10,627 research outputs found
Influence of age on outcome from thrombolysis in acute stroke: a controlled comparison in patients from the Virtual International Stroke Trials Archive (VISTA)
<p><b>Background and Purpose:</b> Thrombolysis for acute ischemic stroke in patients aged >80 years is not approved in some countries due to limited trial data in the very elderly. We compared outcomes between thrombolysed and nonthrombolysed (control) patients from neuroprotection trials to assess any influence of age on response.</p>
<p><b>Method:</b>Among patients with ischemic stroke of known age, pretreatment severity (baseline National Institutes of Health Scale Score), and 90-day outcome (modified Rankin Scale score; National Institutes of Health Scale score), we compared the distribution of modified Rankin score in thrombolysed patients with control subjects by Cochran-Mantel-Haenszel test and then logistic regression after adjustment for age and baseline National Institutes of Health Scale score. We examined patients ≤80 and ≥ 81 years separately and then each age decile.</p>
<p><b>Results:</b> Rankin data were available for 5817 patients, 1585 thrombolysed and 4232 control subjects; 20.5% were aged >80 years (mean ± SD, 85.1 ± 3.4 years). Baseline severity was higher among thrombolysed than control subjects (median National Institutes of Health Scale score 14 versus 13, P<0.05). The distribution of modified Rankin Scale scores was better among thrombolysed patients (P<0.0001; OR, 1.39; 95% CI, 1.26 to 1.54). The association occurred independently with similar magnitude among young (P<0.0001; OR, 1.42; 95% CI, 1.26 to 1.59) and elderly (P=0.002; OR, 1.34; 95% CI, 1.05 to 1.70) patients. ORs were consistent across all age deciles >30 years; outcomes assessed by National Institutes of Health Scale score gave supporting significant findings, and dichotomized modified Rankin Scale score outcomes were also consistent.</p>
<p><b>Conclusions:</b> Outcome after thrombolysis for acute ischemic stroke was significantly better than in control subjects. Despite the expected poorer outcomes among elderly compared with young patients that is independent of any treatment effect, the association between thrombolysis treatment and improved outcome is maintained in the very elderly. Age alone should not be a barrier to treatment.</p>
Statistical analysis of the primary outcome in acute stroke trials
Common outcome scales in acute stroke trials are ordered categorical or pseudocontinuous in structure but most have been analyzed as binary measures. The use of fixed dichotomous analysis of ordered categorical outcomes after stroke (such as the modified Rankin Scale) is rarely the most statistically efficient approach and usually requires a larger sample size to demonstrate efficacy than other approaches. Preferred statistical approaches include sliding dichotomous, ordinal, or continuous analyses. Because there is no best approach that will work for all acute stroke trials, it is vital that studies are designed with a full understanding of the type of patients to be enrolled (in particular their case mix, which will be critically dependent on their age and severity), the potential mechanism by which the intervention works (ie, will it tend to move all patients somewhat, or some patients a lot, and is a common hazard present), a realistic assessment of the likely effect size, and therefore the necessary sample size, and an understanding of what the intervention will cost if implemented in clinical practice. If these approaches are followed, then the risk of missing useful treatment effects for acute stroke will diminish
Limits on τ lepton-flavor violating decays into three charged leptons
A search for the neutrinoless, lepton-flavor violating decay of the τ lepton into three charged leptons has been performed using an integrated luminosity of 468 fb^(-1) collected with the BABAR detector at the PEP-II collider. In all six decay modes considered, the numbers of events found in data are compatible with the background expectations. Upper limits on the branching fractions are set in the range (1.8–3.3)×10^(-8) at 90% confidence level
Measurement of the γγ^*→η_c transition form factor
We study the reaction e^+e^-→e^+e^-η_c, η_c→K_SK^±π^∓ and obtain η_c mass and width values 2982.2±0.4±1.6 MeV/c^2 and 31.7±1.2±0.8 MeV, respectively. We find Γ(η_c→γγ)B(ηc→KK π)=0.374±0.009±0.031 keV, and measure the γγ^*→η_c transition form factor in the momentum transfer range from 2 to 50 GeV^2. The analysis is based on 469 fb^(-1) of integrated luminosity collected at PEP-II with the BABAR detector at e^+e^- center-of-mass energies near 10.6 GeV
Prior events predict cerebrovascular and coronary outcomes in the PROGRESS trial
<p><b>Background and Purpose:</b> The relationship between baseline and recurrent vascular events may be important in the targeting of secondary prevention strategies. We examined the relationship between initial event and various types of further vascular outcomes and associated effects of blood pressure (BP)–lowering.</p>
<p><b>Methods:</b> Subsidiary analyses of the Perindopril Protection Against Recurrent Stroke Study (PROGRESS) trial, a randomized, placebo-controlled trial that established the benefits of BP–lowering in 6105 patients (mean age 64 years, 30% female) with cerebrovascular disease, randomly assigned to either active treatment (perindopril for all, plus indapamide in those with neither an indication for, nor a contraindication to, a diuretic) or placebo(s).</p>
<p><b>Results:</b> Stroke subtypes and coronary events were associated with 1.5- to 6.6-fold greater risk of recurrence of the same event (hazard ratios, 1.51 to 6.64; P=0.1 for large artery infarction, P<0.0001 for other events). However, 46% to 92% of further vascular outcomes were not of the same type. Active treatment produced comparable reductions in the risk of vascular outcomes among patients with a broad range of vascular events at entry (relative risk reduction, 25%; P<0.0001 for ischemic stroke; 42%, P=0.0006 for hemorrhagic stroke; 17%, P=0.3 for coronary events; P homogeneity=0.4).</p>
<p><b>Conclusions:</b> Patients with previous vascular events are at high risk of recurrences of the same event. However, because they are also at risk of other vascular outcomes, a broad range of secondary prevention strategies is necessary for their treatment. BP–lowering is likely to be one of the most effective and generalizable strategies across a variety of major vascular events including stroke and myocardial infarction.</p>
Ultrasound is better tolerated than vaginal examination in and before labour
BACKGROUND: Intrapartum ultrasound has been proposed as a method of assessing labour progress but its acceptability has not been comprehensively assessed. AIMS: We evaluated the acceptability of intrapartum ultrasound in women having vaginal examination (VE) and ultrasound (US) assessment (transabdominal (TA) and transperineal (TP)) prior to delivery, with and without regional analgesia (RA). MATERIALS AND METHODS: Women at 24-42 weeks gestation were included in a prospective observational cohort study. The acceptability of digital VE and TP US were assessed pre- and post-examination using the modified validated Wijma Delivery Experience Questionnaire. Acceptability scores ranged 6-36 (6 being most and 36 being least positive) in six domains: positive-trust and relax, negative-harmful to baby, worrying, painful, intrusive. RESULTS: Of 119 women recruited, 104 completed both pre- and post-assessment questionnaires. Eighty-nine per cent of women were nulliparous with median gestation 40 + 2 weeks (25-42+1 ). Thirty-two per cent had RA before assessment, 91% in total. The combined acceptability scores of both negative and positive experiences (6 = most acceptable, 36 = least acceptable) for VE and US pre-assessment were 15 and 7 respectively (P < 0.0001: Mann-Whitney U-test). VE was associated with less positive / more negative domain scoring post-assessment 12 and 6, respectively (P < 0.0001). Although RA made no difference to the perceived experience pre-VE (P = 0.9), post-VE, women with RAs considered VEs more acceptable than those without RA (P = 0.0022). CONCLUSION(S): This is the first study to comprehensively assess the acceptability of VE and intrapartum US. US assessment prior to delivery is more acceptable than VE. RA ameliorated the negative experience of the VE post-assessment
Measurement of the semileptonic branching fraction of the B_s meson
We report a measurement of the inclusive semileptonic branching fraction of the B_s meson using data collected with the BABAR detector in the center-of-mass energy region above the Υ(4S) resonance. We use the inclusive yield of ϕ mesons and the ϕ yield in association with a high-momentum lepton to perform a simultaneous measurement of the semileptonic branching fraction and the production rate of B_s mesons relative to all B mesons as a function of center-of-mass energy. The inclusive semileptonic branching fraction of the B_s meson is determined to be B(B_s→ℓνX)=9.5_(-2.0)^(+2.5)(stat)_(-1.9)^(+1.1)(syst)%, where ℓ indicates the average of e and μ
Study of Y(3S,2S) → ηY(1S) and Y(3S,2S) → π^+π^-Y(1S) hadronic transitions
We study the Υ(3S,2S)→ηΥ(1S) and Υ(3S,2S)→π^+π^-Υ(1S) transitions with 122×10^6Υ(3S) and 100×10^6Υ(2S) mesons collected by the BABAR detector at the PEP-II asymmetric-energy e^+e^- collider. We measure B[Υ(2S)→ηΥ(1S)]=(2.39±0.31(stat.)±0.14(syst.))×10^(-4) and Γ[Υ(2S)→ηΥ(1S)]/Γ[Υ(2S)→π^+π^-Υ(1S)]=(1.35±0.17(stat.)±0.08(syst.))×10^(-3). We find no evidence for Υ(3S)→ηΥ(1S) and obtain B[Υ(3S)→ηΥ(1S)]<1.0×10^(-4) and Γ[Υ(3S)→ηΥ(1S)]/ Γ[Υ(3S)→π^+π^-Υ(1S)]<2.3×10^(-3) as upper limits at the 90% confidence level. We also provide improved measurements of the Υ(2S)-Υ(1S) and Υ(3S)-Υ(1S) mass differences, 562.170±0.007(stat.)±0.088(syst.) MeV/c^2 and 893.813±0.015(stat.)±0.107(syst.) MeV/c^2, respectively
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