The aim of this study was to examine the effect of weight loss on health-related quality of life (HRQL) in randomized controlled intervention trials (RCTs). MEDLINE, HealthStar and PsycINFO were searched. RCTs of any weight loss intervention and 20 HRQL instruments were examined. Contingency tables were constructed to examine the association between statistically significant weight loss and statistically significant HRQL improvement within five HRQL categories. In addition, Short Form-36 (SF-36) outcomes were pooled using random-effects models. Fifty-three trials were included. Seventeen studies reported statistically significant weight loss and HRQL improvement. No statistically significant associations between weight loss and HRQL improvement were found in any contingency table. Because of suboptimal endpoint reporting, quantitative data pooling could only be performed using 25% of SF-36 trials in any one model. Significant improvements in physical health were found: mean difference 2.83 points, 95% CI 0.55-5.1, for the physical component score, and mean difference 6.81 points, 95% CI 2.99-10.63, for the physical functioning domain score. Conversely, no significant improvements in mental health were found. No significant association was found between weight loss and overall HRQL improvement. Weight loss may be associated with modest improvements in physical, but not mental, health.

In the context of unitary evolution of a generic quantum system interrupted at random times with non-unitary evolution due to interactions with either the external environment or a measuring apparatus, we adduce a general theoretical framework to obtain the average density operator of the system at any time during the dynamical evolution. The average is with respect to the classical randomness associated with the random time intervals between successive interactions, which we consider to be independent and identically-distributed random variables. The formalism is very general in that it applies to any quantum system, to any form of non-unitary interaction, and to any probability distribution for the random times. We provide two explicit applications of the formalism in the context of the so-called tight-binding model relevant in various contexts in solid-state physics, e.g. in modelling nano wires. Considering the case of one dimension, the corresponding tight-binding chain models the motion of a charged particle between the sites of a lattice, wherein the particle is for most times localized on the sites, owing to spontaneous quantum fluctuations tunnels between the nearest-neighbour sites. We consider two representative forms of interactions, one that implements a stochastic reset of quantum dynamics in which the density operator is at random times reset to its initial form, and one in which projective measurements are performed on the system at random times. In the former case, we demonstrate with our exact results how the particle is localized on the sites at long times, leading to a time-independent mean-squared displacement (MSD) of the particle about its initial location. This stands in stark contrast to the behavior in the absence of interactions, when the particle has an unbounded growth of the MSD in time, with no signatures of localization. In the case of projective measurements at random times, we show that repeated projection to the initial state of the particle results in an effective suppression of the temporal decay in the probability of the particle to be found on the initial state. The amount of suppression is comparable to the one in conventional Zeno effect scenarios, but which it does not require us to perform measurements at exactly regular intervals that are hallmarks of such scenarios.

IMPORTANCE Pragmatic trials test interventions using designs that produce results that may be more applicable to the population in which the intervention will be eventually applied. OBJECTIVE To investigate how pragmatic or explanatory cardiovascular (CV) randomized clinical trials (RCT) are, and if this has changed over time.

T he clinical outcome of patients with STsegment elevation myocardial infarction (STEMI) is directly related to the extent of myocardial necrosis.1 Because the extent of necrosis is strongly influenced by the duration of symptoms, time is a key clinical proxy for the stage of evolution of STEMI.2 The length of time from the onset of symptoms is important in strategies for triage and management and for gauging prognosis. Although time from the occurrence of epicardial artery occlusion in a laboratory experimental model can be measured precisely, time from the onset of symptoms is often difficult to accurately estimate because of subjectivity and reliance on recall. Thus, establishing a more reliable method for determining the stage of myocardial infarction (MI) evolution in patients with STEMI would be useful for evaluating the potential for myocardial salvage and guiding clinical management.There is evidence that the assessment of Q waves on the baseline electrocardiogram (ECG) in the region of ST-segment elevation may be a useful predictor of left ventricular dysfunction and outcomes in patients with STEMI given streptokinase within four to six hours of the onset of symptoms. 3,4 Because prior studies of the predictive value of baseline Q waves focused on patients receiving fibrinolytic therapy, we extended this question to a large population of patients with STEMI who were at high risk of adverse clinical outcomes (e.g., death,