7,495 research outputs found

    Deep brain and cortical stimulation for epilepsy

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    Background : Despite optimal medical treatment, including epilepsy surgery, many epilepsy patients have uncontrolled seizures. In the last decades, interest has grown in invasive intracranial neurostimulation as a treatment for these patients. Intracranial stimulation includes both deep brain stimulation (DBS) (stimulation through depth electrodes) and cortical stimulation (subdural electrodes). Objectives : To assess the efficacy, safety and tolerability of deep brain and cortical stimulation for refractory epilepsy based on randomized controlled trials. Search methods : We searched PubMed (6 August 2013), the Cochrane Epilepsy Group Specialized Register (31 August 2013), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 7 of 12) and reference lists of retrieved articles. We also contacted device manufacturers and other researchers in the field. No language restrictions were imposed. Selection criteria : Randomized controlled trials (RCTs) comparing deep brain or cortical stimulation to sham stimulation, resective surgery or further treatment with antiepileptic drugs. Data collection and analysis : Four review authors independently selected trials for inclusion. Two review authors independently extracted the relevant data and assessed trial quality and overall quality of evidence. The outcomes investigated were seizure freedom, responder rate, percentage seizure frequency reduction, adverse events, neuropsychological outcome and quality of life. If additional data were needed, the study investigators were contacted. Results were analysed and reported separately for different intracranial targets for reasons of clinical heterogeneity. Main results : Ten RCTs comparing one to three months of intracranial neurostimulation to sham stimulation were identified. One trial was on anterior thalamic DBS (n = 109; 109 treatment periods); two trials on centromedian thalamic DBS (n = 20; 40 treatment periods), but only one of the trials (n = 7; 14 treatment periods) reported sufficient information for inclusion in the quantitative meta-analysis; three trials on cerebellar stimulation (n = 22; 39 treatment periods); three trials on hippocampal DBS (n = 15; 21 treatment periods); and one trial on responsive ictal onset zone stimulation (n = 191; 191 treatment periods). Evidence of selective reporting was present in four trials and the possibility of a carryover effect complicating interpretation of the results could not be excluded in 4 cross-over trials without any washout period. Moderate-quality evidence could not demonstrate statistically or clinically significant changes in the proportion of patients who were seizure-free or experienced a 50% or greater reduction in seizure frequency (primary outcome measures) after 1 to 3 months of anterior thalamic DBS in (multi) focal epilepsy, responsive ictal onset zone stimulation in (multi) focal epilepsy patients and hippocampal DBS in (medial) temporal lobe epilepsy. However, a statistically significant reduction in seizure frequency was found for anterior thalamic DBS (-17.4% compared to sham stimulation; 95% confidence interval (CI) -32.1 to -1.0; high-quality evidence), responsive ictal onset zone stimulation (-24.9%; 95% CI -40.1 to 6.0; high-quality evidence)) and hippocampal DBS (-28.1%; 95% CI -34.1 to -22.2; moderate-quality evidence). Both anterior thalamic DBS and responsive ictal onset zone stimulation do not have a clinically meaningful impact on quality life after three months of stimulation (high-quality evidence). Electrode implantation resulted in asymptomatic intracranial haemorrhage in 3% to 4% of the patients included in the two largest trials and 5% to 13% had soft tissue infections; no patient reported permanent symptomatic sequelae. Anterior thalamic DBS was associated with fewer epilepsy-associated injuries (7.4 versus 25.5%; P = 0.01) but higher rates of self-reported depression (14.8 versus 1.8%; P = 0.02) and subjective memory impairment (13.8 versus 1.8%; P = 0.03); there were no significant differences in formal neuropsychological testing results between the groups. Responsive ictal-onset zone stimulation was well tolerated with few side effects but SUDEP rate should be closely monitored in the future (4 per 340 [= 11.8 per 1000] patient-years; literature: 2.2-10 per 1000 patient-years). The limited number of patients preclude firm statements on safety and tolerability of hippocampal DBS. With regards to centromedian thalamic DBS and cerebellar stimulation, no statistically significant effects could be demonstrated but evidence is of only low to very low quality. Authors' conclusions : Only short term RCTs on intracranial neurostimulation for epilepsy are available. Compared to sham stimulation, one to three months of anterior thalamic DBS ((multi) focal epilepsy), responsive ictal onset zone stimulation ((multi) focal epilepsy) and hippocampal DBS (temporal lobe epilepsy) moderately reduce seizure frequency in refractory epilepsy patients. Anterior thalamic DBS is associated with higher rates of self-reported depression and subjective memory impairment. SUDEP rates require careful monitoring in patients undergoing responsive ictal onset zone stimulation. There is insufficient evidence to make firm conclusive statements on the efficacy and safety of hippocampal DBS, centromedian thalamic DBS and cerebellar stimulation. There is a need for more, large and well-designed RCTs to validate and optimize the efficacy and safety of invasive intracranial neurostimulation treatments

    Hedonic Wage Equilibrium: Theory, Evidence and Policy

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    We examine theoretically and empirically the properties of the equilibrium wage function and its implications for policy. Our emphasis is on how the researcher approaches economic and policy questions when there is labor market heterogeneity leading to a set of wages. We focus on the application where hedonic models have been most successful at clarifying policy relevant outcomes and policy effects, that of the wage premia for fatal injury risk. Estimates of the overall hedonic locus we discuss imply the so-called value of a statistical life (VSL) that is useful as the benefit value in a cost-effectiveness calculation of government programs to enhance personal safety. Additional econometric results described are the multiple dimensions of heterogeneity in VSL, including by age and consumption plans, the latent trait that affects wages and job safety setting choice, and family income. Simulations of hedonic market outcomes are also valuable research tools. To demonstrate the additional usefulness of giving detail to the underlying structure we not only develop the issue of welfare comparisons theoretically but also illustrate how numerical simulations of the underlying structure can also be informative. Using a reasonable set of primitives we see that job safety regulations are much more limited in their potential for improving workplace safety efficiently compared to mandatory injury insurance with experience rated premiums. The simulations reveal how regulations incent some workers to take more dangerous jobs, while workers’ compensation insurance does not (or less so).hedonic labor market equilibrium, VSL, panel data, job safety, OSHA, quantile regression, workers’ compensation insurance

    Subjective well-being and mortality in Chinese oldest old

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    The present study investigates the relationship between subjective well-being (SWB) and mortality risk, using a large sample (N=7852) from the Chinese Longitudinal Healthy Longevity Study (age range 80-105) conducted in 2000 and 2002. Initially, we intended to contribute to the understanding of system relations between SWB, mortality risk, and unobserved heterogeneity by treating SWB as an endogenous variable, using a multi-process model. However, failure to identify unobserved heterogeneity in the mortality equation prevents us from employing this model. Given this limitation, the study examines three issues. First, we argue that the mortality model with duration dependency on the age of the study subjects is specified and that the model with duration dependency on time since the interview is misspecified. Second, we address problems associated with the identification of unobserved heterogeneity in the mortality equation. Third, we examine the association between SWB and mortality risk in the Chinese oldest old as well as the risk pattern by gender, without considering unobserved heterogeneity. We find that SWB is not a significant predictor of mortality risk when we control for socio-demographic characteristics and health status. Health plays a very important role in the relationship between SWB and mortality risk in the oldest old. Gender differences in the predictive pattern of SWB on this risk are negligible in the sample.China, mortality

    THE MENTAL HEALTH OF MOTHERS AND FATHERS BEFORE AND AFTER COHABITATION AND MARITAL DISSOLUTION

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    Using data from years one and three of the Fragile Families and Child Well-being Study, changes in depressive and anxious symptoms are compared for mothers and fathers who: 1) dissolve a cohabitating union versus remain intact; 2) dissolve a marital union versus remain intact; and 3) dissolve a cohabiting as compared to a marital union. In order to take into account potential sources of third variable bias from selection factors that differentiate those who are in cohabitations from those who are in marriages, mothers and fathers were matched on several sociodemographic control variables that research has demonstrated to be related to union formation and mental health outcomes. Results indicated that fathers who dissolve cohabitating or marital unions have greater increases in depressive and anxious symptoms over time than those who remain in their unions. In contrast, mothers increased in depressive and anxious symptoms, regardless of the type or stability of the union. For both mothers and fathers, no differences were found in change in mental health by type of union dissolution. In this low income sample of parents, results suggest that the impact of cohabitation and marital dissolution on mental health are similar in magnitude.Depression, fragile families, marriage, cohabitation, income, mental health

    Evaluating center‐specific long‐term outcomes through differences in mean survival time: Analysis of national kidney transplant data

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149342/1/sim8076.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149342/2/sim8076_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149342/3/SIM_8076-Supp-0002-Web_Supple.pd

    Maternal smoking during pregnancy and birthweight - A propensity score matching approach

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    There is accumulated evidence of the existence of a deleterious effect of smoking on birth outcomes. Understanding the effect of smoking on pregnancy is a critical issue because of the public policy implications for dissuading maternal smoking. We explore this issue by using the propensity score method and compare that with parametric estimators. First we estimate the treatment effect of smoking during pregnancy on different birth outcomes. Then, we extend the method to the case of the multi-treatment "intensity of smoking". The deleterious effect of smoking is found robust to the different estimation methods used.Smoking, birth outcomes, causal effects, propensity score and matching
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