172 research outputs found
A Comparative Examination of the Nature of Change in Macroeconomic Policies
This article examines the impact of economic crises on macroeconomic policies in Ireland in the late 1950s and Sweden in the early 1980s, framed within the context of the policy change literature. Each of these countries? responses to the crises affecting them, tempered as they were by historical and political factors, provides valuable insights into their political economies. These findings enable us to compare and contrast the nature of each crisis and the policy responses adopted. The value of such comparison is in the perspective it offers, contributing to the goal of building a body of increasingly complete explanatory theory (Mahler, 1995).
Toward Evaluation of Disseminated Effects of Medications for Opioid Use Disorder within Provider-Based Clusters Using Routinely-Collected Health Data
Routinely-collected health data can be employed to emulate a target trial when randomized trial data are not available. Patients within provider-based clusters likely exert and share influence on each other’s treatment preferences and subsequent health outcomes and this is known as dissemination or spillover. Extending a framework to replicate an idealized two-stage randomized trial using routinely-collected health data, an evaluation of disseminated effects within provider-based clusters is possible. In this paper, we propose a novel application of causal inference methods for dissemination to retrospective cohort studies in administrative claims data and evaluate the impact of the normality of the random effects distribution for the cluster-level propensity score on estimation of the causal parameters. An extensive simulation study was conducted to study the robustness of the methods under different distributions of the random effects. We applied these methods to evaluate baseline prescription for medications for opioid use disorder among a cohort of patients diagnosed opioid use disorder and adjust for baseline confounders using information obtained from an administrative claims database. We discuss future research directions in this setting to better address unmeasured confounding in the presence of disseminated effects
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Global, regional, and national mortality trends in older children and young adolescents (5–14 years) from 1990 to 2016: an analysis of empirical data
Summary Background From 1990 to 2016, the mortality of children younger than 5 years decreased by more than half, and there are plentiful data regarding mortality in this age group through which we can track global progress in reducing the under-5 mortality rate. By contrast, little is known on how the mortality risk among older children (5–9 years) and young adolescents (10–14 years) has changed in this time. We aimed to estimate levels and trends in mortality of children aged 5–14 years in 195 countries from 1990 to 2016. Methods In this analysis of empirical data, we expanded the United Nations Inter-agency Group for Child Mortality Estimation database containing data on children younger than 5 years with 5530 data points regarding children aged 5–14 years. Mortality rates from 1990 to 2016 were obtained from nationally representative birth histories, data on household deaths reported in population censuses, and nationwide systems of civil registration and vital statistics. These data were used in a Bayesian B-spline bias-reduction model to generate smoothed trends with 90% uncertainty intervals, to determine the probability of a child aged 5 years dying before reaching age 15 years. Findings Globally, the probability of a child dying between the ages 5 years and 15 years was 7·5 deaths (90% uncertainty interval 7·2–8·3) per 1000 children in 2016, which was less than a fifth of the risk of dying between birth and age 5 years, which was 41 deaths (39–44) per 1000 children. The mortality risk in children aged 5–14 years decreased by 51% (46–54) between 1990 and 2016, despite not being specifically targeted by health interventions. The annual number of deaths in this age group decreased from 1·7 million (1·7 million–1·8 million) to 1 million (0·9 million–1·1 million) in 1990–2016. In 1990–2000, mortality rates in children aged 5–14 years decreased faster than among children aged 0–4 years. However, since 2000, mortality rates in children younger than 5 years have decreased faster than mortality rates in children aged 5–14 years. The annual rate of reduction in mortality among children younger than 5 years has been 4·0% (3·6–4·3) since 2000, versus 2·7% (2·3–3·0) in children aged 5–14 years. Older children and young adolescents in sub-Saharan Africa are disproportionately more likely to die than those in other regions; 55% (51–58) of deaths of children of this age occur in sub-Saharan Africa, despite having only 21% of the global population of children aged 5–14 years. In 2016, 98% (98–99) of all deaths of children aged 5–14 years occurred in low-income and middle-income countries, and seven countries alone accounted for more than half of the total number of deaths of these children. Interpretation Increased efforts are required to accelerate reductions in mortality among older children and to ensure that they benefit from health policies and interventions as much as younger children. Funding UN Children\u27s Fund, Bill & Melinda Gates Foundation, United States Agency for International Development
Binary Quasars in the Sloan Digital Sky Survey: Evidence for Excess Clustering on Small Scales
We present a sample of 218 new quasar pairs with proper transverse
separations R_prop < 1 Mpc/h over the redshift range 0.5 < z < 3.0, discovered
from an extensive follow up campaign to find companions around the Sloan
Digital Sky Survey and 2dF Quasar Redshift Survey quasars. This sample includes
26 new binary quasars with separations R_prop < 50 kpc/h (theta < 10
arcseconds), more than doubling the number of such systems known. We define a
statistical sample of binaries selected with homogeneous criteria and compute
its selection function, taking into account sources of incompleteness. The
first measurement of the quasar correlation function on scales 10 kpc/h <
R_prop < 400 kpc/h is presented. For R_prop < 40 kpc/h, we detect an order of
magnitude excess clustering over the expectation from the large scale R_prop >
3 Mpc/h quasar correlation function, extrapolated down as a power law to the
separations probed by our binaries. The excess grows to ~ 30 at R_prop ~ 10
kpc/h, and provides compelling evidence that the quasar autocorrelation
function gets progressively steeper on sub-Mpc scales. This small scale excess
can likely be attributed to dissipative interaction events which trigger quasar
activity in rich environments. Recent small scale measurements of galaxy
clustering and quasar-galaxy clustering are reviewed and discussed in relation
to our measurement of small scale quasar clustering.Comment: 25 pages, 12 figures, 9 tables. Submitted to the Astronomical Journa
Preconception Stress, Birth Weight, and Birth Weight Disparities Among US Women
Objectives. We examined the impact of preconception acute and chronic stressors on offspring birth weight and racial/ethnic birth weight disparities
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Implementation of U.K. Earth system models for CMIP6
We describe the scientific and technical implementation of two models for a core set of
experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6).
The models used are the physical atmosphere-land-ocean-sea ice model HadGEM3-GC3.1 and the
Earth system model UKESM1 which adds a carbon-nitrogen cycle and atmospheric chemistry to
HadGEM3-GC3.1. The model results are constrained by the external boundary conditions (forcing data)
and initial conditions.We outline the scientific rationale and assumptions made in specifying these.
Notable details of the implementation include an ozone redistribution scheme for prescribed ozone
simulations (HadGEM3-GC3.1) to avoid inconsistencies with the model's thermal tropopause, and land use
change in dynamic vegetation simulations (UKESM1) whose influence will be subject to potential biases in
the simulation of background natural vegetation.We discuss the implications of these decisions for
interpretation of the simulation results. These simulations are expensive in terms of human and CPU
resources and will underpin many further experiments; we describe some of the technical steps taken to
ensure their scientific robustness and reproducibility
The Sloan Digital Sky Survey-II Supernova Survey: Search Algorithm and Follow-up Observations
The Sloan Digital Sky Survey-II Supernova Survey has identified a large
number of new transient sources in a 300 sq. deg. region along the celestial
equator during its first two seasons of a three-season campaign. Multi-band
(ugriz) light curves were measured for most of the sources, which include solar
system objects, Galactic variable stars, active galactic nuclei, supernovae
(SNe), and other astronomical transients. The imaging survey is augmented by an
extensive spectroscopic follow-up program to identify SNe, measure their
redshifts, and study the physical conditions of the explosions and their
environment through spectroscopic diagnostics. During the survey, light curves
are rapidly evaluated to provide an initial photometric type of the SNe, and a
selected sample of sources are targeted for spectroscopic observations. In the
first two seasons, 476 sources were selected for spectroscopic observations, of
which 403 were identified as SNe. For the Type Ia SNe, the main driver for the
Survey, our photometric typing and targeting efficiency is 90%. Only 6% of the
photometric SN Ia candidates were spectroscopically classified as non-SN Ia
instead, and the remaining 4% resulted in low signal-to-noise, unclassified
spectra. This paper describes the search algorithm and the software, and the
real-time processing of the SDSS imaging data. We also present the details of
the supernova candidate selection procedures and strategies for follow-up
spectroscopic and imaging observations of the discovered sources.Comment: Accepted for publication in The Astronomical Journal (66 pages, 13
figures); typos correcte
First-Year Spectroscopy for the SDSS-II Supernova Survey
This paper presents spectroscopy of supernovae discovered in the first season
of the Sloan Digital Sky Survey-II Supernova Survey. This program searches for
and measures multi-band light curves of supernovae in the redshift range z =
0.05 - 0.4, complementing existing surveys at lower and higher redshifts. Our
goal is to better characterize the supernova population, with a particular
focus on SNe Ia, improving their utility as cosmological distance indicators
and as probes of dark energy. Our supernova spectroscopy program features
rapid-response observations using telescopes of a range of apertures, and
provides confirmation of the supernova and host-galaxy types as well as precise
redshifts. We describe here the target identification and prioritization, data
reduction, redshift measurement, and classification of 129 SNe Ia, 16
spectroscopically probable SNe Ia, 7 SNe Ib/c, and 11 SNe II from the first
season. We also describe our efforts to measure and remove the substantial host
galaxy contamination existing in the majority of our SN spectra.Comment: Accepted for publication in The Astronomical Journal(47pages, 9
figures
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