Estimating the Causal Effect of Low Tidal Volume Ventilation on Survival in Patients with Acute Lung Injury

Acute lung injury (ALI) is a condition characterized by acute onset of severe hypoxemia and bilateral pulmonary infiltrates. ALI patients typically require mechanical ventilation in an intensive care unit. Low tidal volume ventilation (LTVV), a time-varying dynamic treatment regime, has been recommended as an effective ventilation strategy. This recommendation was based on the results of the ARMA study, a randomized clinical trial designed to compare low vs. high tidal volume strategies (The Acute Respiratory Distress Syndrome Network, 2000) . After publication of the trial, some critics focused on the high non-adherence rates in the LTVV arm suggesting that non-adherence occurred because treating physicians felt that deviating from the prescribed regime would improve patient outcomes. In this paper, we seek to address this controversy by estimating the survival distribution in the counterfactual setting where all patients assigned to LTVV followed the regime. Inference is based on a fully Bayesian implementation of Robins' (1986) G-computation formula. In addition to re-analyzing data from the ARMA trial, we also apply our methodology to data from a subsequent trial (ALVEOLI), which implemented the LTVV regime in both of its study arms and also suffered from non-adherence.     

A Bayesian analysis of clustered discrete and continuous outcomes

Many study designs yield a variety of outcomes from each subject clustered within an experimental unit. When these outcomes are of mixed data types, it is challenging to jointly model the effects of covariates on the responses using traditional methods. In this paper, we develop a Bayesian approach for a joint regression model of the different outcome variables and show that the fully conditional posterior distributions obtained under the model assumptions allow for estimation of posterior distributions using Gibbs sampling algorithm.     

Emotion regulation from infancy to toddlerhood: Individual and group trajectories of full-term and very-low-birthweight preterm infants

Adaptive emotion regulation begins with infants operating jointly with their parents to regulate their emotions, which fosters the development of independent regulation. Little is known about when or how this transition occurs, or the impact of factors such as parental availability or premature birth status. The current study examined the use of self-soothing, attentional distraction, and dyadic regulation in full-term and healthy very-low-birthweight (VLBW) preterm infant-mother dyads at 5 ½, 12, and 18 months of age. At 5 ½ months, dyads participated in the Still-Face procedure. At 12 and 18 months, dyads participated in two free-play interactions, a puzzle task, and an interference task. Emotion regulation behaviors were coded using two systematic, observational systems. Results indicated that infants used less self-soothing and attentional distraction and more dyadic regulation as they aged. Increased use of self-soothing at earlier ages predicted increased use of dyadic regulation at subsequent ages. Toddlers used more independent, attention-seeking, and escape behavior during periods of maternal unavailability. There were no significant differences between full-term and VLBW/preterm toddlers’ emotion regulation behaviors. Results from the current study contribute to the understanding of normative development of emotion regulation and the risk associated with prematurity.     

Development of a First Peoples-led cultural capability measurement tool: A pilot study with midwifery students

Background

Midwives have a central role in closing the gap in health inequalities between Australias’ First Peoples and other childbearing women. The Aboriginal and Torres Strait Islander Health Curriculum Framework (The Framework) identifies five core cultural capabilities (respect, communication, safety and quality, reflection and advocacy) to foster culturally safe health care.

‘Our world was made by nature’: constructions of spontaneous order

ABSTRACT

This article explores the concepts of spontaneity and spontaneous order, in particular their deployment by Friedrich Hayek and Karl Polanyi. Although in many respects these thinkers were poles apart, the article identifies a point of convergence. They both mobilize the concept of spontaneity in a manner that naturalizes a particular social process: for Hayek, the market economy, for Polanyi, society’s protective movement that arises in reaction against the market economy. To contextualize the uses of spontaneity by Hayek and Polanyi, I trace its evolution, with reference to Leibniz, Mandeville, and the thinkers of the Scottish Enlightenment. Having sketched the ways in which earlier thinkers understood spontaneity, I turn finally to Hayek and Polanyi. I argue that their invocations of spontaneity and spontaneous order contribute to a downplaying of relations of domination and exploitation. While Hayek sees the market system as the exemplar of spontaneous order, for Polanyi, the concept of spontaneity underpins his belief that the protective countermovement is a ‘natural’ reaction to the evils of market society; as such, power relations pass beneath the radar.     

One Size Fits All? The Validity of a Composite Poverty Index Across Urban and Rural Households in South Africa

Composite indices have been prominently used in poverty research. However, validity of these indices remains subject to debate. This paper examines the validity of a common type of composite poverty indices using data from a cross-sectional survey of 2477 households in urban and rural KwaZulu-Natal, South Africa. Multiple-group comparisons in structural equation modelling were employed for testing differences in the measurement model across urban and rural groups. The analysis revealed substantial variations between urban and rural respondents both in the conceptualisation of poverty as well as in the weights and importance assigned to individual poverty indicators. The validity of a ‘one size fits all’ measurement model can therefore not be confirmed. In consequence, it becomes virtually impossible to determine a household’s poverty level relative to the full sample. Findings from our analysis have important practical implications in nuancing how we can sensitively use composite poverty indices to identify poor people.     

If You Go Down to the Woods Today: Infants’ Distress During a Teddy Bear's Picnic in Relation to Peer Relations and Later Emotional Problems

Infants’ emotional reactions to an unusual event were assessed at a simulated birthday party during which two costumed characters enacted a Teddy Bear's Picnic. Two hundred and fifty‐eight firstborn infants in a representative British community sample were observed at a mean age of 12.8 months in the presence of their parents and other participating families, in a laboratory sitting room decorated with balloons and banners. The picnic scenario was followed by free play with the other participating infants. At a mean of 36 months of age, mothers, fathers, and another informant who knew the child well completed the Child Behaviour Check List (CBCL). The majority of infants showed no vocal distress during the picnic scenario. A minority of infants expressed strong distress, which was correlated with elevated heart rate and production of cortisol. Infants who were not distressed were more likely to direct social behavior to their peers and especially likely to use physical force against peers. In comparison with strongly distressed and nondistressed infants, those who had shown mild distress during the picnic scenario were least likely to manifest later emotional problems. This pattern was particularly marked for boys. Taken together, the findings indicate that infants’ strong distress during naturalistic encounters that are meant to be entertaining can suppress sociability and might indicate risk for subsequent emotional problems.