Centralising acute stroke care within clinical practice in the Netherlands: lower bounds of the causal impact

BACKGROUND Authors in previous studies demonstrated that centralising acute stroke care is associated with an increased chance of timely Intra-Venous Thrombolysis (IVT) and lower costs compared to care at community hospitals. In this study we estimated the lower bound of the causal impact of centralising IVT on health and cost outcomes within clinical practice in the Northern Netherlands. METHODS We used observational data from 267 and 780 patients in a centralised and decentralised system, respectively. The original dataset was linked to the hospital information systems. Literature on healthcare costs and Quality of Life (QoL) values up to 3 months post-stroke was searched to complete the input. We used Synthetic Control Methods (SCM) to counter selection bias. Differences in SCM outcomes included 95% Confidence Intervals (CI). To deal with unobserved heterogeneity we focused on recently developed methods to obtain the lower bounds of the causal impact. RESULTS Using SCM to assess centralising acute stroke 3 months post-stroke revealed healthcare savings of $US 1735 (CI, 505 to 2966) while gaining 0.03 (CI, − 0.01 to 0.73) QoL per patient. The corresponding lower bounds of the causal impact are$US 1581 and 0.01. The dominant effect remained stable in the deterministic sensitivity analyses with $US 1360 (CI, 476 to 2244) as the most conservative estimate. CONCLUSIONS In this study we showed that a centralised system for acute stroke care appeared both cost-saving and yielded better health outcomes. The results are highly relevant for policy makers, as this is the first study to address the issues of selection and unobserved heterogeneity in the evaluation of centralising acute stroke care, hence presenting causal estimates for budget decisions

A patient with an acute neurological deficit:is it really an ischemic stroke?

A patient with an acute neurological deficit: is it really an ischemic stroke?When a patient presents with acute neurological deficit, ischemic stroke is often assumed. However, a functional neurological disorder (FND) can also present with stroke-like symptoms. FND is a multifactorial condition to which biological, psychological and social factors predispose. The distinction between FND and acute ischemic stroke can be challenging, but is very important because fast reperfusion treatment is indicated for ischemic stroke. We show the specific features of FND in history and neurologic examination to pay attention to. Furthermore, we discuss the use of additional investigation to support the diagnosis. We describe two patients with an acute neurological deficit: a 34-year-old male with hemiparesis and speech disturbances due to FND, and a 51-year-old male with hemiparesis and hemi-ataxia due to ischemic stroke. These 2 patients demonstrate how challenging the distinction between FND and stroke may be.Conflict of interest and financial support: potential conflicts of interest have been reported for this article. ICMJE forms provided by the authors are available online along with the full text of this article.When a patient presents with acute neurological deficit, ischemic stroke is often assumed. However, a functional neurological disorder (FND) can also present with stroke-like symptoms. FND is a multifactorial condition to which biological, psychological and social factors predispose. The distinction between FND and acute ischemic stroke can be challenging, but is very important because fast reperfusion treatment is indicated for ischemic stroke. We show the specific features of FND in history and neurologic examination to pay attention to. Furthermore, we discuss the use of additional investigation to support the diagnosis. We describe two patients with an acute neurological deficit: a 34-year-old male with hemiparesis and speech disturbances due to FND, and a 51-year-old male with hemiparesis and hemi-ataxia due to ischemic stroke. These 2 patients demonstrate how challenging the distinction between FND and stroke may be.</p

Spin-Momentum Correlations in Quasi-Elastic Electron Scattering from Deuterium

We report on a measurement of spin-momentum correlations in quasi-elastic scattering of longitudinally polarized electrons with an energy of 720 MeV from vector-polarized deuterium. The spin correlation parameter $A^V_{ed}$ was measured for the $^2 \vec{\rm H}(\vec e,e^\prime p)n$ reaction for missing momenta up to 350 MeV/$c$ at a four-momentum transfer squared of 0.21 (GeV/c)$^2$. The data give detailed information about the spin structure of the deuteron, and are in good agreement with the predictions of microscopic calculations based on realistic nucleon-nucleon potentials and including various spin-dependent reaction mechanism effects. The experiment demonstrates in a most direct manner the effects of the D-state in the deuteron ground-state wave function and shows the importance of isobar configurations for this reaction.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Lett. for publicatio

The predictive value of the CTA Vasospasm Score on delayed cerebral ischaemia and functional outcome after aneurysmal subarachnoid hemorrhage

Background and purpose: Delayed cerebral ischaemia (DCI) is a severe complication of aneurysmal subarachnoid hemorrhage that can significantly impact clinical outcome. Cerebral vasospasm is part of the pathophysiology of DCI and therefore a computed tomography angiography (CTA) Vasospasm Score was developed and an exploration was carried out of whether this score predicts DCI and subsequent poor outcome after aneurysmal subarachnoid hemorrhage. Methods: The CTA Vasospasm Score sums the degree of angiographic cerebral vasospasm of 17 intradural arterial segments. The score ranges from 0 to 34 with a higher score reflecting more severe vasospasm. Outcome measures were cerebral infarction due to DCI (CI-DCI), radiological and clinical DCI, and unfavorable functional outcome defined as a modified Rankin Scale >2 at 6 months. Receiver operating characteristic analyses were used to assess predictive value and to determine optimal cut-off scores. Inter-rater reliability was evaluated by Cohen's kappa coefficient. Results: This study included 59 patients. CI-DCI occurred in eight patients (14%), DCI in 14 patients (24%) and unfavorable outcome in 12 patients (20%). Median CTA Vasospasm Scores were higher in patients with (CI-)DCI and poor outcome. Receiver operating characteristic analysis revealed the highest area under the curve on day 5: CI-DCI 0.89 (95% confidence interval [CI] 0.79–0.99), DCI 0.68 (95% CI 0.50–0.87) and functional outcome 0.74 (95% CI 0.57–0.91). Cohen's kappa between the two raters was moderate to substantial (0.57–0.63). Conclusions: This study demonstrates that the CTA Vasospasm Score on day 5 can reliably identify patients with a high risk of developing (CI-)DCI and unfavorable outcome

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011