An improved comorbidity summary score for measuring disease burden and predicting mortality with applications to two national cohorts

Abstract

Research involving administrative healthcare data to study patient outcomes requires the investigator to account for the patient’s disease burden in order to reduce the potential for biased results. Here we develop a comorbidity summary score based on variable importance measures derived from several statistical and machine learning methods and show it has superior predictive performance to the Elixhauser and Charlson indices when used to predict 1-year, 5-year, and 10-year mortality. We used two large Veterans Administration cohorts to develop and validate the summary score and compared predictive performance using the area under ROC curve (AUC) and the Brier score.     

Handling cause of death in equivocal cases using the em algorithm

The statistical analysis of animal bioassays fore carcinogenicity often involves utilizing the cause of death of each animal. There is considerable disagreement among veterinary pathologists as to the reliability of cause of death information. Recent recommendations for assigning cause of death in animal studies have allowed for uncertainty on the part of the pathologist. This has given rise to data that contain acknowledged equivocal cases with respect to cause of death. The present paper proposes a method for incorporating these equiYocal cases into an existing estimation procedure that requires distinguishing between tumors that caused death and those that did not.     

The Appropriateness of Some Common Procedures for Testing the Equality of Two Independent Binomial Populations

For testing the equality of two independent binomial populations the Fisher exact test and the chi-squared test with Yates's continuity correction are often suggested for small and intermediate size samples. The use of these tests is inappropriate in that they are extremely conservative. In this article we demonstrate that, even for small samples, the uncorrected chi-squared test (i.e., the Pearson chi-squared test) and the two-independent-sample t test are robust in that their actual significance levels are usually close to or smaller than the nominal levels. We encourage the use of these latter two tests.     

The emotional toll of postfeminist fatherhood

Postfeminism shapes the political economy of the workforce and household, constituting a re-entrenchment of traditional heterosexual gender regimes and the pressure to transgress them. Focusing on the understudied area of postfeminist masculinity, we analyze the emotional toll some fathers experience as a result of the fraught expectations to be the breadwinner, nurturing parent, and enlightened feminist spouse who completes equal domestic duties. Using empirical data of parents’ participation in a family-based health intervention, we argue that the paradoxical expectation to enact traditional gender relations and to adopt gender egalitarianism is exhausting, upsetting, and confusing for fathers. By focusing on the affective dimensions of postfeminism, we demonstrate how working to achieve the impossible expectation of doing “it all,” a bind that women have been caught in for centuries, takes an emotional toll on fathers and couples, leading to discontent at work and home, and in regard to their self-concept, parental role, and spousal relationship. We close by offering counter examples of fathers and couples who have disengaged from postfeminist parenting relations and have reached a state of contentment. Contrary to the alignment of postfeminism with positive affect, the experience of resisting postfeminist resulted in feelings of joy, pride, and satisfaction.     

Principles for Conduct of Pest Risk Analyses: Report of an Expert Workshop

The North American Free Trade Agreement (NAFTA) and the General Agreement on Tariffs and Trade (GATT) have focused attention on risk assessment of potential insect, weed, and animal pests and diseases of livestock. These risks have traditionally been addressed through quarantine protocols ranging from limits on the geographical areas from which a product may originate, postharvest disinfestation procedures like fumigation, and inspections at points of export and import, to outright bans. To ensure that plant and animal protection measures are not used as nontariff trade barriers, GATT and NAFTA require pest risk analysis (PRA) to support quarantine decisions. The increased emphasis on PRA has spurred multiple efforts at the national and international level to design frameworks for the conduct of these analyses. As approaches to pest risk analysis proliferate, and the importance of the analyses grows, concerns have arisen about the scientific and technical conduct of pest risk analysis. In January of 1997, the Harvard Center for Risk Analysis (HCRA) held an invitation-only workshop in Washington, D.C. to bring experts in risk analysis and pest characterization together to develop general principles for pest risk analysis. Workshop participants examined current frameworks for PRA, discussed strengths and weaknesses of the approaches, and formulated principles, based on years of experience with risk analysis in other setting and knowledge of the issues specific to analysis of pests. The principles developed highlight the both the similarities of pest risk analysis to other forms of risk analysis, and its unique attributes.     

The Nominal Group: A New Tool for Making Social Work Education Relevant

This article describes the nominal group technique and delineates the application of the approach to identifying specific course topics and emphases sought by students enrolling in undergraduate and graduate social work courses.     

Life Expectancy during the Great Depression in Eleven European Countries

The recent global economic recession has renewed interest in knowing whether a declining economy affects population health. Understanding the extreme case of the Great Depression may inform the current debate as well as theory regarding biological and behavioral adaptations to unwanted economic change. We test the hypothesis, recently suggested in the literature, that period life expectancy at birth improved during the Great Depression. We applied time‐series methods to annual period life expectancy data of the civilian population from eleven European countries. Methods control for trends and other forms of autocorrelation in life expectancy that could induce spurious associations. We cannot reject the null hypothesis that period life expectancy at birth during the Great Depression remained within the interval forecasted from historical values. Additional analyses using an automated, rule‐based methodology also cannot reject the null hypothesis. During the most severe phase of the Great Depression, period life expectancy in eleven European countries generally did not rise above expected levels.     

Births,debts and mirages: The impact of the Higher Education Contribution Scheme (HECS) and other factors on Australian fertility expectations

This paper uses survey data to examine the effect of the income-contingent charge mechanism, the Higher Education Contribution Scheme (HECS), and other demographic and attitudinal variables on fertility expectations in Australia over the recent past. HECS requires former Australian students to fund some of the costs of higher education through the repayment of interest-free loans made by the Australian government. Its defining characteristic is that repayments only occur when and if students future incomes exceed a particular level. Since its introduction in 1989, media and other populist commentary has suggested that HECS has had unanticipated effects on behaviour. Most recently, attention has focused on the effects of HECS on fertility, with some arguing that university graduates are delaying births, and having fewer children, because of their HECS debts. This paper demonstrates that the introduction of HECS has had no discernible impact on Australian fertility rates, nor on the number of children that people expect to have. However, education, age and a number of attitudinal factors are associated with significant differences in fertility expectations.     

Cross cultural comparisons of quality of life of Thais and Americans

Comparisons of quality of life (QOL) measures across cultures of countries in different stages of economic development have been very scarce. This study attempts to fill the void in the literature by investigating the level of overall life satisfaction and satisfaction with various domains of lives of Thais and Americans. Additionally, the relationships between satisfaction with domains of life and overall life satisfaction in each culture have been explored. The results of this study indicate that Thais are less satisfied with their lives in general and most of the domains of their lives than Americans. However, both Thais and Americans tend to be more satisfied with their personal domains of lives than environmental domains of lives. In addition, satisfaction with material possessions is found to contribute significantly to overall life satisfaction of Thais but not Americans. This suggests that material wealth or economic development is still a vital mechanism for enhancing QOL of people in Thailand, but is not important for enhancing QOL of people in the U.S.