Intervention for arch obstruction after the Norwood procedure: Prevalence,associated factors,and practice variability

Objective

Arch obstruction after the Norwood procedure is common and contributes to mortality. We determined the prevalence, associated factors, and practice variability of arch reintervention and assessed whether arch reintervention is associated with mortality.

Mutant C9orf72 human iPSC-derived astrocytes cause non-cell autonomous motor neuron pathophysiology

Mutations in C9orf72 are the most common genetic cause of amyotrophic lateral sclerosis (ALS). Accumulating evidence implicates astrocytes as important non-cell autonomous contributors to ALS pathogenesis, although the potential deleterious effects of astrocytes on the function of motor neurons remains to be determined in a completely humanized model of C9orf72-mediated ALS. Here, we use a human iPSC-based model to study the cell autonomous and non-autonomous consequences of mutant C9orf72 expression by astrocytes. We show that mutant astrocytes both recapitulate key aspects of C9orf72-related ALS pathology and, upon co-culture, cause motor neurons to undergo a progressive loss of action potential output due to decreases in the magnitude of voltage-activated Na⁺ and K⁺ currents. Importantly, CRISPR/Cas-9 mediated excision of the C9orf72 repeat expansion reverses these phenotypes, confirming that the C9orf72 mutation is responsible for both cell-autonomous astrocyte pathology and non-cell autonomous motor neuron pathophysiology.     

New methods for modelling EQ‐5D‐5L value sets: An application to English data

Value sets for the EQ‐5D‐5L are required to facilitate its use in estimating quality‐adjusted life years. An international protocol has been developed to guide the collection of stated preference data for this purpose and has been used to generate EQ‐5D‐5L valuation data for England. The aim of this paper is report the innovative methods used for modelling those data to obtain a value set. Nine hundred and ninety‐six members of the English general public completed time trade‐off (TTO) and discrete choice experiment (DCE) tasks. We estimate models, with and without interactions, using DCE data only, TTO data only, and TTO/DCE data combined. TTO data are interpreted as both left and right censored. Heteroskedasticity and preference heterogeneity between individuals are accounted for. We use Bayesian methods in the econometric analysis. The final model is chosen based on the deviance information criterion (DIC). Censoring and taking account of heteroskedasticity have important effects on parameter estimation. For DCE data only, TTO data only, and DCE/TTO data combined, models with parameters for all dimensions and levels perform best, as judged by the DIC. Taking account of heterogeneity improves fit, and the multinomial model reports the lowest DIC. This paper presents approaches that suit observed characteristics of EQ‐5D‐5L valuation data and recognise respondents' preference heterogeneity. The methods described are potentially relevant to other value set studies.     

Family physician remuneration schemes and specialist referrals: Quasi‐experimental evidence from Ontario,Canada

Understanding how family physicians respond to incentives from remuneration schemes is a central theme in the literature. One understudied aspect is referrals to specialists. Although the theoretical literature has suggested that capitation increases referrals to specialists, the empirical evidence is mixed. We push forward the empirical research on this question by studying family physicians who switched from blended fee‐for‐service to blended capitation in Ontario, Canada. Using several health administrative databases from 2005 to 2013, we rely on inverse probability weighting with fixed‐effects regression models to account for observed and unobserved differences between the switchers and nonswitchers. Switching from blended fee‐for‐service to blended capitation increases referrals to specialists by about 5% to 7% per annum. The cost of specialist referrals is about 7 to 9% higher in the blended capitation model relative to the blended fee‐for‐service. These results are generally robust to a variety of alternative model specifications and matching techniques, suggesting that they are driven partly by the incentive effect of remuneration. Policy makers need to consider the benefits of capitation payment scheme against the unintended consequences of higher referrals to specialists.     

Valuation of EuroQol Five-Dimensional Questionnaire,Youth Version (EQ-5D-Y) and EuroQol Five-Dimensional Questionnaire,Three-Level Version (EQ-5D-3L) Health States: The Impact of Wording and Perspective

Background

Valuations of health states were affected by the wording of the two instruments (EQ-5D-3L and EQ-5D-Y) and by the perspective taken (child or adult).

The Effect of Water Absorption on Acrylic Surface Properties

PURPOSE: The aim of the present study was to determine whether an increased water content during thermal cycling of hot water-treated acrylic was associated with a reduction in surface hardness and an increased opacity or whitening of the surface. MATERIALS AND METHODS: Ten acrylic samples were treated with 30 soak cycles (cycle duration, 24 hours), using warm water (40 degrees C) and an alkaline peroxide tablet (Efferdent control group); a further ten samples were treated with boiling water (100 degrees C) and one Efferdent tablet (experimental group). Indentation hardness of the acrylic specimens was measured prior to and immediately following the completion of the warm and hot water treatments, using an automated micro-indentation system. The hydrated acrylic specimens were then allowed to air dry at room temperature (20 degrees C) and were weighed weekly until they had obtained a constant dry weight. The loss in weight of the acrylic specimens represented the maximum water absorption. RESULTS: The hot water-treated specimens were much whiter than the warm water-treated specimens. The mean reduction in hardness (H(IT)) of the acrylic specimens following the treatment with hot water and alkaline peroxide tablet was 12.9%. Treatment with warm water and alkaline peroxide resulted in a slight increase in mean hardness (2.63%). There was a significant correlation between the water content of the acrylic specimens after treatment and the percentage of change in indentation hardness (r= 0.495, p= 0.026). CONCLUSIONS: The hot water treatment of the acrylic was associated with a significant reduction in hardness. We attribute the whitening and reduction in the hardness of the hot water-treated specimens to absorption of water and a disruption of the acrylic surface structure.