Poisson Models with Employer-Employee Unobserved Heterogeneity: An Application to Absence Data

We propose a parametric model based on the Poisson distribution that permits to take into account both unobserved worker and workplace heterogeneity as long as both effects are nested. By assuming that workplace and worker unobserved heterogeneity components follow a gamma and a Dirichlet distribution respectively, we obtain a closed form the unconditional density function. We estimate the model to obtain the determinants of absenteeism using linked employer-employee Canadian data from the Workplace and Employee Survey (2003). Coefficient estimates are interpreted in the framework of the typical labor-leisure model. We show that omitting unobserved heterogeneity on either side of the employment relationship leads to notable biases in the estimated coefficients. In particular, the impact of wages on absences is underestimated in simpler models.Absenteeism, Linked Employer-Employee Data, Employer-Employee Unobserved Heterogeneity, Count Data Models, Dirichlet Distribution

Poisson Models with Employer-Employee Unobserved Heterogeneity: An Application to Absence Data

We propose a parametric model based on the Poisson distribution that permits to take into account both unobserved worker and workplace heterogeneity as long as both effects are nested. By assuming that workplace and worker unobserved heterogeneity components follow a gamma and a Dirichlet distribution respectively, we obtain a closed form for the unconditional density function. We estimate the model to obtain the determinants of absenteeism using linked employer-employee Canadian data from the Workplace and Employee Survey (2003). Coefficient estimates are interpreted in the framework of the typical labor-leisure model. We show that omitting unobserved heterogeneity on either side of the employement relationship leads to notable biases in the estimated coefficients. In particular, the impact of wages on absences is underestimated in simpler models.Absenteeism; Linked Employer-Employee Data; Employer- Employee Unobserved Heterogeneity; Count Data Models; Dirichlet Distribution

Poisson Models with Employer-Employee Unobserved Heterogeneity: an Application to Absence Data

We propose a parametric model based on the Poisson distribution that permits to take into account both unobserved worker and workplace heterogeneity as long as both effects are nested. By assuming that workplace and worker unobserved heterogeneity components follow a gamma and a Dirichlet distribution respectively, we obtain a closed form for the unconditional density function. We estimate the model to obtain the determinants of absenteeism using linked employer-employee Canadian data from the Workplace and Employee Survey (2003). Coefficient estimates are interpreted in the framework of the typical labor-leisure model. We show that omitting unobserved heterogeneity on either side of the employment relationship leads to notable biases in the estimated coefficients. In particular, the impact of wages on absences is underestimated in simpler models

The Benefits Conferred by Radial Access for Cardiac Catheterization Are Offset by a Paradoxical Increase in the Rate of Vascular Access Site Complications With Femoral Access The Campeau Radial Paradox

AbstractObjectivesThe purpose of this study was to assess whether the benefits conferred by radial access (RA) at an individual level are offset by a proportionally greater incidence of vascular access site complications (VASC) at a population level when femoral access (FA) is performed.BackgroundThe recent widespread adoption of RA for cardiac catheterization has been associated with increased rates of VASCs when FA is attempted.MethodsLogistic regression was used to calculate the adjusted VASC rate in a contemporary cohort of consecutive patients (2006 to 2008) where both RA and FA were used, and compared it with the adjusted VASC rate observed in a historical control cohort (1996 to 1998) where only FA was used. We calculated the adjusted attributable risk to estimate the proportion of VASC attributable to the introduction of RA in FA patients of the contemporary cohort.ResultsA total of 17,059 patients were included. At a population level, the VASC rate was higher in the overall contemporary cohort compared with the historical cohort (adjusted rates: 2.91% vs. 1.98%; odds ratio [OR]: 1.48, 95% confidence interval [CI]: 1.17 to 1.89; p = 0.001). In the contemporary cohort, RA patients experienced fewer VASC than FA patients (adjusted rates: 1.44% vs. 4.19%; OR: 0.33, 95% CI: 0.23 to 0.48; p < 0.001). We observed a higher VASC rate in FA patients in the contemporary cohort compared with the historical cohort (adjusted rates: 4.19% vs. 1.98%; OR: 2.16, 95% CI: 1.67 to 2.81; p < 0.001). This finding was consistent for both diagnostic and therapeutic catheterizations separately. The proportion of VASCs attributable to RA in the contemporary FA patients was estimated at 52.7%.ConclusionsIn a contemporary population where both RA and FA were used, the safety benefit associated with RA is offset by a paradoxical increase in VASCs among FA patients. The existence of this radial paradox should be taken into consideration, especially among trainees and default radial operators

Pharmacogenomics of the efficacy and safety of Colchicine in COLCOT

© 2021 The Authors. Circulation: Genomic and Precision Medicine is published on behalf of the American Heart Association, Inc., by Wolters Kluwer Health, Inc. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial License, which permits use, distribution, and reproduction in any medium, provided that the original work is properly cited and is not used for commercial purposes.Background: The randomized, placebo-controlled COLCOT (Colchicine Cardiovascular Outcomes Trial) has shown the benefits of colchicine 0.5 mg daily to lower the rate of ischemic cardiovascular events in patients with a recent myocardial infarction. Here, we conducted a post hoc pharmacogenomic study of COLCOT with the aim to identify genetic predictors of the efficacy and safety of treatment with colchicine. Methods: There were 1522 participants of European ancestry from the COLCOT trial available for the pharmacogenomic study of COLCOT trial. The pharmacogenomic study's primary cardiovascular end point was defined as for the main trial, as time to first occurrence of cardiovascular death, resuscitated cardiac arrest, myocardial infarction, stroke, or urgent hospitalization for angina requiring coronary revascularization. The safety end point was time to the first report of gastrointestinal events. Patients' DNA was genotyped using the Illumina Global Screening array followed by imputation. We performed a genome-wide association study in colchicine-treated patients. Results: None of the genetic variants passed the genome-wide association study significance threshold for the primary cardiovascular end point conducted in 702 patients in the colchicine arm who were compliant to medication. The genome-wide association study for gastrointestinal events was conducted in all 767 patients in the colchicine arm and found 2 significant association signals, one with lead variant rs6916345 (hazard ratio, 1.89 [95% CI, 1.52-2.35], P=7.41×10-9) in a locus which colocalizes with Crohn disease, and one with lead variant rs74795203 (hazard ratio, 2.51 [95% CI, 1.82-3.47]; P=2.70×10-8), an intronic variant in gene SEPHS1. The interaction terms between the genetic variants and treatment with colchicine versus placebo were significant. Conclusions: We found 2 genomic regions associated with gastrointestinal events in patients treated with colchicine. Those findings will benefit from replication to confirm that some patients may have genetic predispositions to lower tolerability of treatment with colchicine.info:eu-repo/semantics/publishedVersio

Seismic energy propagation in highly scattering environments and constraints on lunar interior structure from the scattered signals of the Apollo passive seismic experiment

Meteoroid impacts over hundreds of millions to billions of years can produce a highly fractured and heterogeneous megaregolith layer on planetary bodies such as the Moon that lack effective surface recycling mechanisms. The energy from seismic events occurring on these bodies undergoes scattering in the fractured layer(s) and this process generates extensive coda wave trains that follow major seismic wave arrivals. These long coda trains can obscure the secondary crustal, mantle or core phases that are often crucial in assessing the interior structure of these planetary bodies when using more traditional seismological analyses. However, the decay properties of these codas are affected by the interior velocity, intrinsic attenuation and scattering structure of the planet or moon. As such, these decay properties can contain valuable information regarding these aspects of interior structure. This thesis provides the first systematic analysis of scattering in the Apollo Passive Seismic Experiment dataset, demonstrating that scattering in the Moon occurs over a wide range of frequencies, and dominantly in the near-surface megaregolith that comprises many more small scale heterogeneities than large ones. I also present a new numerical modeling technique (referred to as PHONON1D) that models seismic energy propagation and integrates high levels of scattering. Using this method, I investigate the effects of various velocity, scattering and intrinsic attenuation structures on the scattered coda. Results show that the main controls on the coda generation and decay times are the seismic velocity profile, attenuation levels, and the number density of scatterers. Thus these properties can be assessed by comparing predicted synthetic seismic coda with those observed in the Apollo Passive Seismic Experiment data. Finally, I use the PHONON1D method to show that locations within young and large impact basins, away from the edges, have the potential to minimize the scattering observed in the recorded seismic signals. These locations would be ideal for the emplacement of future seismic surveys on the lunar surface.Science, Faculty ofEarth, Ocean and Atmospheric Sciences, Department ofGraduat

Modélisation et estimation des effets individuels et d’entreprise avec des données de panel : une application aux parcs de véhicules

Dans cet article, nous proposons une analyse détaillée de la modélisation et de l’estimation des distributions d’accidents de véhicules appartenant à un parc de véhicules. L’analyse tient compte simultanément des effets véhicules et de parcs de véhicules avec des données de panel. La distribution des accidents peut être affectée par des facteurs observables et non observables. Les facteurs non observables sont modélisés comme des effets aléatoires.In this article, we propose a detailed analysis of the modeling and estimation of accident distributions of vehicles belonging to a fleet. This analysis uses panel data to account simultaneously for vehicle as well as fleet effects. The distribution of accidents can be affected by both observable and non-observable factors. Nonobservable factors are modeled as random effects

A Genetic Algorithm for Vehicle Routing with Backhauling

International audienc