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The Passive Surveillance Stroke Severity (PaSSV) Indicator was derived to estimate stroke severity from variables in administrative datasets but has not been externally validated.
We used linked administrative datasets to identify patients with first hospitalization for acute stroke between 2007-2018 in Alberta, Canada. We used the PaSSV indicator to estimate stroke severity. We used Cox proportional hazard models and evaluated the change in hazard ratios and model discrimination for 30-day and 1-year case fatality with and without PaSSV. Similar comparisons were made for 90-day home time thresholds using logistic regression. We also linked with a clinical registry to obtain National Institutes of Health Stroke Scale (NIHSS) and compared estimates from models without stroke severity, with PaSSV, and with NIHSS.
There were 28,672 patients with acute stroke in the full sample. In comparison to no stroke severity, addition of PaSSV to the 30-day case fatality models resulted in improvement in model discrimination (C-statistic 0.72 [95%CI 0.71–0.73] to 0.80 [0.79–0.80]). After adjustment for PaSSV, admission to a comprehensive stroke center was associated with lower 30-day case fatality (adjusted hazard ratio changed from 1.03 [0.96–1.10] to 0.72 [0.67–0.77]). In the registry sample (N = 1328), model discrimination for 30-day case fatality improved with the inclusion of stroke severity. Results were similar for 1-year case fatality and home time outcomes.
Addition of PaSSV improved model discrimination for case fatality and home time outcomes. The validity of PASSV in two Canadian provinces suggests that it is a useful tool for baseline risk adjustment in acute stroke.
During the Randomized Assessment of Rapid Endovascular Treatment (EVT) of Ischemic Stroke (ESCAPE) trial, patient-level micro-costing data were collected. We report a cost-effectiveness analysis of EVT, using ESCAPE trial data and Markov simulation, from a universal, single-payer system using a societal perspective over a patient’s lifetime.
Primary data collection alongside the ESCAPE trial provided a 3-month trial-specific, non-model, based cost per quality-adjusted life year (QALY). A Markov model utilizing ongoing lifetime costs and life expectancy from the literature was built to simulate the cost per QALY adopting a lifetime horizon. Health states were defined using the modified Rankin Scale (mRS) scores. Uncertainty was explored using scenario analysis and probabilistic sensitivity analysis.
The 3-month trial-based analysis resulted in a cost per QALY of $201,243 of EVT compared to the best standard of care. In the model-based analysis, using a societal perspective and a lifetime horizon, EVT dominated the standard of care; EVT was both more effective and less costly than the standard of care (−$91). When the time horizon was shortened to 1 year, EVT remains cost savings compared to standard of care (∼$15,376 per QALY gained with EVT). However, if the estimate of clinical effectiveness is 4% less than that demonstrated in ESCAPE, EVT is no longer cost savings compared to standard of care.
Results support the adoption of EVT as a treatment option for acute ischemic stroke, as the increase in costs associated with caring for EVT patients was recouped within the first year of stroke, and continued to provide cost savings over a patient’s lifetime.
Emergency Medical Services (EMS) systems have developed protocols for prehospital activation of the cardiac catheterization laboratory for patients with suspected ST-elevation myocardial infarction (STEMI) to decrease first-medical-contact-to-balloon time (FMC2B). The rate of “false positive” prehospital activations is high. In order to decrease this rate and expedite care for patients with true STEMI, the American Heart Association (AHA; Dallas, Texas USA) developed the Mission Lifeline PreAct STEMI algorithm, which was implemented in Los Angeles County (LAC; California USA) in 2015. The hypothesis of this study was that implementation of the PreAct algorithm would increase the positive predictive value (PPV) of prehospital activation.
This is an observational pre-/post-study of the effect of the implementation of the PreAct algorithm for patients with suspected STEMI transported to one of five STEMI Receiving Centers (SRCs) within the LAC Regional System. The primary outcome was the PPV of cardiac catheterization laboratory activation for percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG). The secondary outcome was FMC2B.
A total of 1,877 patients were analyzed for the primary outcome in the pre-intervention period and 405 patients in the post-intervention period. There was an overall decrease in cardiac catheterization laboratory activations, from 67% in the pre-intervention period to 49% in the post-intervention period (95% CI for the difference, -14% to -22%). The overall rate of cardiac catheterization declined in post-intervention period as compared the pre-intervention period, from 34% to 30% (95% CI, for the difference -7.6% to 0.4%), but actually increased for subjects who had activation (48% versus 58%; 95% CI, 4.6%-15.0%). Implementation of the PreAct algorithm was associated with an increase in the PPV of activation for PCI or CABG from 37.9% to 48.6%. The overall odds ratio (OR) associated with the intervention was 1.4 (95% CI, 1.1-1.8). The effect of the intervention was to decrease variability between medical centers. There was no associated change in average FMC2B.
The implementation of the PreAct algorithm in the LAC EMS system was associated with an overall increase in the PPV of cardiac catheterization laboratory activation.
Covert brain infarcts (CBIs) are five times more prevalent than symptomatic brain infarcts. CBIs are associated with cognitive impairment and therefore may be a target for preventing cognitive decline and dementia. This review focuses on strategies for preventing CBI-related cognitive impairment, either by preventing incident or recurrent CBI or by enhancing cognitive reserve. CBIs begin to become prevalent during midlife and are highly prevalent in later life. The distribution of vascular pathologies of CBI differs from those that cause symptomatic stroke; therefore, preventive treatments may need to differ as well. Only a few randomized clinical trials have provided data on CBI prevention, without conclusive results. Limited data suggest that higher early-life education, hypothesized to enhance cognitive reserve, can protect the brain from effects of CBI.
In 2002, a report by UNICEF and the Centers for Disease Control and Prevention (CDC) concluded that ‘Afghanistan is among the worst places on the globe in which to be pregnant’. This conclusion was reached following review of preliminary data from a large well-designed maternal mortality study conducted from 1999 to 2002 that was subsequently published in the Lancet and that reported an overall maternal mortality ratio () of 1600 maternal deaths per 100000 live births (95% CI 1100—2000). Maternal death was the leading cause of death in women of reproductive age (15—49 years) and the MMRs were among the highest in the world. In the district of Ragh in Badakhshan province, the MMR was the highest ever recorded at 6507 per 100000 live births. The study concluded that 87% of these deaths were ‘preventable’ and that maternal death was intimately linked to neonatal death (74% of babies born alive to mothers who died also died).
In 2003, my husband and I left the UK for Kabul, Afghanistan, to work with Medair (www.medair.org), a Swiss-based humanitarian relief and rehabilitation organisation. Eric took up the position of country director and I, after a short language course, moved to Ragh to begin developing Essential Obstetric Care (EOC) services in four Medair clinics as part of their Primary Health Care programme. In the ensuing months, I experienced first-hand what life was like for women in these remote villages.
Utilizing a unique data set from the Italian Ministry of Justice reporting the transmission to the Chamber of Deputies of more than the thousand requests for the removal of parliamentary immunity from deputies suspected of criminal wrongdoing, the authors analyze the political careers of members of the Chamber during the first eleven postwar legislatures (1948–94). They find that judicial investigation typically did not discourage deputies from standing for reelection in Italy's large multimember electoral districts. They also show that voters did not punish allegedly malfeasant legislators with loss of office until the last (Eleventh) legislature in the sample. To account for the dramatic change in voter behavior that occurred in the early 1990s, the investigation focuses on the roles of the judiciary and the press. The results are consistent with a theory that a vigilant and free press is a necessary condition for political accountability in democratic settings. An independent judiciary alone is ineffective in ensuring electoral accountability if the public is not informed of political malfeasance.
We show that in a sample of Extremely Metal-Poor (EMP) giants (<[Fe/H]>=−3.1) all the stars with a luminosity higher than logL/L⊙ ≈ 2.6 present the characteristics of a mixing of the surface with the H-burning layer: low abundance of carbon and high abundance of nitrogen. In these “mixed stars” the lithium abundance and the ratio 12C/13C are very low. Some of these stars are also Na or/and Al rich.
As part of a study of the detailed abundance patterns in extremely metal-poor stars, we have compared our samples of giants and dwarfs with two samples of dwarfs measured by different teams. For most elements the abundances are in good agreement, but for C, Na, and Al we show that the atmospheric abundances are different in dwarfs and in giants. For C the difference could be explained by “atmospheric effects” or by the influence of the first dredge-up, but for Na and Al deep mixing inside the stars must be invoked. Until now, such deep mixing has not been observed in metal-poor field stars. An excess scatter in [Mg/Fe] in giants remains unexplained.
To determine the ability of troponin I (TnI) measurement to predict the likelihood of a serious cardiac outcome over the subsequent 72 hours in patients presenting to the emergency department (ED) with symptoms suggestive of an acute coronary syndrome.
This prospective observational study enrolled consecutive patients presenting to 2 urban tertiary care hospital EDs over a 5-week period. Eligible patients included those for whom a TnI test was ordered within 24 hours of arrival and in whom no serious cardiac outcome occurred before the test result was available. Patients were followed for 72 hours and serious cardiac outcomes documented; these included cardiovascular death, myocardial infarction, congestive heart failure, serious arrhythmia and refractory pain. We calculated likelihood ratios (LRs) to describe the association of the TnI result with serious cardiac outcomes.
Of the 352 enrolled patients, 20 had a serious cardiac outcome within 72 hours of ED presentation. The derived LRs (and 95% confidence interval [CI]) were 0.5 (0.3–0.9) for TnI values <0.5 µg/L, 1.6 (0.4–6.5) for TnI values from 0.5 to 2.0 µg/L, 5.8 (1.7–19.5) for TnI values from >2.0 to 10.0 µg/L and 14.4 (4.8–42.9) for TnI values >10.0 µg/L.
TnI values >2.0 µg/L are associated with an increased probability of serious cardiac outcomes within 72 hours. TnI values between 0.5 and 2.0 µg/L are weakly positive predictors. TnI values <0.5 µg/L have LRs in the range of 0.5 and thus are weakly negative predictors, not substantially decreasing the likelihood of serious cardiac outcomes, particularly in patients with a moderate or high pretest probability.
Experimental measurements of material effects induced by the passage of sharp shock fronts require techniques which provide high temporal resolution and high spatial resolution. Since typical shock velocities are a few microns per nanosecond, sub-nanosecond probing requires sub-micron spatial resolution. In our experiments, the required temporal resolution is furnished using picosecond laser generated shock waves and picosecond spectroscopy. The spatial resolution is furnished by engineering nanometer scale structures into our shock target arrays. In one technique, absorption transients in the spectrum of a thin layer of molecules, termed an optical nanogauge, are investigated. Shock-induced molecular energy transfer processes are observed in condensed matter for the first time. In a second technique, sub-micron particles of an energetic material are shocked and probed using ps coherent Raman spectroscopy. This probing technique permits the instantaneous measurement of the temperature, pressure and composition of an energetic material under dynamic shock loading.