The effects of covariate adjustment in generalized linear models

Results from classical linear regression regarding the effects of covariate adjustment, with respect to the issues of confounding, the precision with which an exposure effect can be estimated, and the efficiency of hypothesis tests for no treatment effect in randomized experiments, are often assumed to apply more generally to other types of regression models. In this paper results pertaining to several generalized linear models involving a dichotomous response variable are given, demonstrating that with respect to the issues of confounding and precision, for models having a linear or log link function the results of classical linear regression do generally apply, whereas for other models, including those having a logit, probit, log-log, complementary log-log, or generalized logistic link function, the results of classical linear regression do not always apply. It is also shown, however, that for any link function, covariate adjustment results in improved efficiency of hypothesis tests for no treatment effect in randomized experiments, and hence that the classical linear regression results regarding efficiency do apply for all models having a dichotomous response variable.     

Transdiagnostic mechanisms involved in nonsuicidal self-injury,risky drinking and disordered eating: Impulsivity,emotion regulation and alexithymia

Abstract

Objective: The aim of the present study was to explore common and differential relationships between nonsuicidal self-injury (NSSI), risky drinking, and disordered eating attitudes and impulsivity, emotion dysregulation, and alexithymia. Methods: We investigated these associations in a sample of 951 college students (79.4% female, Mage = 21.86?years) by means of self-report questionnaires assessing the constructs of interest. Results: Overall, 28% of the students reported a history of NSSI, one third engaged in risky drinking, and less than 5% reported disordered eating symptoms. Negative urgency and difficulties in emotion regulation were both related to each of the three behaviors and can be considered as common transdiagnostic mechanisms. Conclusions: We discuss the implications of transdiagnostic mechanisms involved in these three dysregulated behaviors with respect to their assessment and treatment in college counseling settings.     

Risk Mapping of Groundwater‐Drawdown‐Induced Land Subsidence in Heterogeneous Soils on Large Areas

Groundwater leakage into subsurface constructions can cause reduction of pore pressure and subsidence in clay deposits, even at large distances from the location of the construction. The potential cost of damage is substantial, particularly in urban areas. The large‐scale process also implies heterogeneous soil conditions that cannot be described in complete detail, which causes a need for estimating uncertainty of subsidence with probabilistic methods. In this study, the risk for subsidence is estimated by coupling two probabilistic models, a geostatistics‐based soil stratification model with a subsidence model. Statistical analyses of stratification and soil properties are inputs into the models. The results include spatially explicit probabilistic estimates of subsidence magnitude and sensitivities of included model parameters. From these, areas with significant risk for subsidence are distinguished from low‐risk areas. The efficiency and usefulness of this modeling approach as a tool for communication to stakeholders, decision support for prioritization of risk‐reducing measures, and identification of the need for further investigations and monitoring are demonstrated with a case study of a planned tunnel in Stockholm.     

Individual rights and collective obligation. Compulsory intervention towards substance abusers in Norwegian social law

This article focuses on an important duality in the modern welfare state: the will to help our fellow citizens through institutionalized welfare policies, and the danger of violating individual liberty and integrity. Individual rights of self-determination and integrity are important values of the liberal constitutional government (the Rechtstaat). Our collective ethical obligation to help those in need is an important value of the welfare state. With respect to compulsory intervention towards adult and under-age substance abusers, the possible tensions between these values are particularly visible. The legal foundation for such efforts in Norwegian social law is discussed with regard to different ethical and moral principles. The main questions are how compulsory interventions are justified and how different principles are weighted in positive law. The ethical principles of collective obligation and the moral principle of individual rights are differently balanced in the Child Care Service Act and the Social Service Act. Both acts, however, expose the problematic combination of solving social problems by the use of force and securing individual autonomy and integrity.     

A study on IUD retention by curve-fitting

In order to estimate the demographic impact of IUD, there is a need for estimating IUD retention rates beyond the period of actual observation. This article describes a mixed exponential function for this purpose. With this function of IUD retention, it is possible to estimate the “life expectancy” and “half-life” of an IUD. Another important concept is the “cut-off date”, introduced in estimating the “life expectancy” because in practice no IUD will be worn by a woman forever.     

Employee correlates of sickness presence: A study across four European countries

The model of sickness presence (SP) proposed by Aronsson and Gustafsson consists of two parts. The first postulates SP as an employee's reaction to his/her general state of health, and as depending on employee correlates relating to the individual and the job. The second proposes longitudinal relationships between SP and future health. The present study is the first to test the first part of the model outside Scandinavia. Positive sickness presence factors studied were work involvement and job satisfaction; negative presence factors were financial household contribution, time pressure at work, and perceived job insecurity. Control variables were general health, age, gender and autonomy. Data (N=2348) were gathered from a total of 110 organizations in four European countries (Belgium, Spain, Sweden and the UK) with differing welfare state regime, degree of employment protection, labour market and sickness absence-related indicators. The data were analysed by hierarchical multiple regression per country. The findings partially confirmed the Aronsson and Gustafsson model. In all countries, employee general health status was a prerequisite of SP, and time pressure at work related to SP. In Sweden and the UK, job satisfaction related to SP. In the UK, work involvement related to SP.     

Gender,power and office politics

Abstract

This interpretative study explores the experiences of Taiwanese female clerical workers as they deal with office politics. A hermeneutical phenomenology is used to describe and interpret the participants' experiences. The study shows that powerlessness and frustration result from: (1) structural barriers; (2) behavioral barriers; and (3) accommodation and rationalization. This study has implications for research and practice in international area of women's studies and for the field of international career development education.     

Moments of order statistics from a non-overlapping mixture model with applications to truncated laplace distribution

We employ two different approaches to derive single and product moments of order statistics from a truncated Laplace distribution. A direct evaluation method establishes recurrence relations whereas the more general non-overlapping mixture model incorporates the truncated Laplace distribution as a special case. The results are thereafter applied to estimate location and scale parameters of such distributions.     

Spin doctors in the spotlight: Effects of strategic press and publicity coverage on perceptions of political PR

News media often engage in strategy framing when covering politics, including strategic press and publicity coverage coined to express the focus on the media's role in the game of politics, as well as politicians’ calculated publicity and public relations efforts in relation to the media. This study examines the effect of strategic press and publicity coverage on perceptions of political PR once its practitioners and their publicity efforts have become the object of reporting. Drawing on data from two experiments (n = 863), we show how political PR professionals have themselves little to gain from becoming part of the story.     

Risk-Based Analysis of the Danish Pork Salmonella Program: Past and Future

The Danish pork Salmonella control program was initiated in 1993 in response to a prominent pork-related outbreak in Copenhagen. It involved improved efforts at slaughter hygiene (postharvest) and on-farm (preharvest) surveillance and control. After 10 years, 95 million Euros, significant reductions in seropositive herds, Salmonella positive carcasses, and pork-attributable human cases (PAHC), questions have arisen about how best to continue this program. The objective of this study was to provide some analysis and information to address these questions. The methods used include a computer simulation model constructed of a series of Excel workbooks, one for each simulated year and scenario ( http://www.ifss.iastate/DanSalmRisk ). Each workbook has three modules representing the key processes affecting risk: seropositive pigs leaving the farm (Production), carcass contamination after slaughter (Slaughter), and PAHC of Salmonella (Attribution). Parameter estimates are derived from an extensive farm-to-fork database collected by industry and government and managed by the Danish Zoonosis Centre ( http://www.food.dtu.dk ). Retrospective (1994–2003) and prospective (2004–2013) simulations were evaluated. The retrospective simulations showed that, except for the first few years (1994–1998), the on-farm program had minimal impact in reducing the number of positive carcasses and PAHC. Most of the reductions in PAHC up to 2003 were, according to this analysis, due to various improvements in abattoir processes. Prospective simulations showed that minimal reductions in human health risk (PAHC) could be achieved with on-farm programs alone. Carcass decontamination was shown as the most effective means of reducing human risk, reducing PAHC to about 10% of the simulated 2004 level.