Consumer-Phase Salmonella enterica serovar Enteritidis Risk Assessment for Egg-Containing Food Products

We describe a one-dimensional probabilistic model of the role of domestic food handling behaviors on salmonellosis risk associated with the consumption of eggs and egg-containing foods. Six categories of egg-containing foods were defined based on the amount of egg contained in the food, whether eggs are pooled, and the degree of cooking practiced by consumers. We used bootstrap simulation to quantify uncertainty in risk estimates due to sampling error, and sensitivity analysis to identify key sources of variability and uncertainty in the model. Because of typical model characteristics such as nonlinearity, interaction between inputs, thresholds, and saturation points, Sobol's method, a novel sensitivity analysis approach, was used to identify key sources of variability. Based on the mean probability of illness, examples of foods from the food categories ranked from most to least risk of illness were: (1) home-made salad dressings/ice cream; (2) fried eggs/boiled eggs; (3) omelettes; and (4) baked foods/breads. For food categories that may include uncooked eggs (e.g., home-made salad dressings/ice cream), consumer handling conditions such as storage time and temperature after food preparation were the key sources of variability. In contrast, for food categories associated with undercooked eggs (e.g., fried/soft-boiled eggs), the initial level of Salmonella contamination and the log10 reduction due to cooking were the key sources of variability. Important sources of uncertainty varied with both the risk percentile and the food category under consideration. This work adds to previous risk assessments focused on egg production and storage practices, and provides a science-based approach to inform consumer risk communications regarding safe egg handling practices.     

HOW DO ELECTORAL SYSTEMS AFFECT FISCAL POLICY? EVIDENCE FROM CANTONAL PARLIAMENTS, 1890–2000

Using a new data set on Swiss cantons since 1890, we analyze how the adoption of proportional representation affects fiscal policy. In line with economic theory, we show that proportional systems shift spending toward broad goods (like education and welfare benefits) but decrease spending on geographically targetable goods (like roads). We find little evidence that proportional representation increases the overall size of government. An analysis of the underlying theoretical mechanisms reveals that proportional representation increases electoral turnout, left‐wing representation, and political fragmentation. These changes in political representation explain a substantial share of the rise in education spending, but a small share of the rise in welfare spending or the decline in road expenditures.     

Daily Variation in Adolescents' Sleep,Activities, and Psychological Well‐Being

The daily diary method was used to examine the daily dynamics of adolescent sleep time, activities, and psychological well‐being among an ethnically diverse sample of over 750 adolescents approximately 14–15 years of age. Studying and stressful demands during the day were modestly but consistently associated with less sleep that evening. Receiving less sleep at night, in turn, was modestly but consistently related to higher levels of anxiety, depressive feelings, and fatigue during the following day. In addition, the daily variability in adolescents' sleep time was notable and just as important for the youths' average levels of daily psychological well‐being as was the average amount of time spent sleeping each night. A small number of ethnic and gender differences emerged in the dynamics of adolescent sleep, activities, and well‐being. Discussion focuses on the importance of examining variability in adolescents' sleep behaviors in order to better understand the implications of sleep for adolescent well‐being and development.     

Employment and the Risk of Domestic Abuse Among Low‐Income Women

This paper uses data from 2 randomized evaluations of welfare‐to‐work programs—the Minnesota Family Investment Program and the National Evaluation of Welfare‐to‐Work Strategies—to estimate the effect of employment on domestic abuse among low‐income single mothers. Unique to our analysis is the application of a 2‐stage least squares method, in which random assignment enables us to control for omitted characteristics that might otherwise confound the association between employment and domestic abuse. We find that increased maternal employment decreases subsequent reports of domestic abuse in both studies. In the Minnesota Family Investment Program—a program with an enhanced income disregard that allowed welfare mothers to keep a portion of their welfare income as earnings rose—an increase in household incomes appears to have contributed to reductions in reports of domestic abuse.     

FAMILY STRUCTURE, CLOSENESS TO RESIDENTIAL AND NONRESIDENTIAL PARENTS, AND PSYCHOLOGICAL DISTRESS IN EARLY AND MIDDLE ADOLESCENCE

American adolescents currently live in a variety of different family structures, with the vast majority of adolescents living in intact, blended, divorced, and never-married families. Previous research shows that family structure correlates both with the quality of parent–adolescent relationships and adolescent psychological distress. The quality of parent–adolescent relationships also correlates with adolescent distress. This research hypothesizes that the observed differences in adolescent distress across family structure might result from differences in the quality of parent–adolescent relationships across family structure. Analyses, using data on 1,443 youth in early and middle adolescence from the National Longitudinal Survey of Youth (NLSY), indicate that when the variations in both the quality of parent–adolescent relationships and background characteristics across family structure are controlled, the association between family structure and adolescent psychological distress is significantly reduced. Further analyses revealed that the quality of residential parent–adolescent relationships explained the most variation in adolescent psychological distress. The quality of relationships with nonresidential fathers only had a significant association with adolescent psychological distress for adolescents in blended families.     

Characterising the Perceived Risks and Benefits of Some Health Issues

Previous work on perceived risk, particularly a study by Fischhoff et al. (1978), is critically examined with reference to its applicability to specific health related issues. Judgments were obtained from 159 subjects of 15 health-related items in terms of perceived risk, benefit, and a number of risk characteristics based on the Fischhoff et al. research. In addition, demographic details concerning sex of respondent, seat belt usage, smoking status, and birth order were collected. Using regression analyses it was found that the direction of the risk-benefit relationship was dependent on the issue being judged. Risk was found to be better explained by ratings of likelihood of mishap and likelihood of death as a consequence of mishap. Benefit was poorly explained by the risk characteristics and demographic data. However, subject group characteristics were shown to be important influences on risk and benefit perception in certain situations. The implications of these results for understanding behavioral decisions involving risk in relation to specific activities are discussed.     

Medical students' and tutors' experiences of directed and self-directed learning programs in evidence-based medicine: a qualitative evaluation accompanying a randomized controlled trial

This qualitative study aims to interpret the results of a randomized controlled trial comparing two educational programs (directed learning and self-directed learning) in evidence-based medicine (EBM) for medical students at the University of Oslo from 2002 to 2003. There is currently very little comparative educational research in this field. In the trial, no statistically significant differences between the study groups were shown for any outcomes considered (EBM knowledge, skills, and attitudes). Further analysis suggests that main reason for the negative trial results was that the majority of students learned equally effectively, whichever program they received, although implementation of the educational programs was not complete because of varying attendance. This study illustrates a stepwise evaluation model that might be useful in evaluating other socially complex interventions.     

Dempster's combination rule and sufficient statistics

In his articles (1966-1968) concerning statistical inference based on lower and upper probabilities, Dempster refers to the connection between Fisher's fiducial argument and his own ideas of statistical inference. Dempster's main concern however focuses on the “Bayesian” aspects of his theory and not on an elaboration of the relation between Fisher's and his ideas. This article attempts to work out the connection between those two approaches and focuses primarily on the question, whether Dempster's combination rule, his upper and lower probabilty based on sufficient statistics and inference based on sufficient statistics in Fisher's sense are consistent. To be adequate to Fisher's reasoning, we deal with absolutely continuous, one parametric families of distributions.This is certainly not the usual assumption in context with Dempster's theory and implies a normative but straightforward definition concerning the underlying conditional distribution; this definition however is done in Dempster's spirit as can be seen from his articles, (1966, 1968,a,b). Under those assumptions it can be shown that - similar to Lindley's results concerning consistency in fiducial reasoning (1958) - the combination rule, Dempster's procedure based on sufficient statistics and fiducial inference by sufficient statistics agree iff the parametric family under consideration can be transformed to location parameter form.