Modified cross-validation in density estimation

We propose a new modified (biased) cross-validation method for adaptively determining the bandwidth in a nonparametric density estimation setup. It is shown that the method provides consistent minimizers. Some simulation results are reported on which compare the small sample behavior of the new and the classical cross-validation selectors.     

Recurrent pain in college students.

The authors investigated the prevalence of recurrent pain in a college student sample. Of the 1,564 students surveyed, 467 (29%) indicated that they had experienced recurrent pain at an intensity that was mostly in the mild-to-moderate range. Students who reported having recurrent pain were significantly older and more depressed than students who did not indicate they suffered from recurrent pain. Pain intensity was positively correlated (r = .14) with depression among the students who reported having recurrent pain. Implications of the findings for future research, treatment, and health promotion efforts are discussed.     

HIV-infected woman. Illness cognition assessment.

1. Special attention is particularly important in addressing the mental health needs of HIV-infected women. These needs may involve issues such as concerns about present or future pregnancy; child-rearing, often as single parents; poverty, illicit drug use or addiction; and the potential lack of support services. 2. Diagnosis of HIV infection in women may be overlooked, as the clinical signs that routinely trigger the suspicion of HIV illness in men are often interpreted to reflect depression or psychological factors, such as stress or overwork, rather than raise the suspicion of HIV infection in women. 3. Understanding a woman's illness cognition is an important component of designing strategies that can enhance coping. The picture a woman generates regarding her illness is a composite of her experiences and responses, and determines to a large extent what she will do in response to her illness.     

The effect of 1980s tort reform legislation on general liability and medical malpractice insurance

A large number of states adopted tort reforms in the mid-1980s to limit the dramatic surge in insurance losses and premiums. Evidence based on liability insurance data by state indicates that these reforms substantially influenced general liability insurance. The levels of losses, premiums, and loss ratios (a measure of insurance profitability) all reflected the impact of the reforms. The large-scale reform efforts in 1986 were particularly influential. Medical malpractice insurance was much less sensitive to the reform efforts.     

Procedures and tables for the construction and selection of chain sampling plans ChSP-4A(c1, c2,)r-Part 4

In this part of the series, the notion of average total inspection (ATI) is introduced to ChSP-4A(c1, c2)r plans, minimizing ATI at a given process average, while protection to the consumer is given in terms of average outgoing quality limit and limiting quality level. The procedure is similar to that of Dodge and Roming.     

A SCALE IN SEARCH OF A CONSTRUCT: COMMENTS ON GAVIN AND WAMBOLDT

The article examines some issues raised in Gavin and Wamboldt's (1992) recent study on the Family-of-Origin Scale (FOS) (Hovestadt, Anderson, Piercy, Cochran, & Fine, 1985). The discussion centers on unresolved concerns regarding the validity and utility of the FOS and on unsubstantiated and potentially misleading claims made in the Gavin and Wamboldt article. A case is made for conceptual and methodological precision in the study of family phenomena.     

A response to “the emotional consequences of physical child abuse” by Annaclare van Dalen

The author responds to the article by Annaclare van Dalen (1989), disputing her statement that there is little in the literature about the emotional consequences of child abuse. The author reviews the pertinent literature, which is abundant. The author disagrees with van Dalen's statement that the child experiences physical abuse outside the body, and with the statement that the child experiences sexual abuse as pleasurable. In addition the author disagrees with van Dalen's sharp differentiation between physical abuse and sexual abuse, and proposes that sexual abuse be regarded as a variant of physical abuse.     

What to Do at Low Doses: A Bounding Approach for Economic Analysis

To quantify the health benefits of environmental policies, economists generally require estimates of the reduced probability of illness or death. For policies that reduce exposure to carcinogenic substances, these estimates traditionally have been obtained through the linear extrapolation of experimental dose-response data to low-exposure scenarios as described in the U.S. Environmental Protection Agency's Guidelines for Carcinogen Risk Assessment (1986). In response to evolving scientific knowledge, EPA proposed revisions to the guidelines in 1996. Under the proposed revisions, dose-response relationships would not be estimated for carcinogens thought to exhibit nonlinear modes of action. Such a change in cancer-risk assessment methods and outputs will likely have serious consequences for how benefit-cost analyses of policies aimed at reducing cancer risks are conducted. Any tendency for reduced quantification of effects in environmental risk assessments, such as those contemplated in the revisions to EPA's cancer-risk assessment guidelines, impedes the ability of economic analysts to respond to increasing calls for benefit-cost analysis. This article examines the implications for benefit-cost analysis of carcinogenic exposures of the proposed changes to the 1986 Guidelines and proposes an approach for bounding dose-response relationships when no biologically based models are available. In spite of the more limited quantitative information provided in a carcinogen risk assessment under the proposed revisions to the guidelines, we argue that reasonable bounds on dose-response relationships can be estimated for low-level exposures to nonlinear carcinogens. This approach yields estimates of reduced illness for use in a benefit-cost analysis while incorporating evidence of nonlinearities in the dose-response relationship. As an illustration, the bounding approach is applied to the case of chloroform exposure.     

Benchmark Analysis: Shopping with Proper Confidence

We discuss the issue of using benchmark doses for quantifying (excess) risk associated with exposure to environmental hazards. The paradigm of low-dose risk estimation in dose-response modeling is used as the primary application scenario. Emphasis is placed on making simultaneous inferences on benchmark doses when data are in the form of proportions, although the concepts translate easily to other forms of outcome data.     

MEANINGFUL REGRESSION AND ASSOCIATION MODELS FOR CLUSTERED ORDINAL DATA

Many proposed methods for analyzing clustered ordinal data focus on the regression model and consider the association structure within a cluster as a nuisance. However, the association structure is often of equal interest—for example, temporal association in longitudinal studies and association between responses to similar questions in a survey. We discuss the use, appropriateness, and interpretability of various latent variable and Markov models for the association structure and propose a new structure that exploits the ordinality of the response. The models are illustrated with a study concerning opinions regarding government spending and an analysis of stability and change in teenage marijuana use over time, where we reveal different behavioral patterns for boys and girls through a comprehensive investigation of individual response profiles.