appear to have a significant potential for improving health behavior. Methods/design: Against this background, our study aims to examine the feasibility and effects of a Psychodynamic Motivation and Training program (PMT) as compared to one session of advice in exercise training (EX) and treatment as usual (TAU). Fo…

The Effects of Using High-Fidelity Simulation in Undergraduate Nursing Education: A Multicenter Randomized Controlled Trial with a Process Evaluation

2021

Abstract The overall aim of this study was to examine the effects of a high-fidelity simulation on the knowledge and self-confidence of a total of 177 undergraduate nursing students in recognizing and responding to hypovolemia. A randomized experimental pre- and post-test research design with a process evaluation was employed. A significantly larger proportion of students in the intervention group than in the control group increased the number of correct responses in their knowledge and levels of self-confidence postintervention. As enablers for the successful implementation of the intervention, a need for a safe environment, fidelity, and learning in different roles were identified.

SEQUENTIALLY ADJUSTED RANDOMIZATION TO FORCE BALANCE IN CONTROLLED TRIALS WITH UNKNOWN PREVALENCE OF COVARIATES: APPLICATION TO ALCOHOLISM RESEARCH

2005

In treatment outcome studies with small to medium sample sizes (n200), the balance of groups with regard to important factors, which sometimes occur at low prevalence, is indispensable for adequate interpretation. This study tested a method for use in clinical alcoholism research, an uncomplicated procedure for satisfactory randomization of patients to different treatments, taking into account relevant background variables.An easily applicable modification of Efron's biased coin method for the randomization of treatments within strata of unknown but low prevalence was compared with the original approach and alternative methods by computer simulation (10,000 runs). An application example for…

Covariate-constrained Randomization Routine for Achieving Baseline Balance in Cluster-randomized Trials

2017

In cluster-randomized trials, groups or clusters of individuals, rather than individuals themselves, are randomly allocated to intervention or control. In this article, we describe a new command, ccrand, that implements a covariate-constrained randomization procedure for cluster-randomized trials. It can ensure balance of one or more baseline covariates between trial arms by restriction to allocations that meet specified balance criteria. We provide a brief overview of the theoretical background, describe ccrand and its options, and illustrate it using an example.

Contributions to the study of returns to education : the Tunisian case

2016

In Tunisia, enrollment rates in tertiary education had soared up over the past two decades. A significant increase of student annual flows imposed the implementation of reforms that led to an increase in the number of higher education institutions and universities. One of the challenges in Tunisia and many African countries is to improve the efficiency of education systems to promote employability and graduates employment. This thesis discuss the question of the efficiency of education from an economic approach based on returns to education in the labor market. The first chapter analyses private returns to education particularly higher education in African countries. Our findings highlight …

Random Lasing of Rhodamine 6G Solution Containing TiO2:Silica Core:Shell Nanoparticles

2012

High efficiency and low rate of photodegradation was obtained in a random laser suspending TiO2@Silica nanoparticles in ethanol solution of Rhodamine 6G. The TiO2 nanoparticles were coated with a silica shell prepared via Stober method.

Representation of solutions and large-time behavior for fully nonlocal diffusion equations

2017

Abstract We study the Cauchy problem for a nonlocal heat equation, which is of fractional order both in space and time. We prove four main theorems: (i) a representation formula for classical solutions, (ii) a quantitative decay rate at which the solution tends to the fundamental solution, (iii) optimal L 2 -decay of mild solutions in all dimensions, (iv) L 2 -decay of weak solutions via energy methods. The first result relies on a delicate analysis of the definition of classical solutions. After proving the representation formula we carefully analyze the integral representation to obtain the quantitative decay rates of (ii). Next we use Fourier analysis techniques to obtain the optimal dec…

Exercise training improves peak oxygen consumption and hemodynamics in patients with pulmonary hypertension – A prospective, randomized, controlled t…

2016

Aims: This prospective randomized controlled study investigates the effects of exercise training on peak VO 2 /kg, hemodynamics and further clinically relevant parameters in pulmonary hypertension (PH) patients. Methods: Eighty-seven patients with pulmonary arterial hypertension and inoperable chronic thromboembolic PH (54% female, 56±15years, 84% WHO functional class III/IV, 53% combination therapy) on stable disease-targeted medication were randomly assigned to a control and training group. Medication remained unchanged during the study period. Non-invasive assessments and right heart catheterization at rest and during exercise were performed at baseline and after 15 weeks. Primary endpoi…

Liver failure after partial hepatic resection: definition, pathophysiology, risk factors and treatment

2008

Liver failure is a dreaded and often fatal complication that sometimes follows a partial hepatic resection. This article reviews the definition, incidence, pathogenesis, risk factors, risk assessment, prevention, clinical features and treatment of post-resectional liver failure (PLF). A systematic, computerized search was performed using key words related to 'partial hepatic resection' and 'liver failure' to review most relevant literature about PLF published in the last 20 years. The reported incidence of PLF ranges between 0.7 and 9.1%. An inadequate quantity or quality of residual liver mass are key events in its pathogenesis. Major risk factors are the presence of comorbid conditions, p…

The impact of deep vein thrombosis in critically ill patients: a meta-analysis of major clinical outcomes

2015

Background. Critically ill patients appear to be at high risk of developing deep vein thrombosis (DVT) and pulmonary embolism during their stay in the intensive care unit (ICU). However, little is known about the clinical course of venous thromboembolism in the ICU setting. We therefore evaluated, through a systematic review of the literature, the available data on the impact of a diagnosis of DVT on hospital and ICU stay, duration of mechanical ventilation and mortality in critically ill patients. We also tried to determine whether currently adopted prophylactic measures need to be revised and improved in the ICU setting. Materials and methods. MEDLINE and EMBASE databases were searched up…