Evaluating health outcomes of criminal justice populations using record linkage: the importance of aliases

Individuals in contact with the criminal justice system are a key population of concern to public health. Record linkage studies can be useful for studying health outcomes for this group, but the use of aliases complicates the process of linking records across databases. This study was undertaken to determine the impact of aliases on sensitivity and specificity of record linkage and how this affects ascertainment of mortality. Records for a cohort of prisoners were linked to methadone maintenance treatment (MMT) and mortality records. The record linkage was conducted in two stages. First, the linkage was undertaken using the participant's name and date of birth as recorded in a prior study. Then, a second linkage was undertaken using these identifiers, plus all known aliases. Sensitivity was 64%, and specificity 100%, for the first linkage. When aliases were added to the linkage, sensitivity increased to 86% and specificity remained 100%. The standardized mortality ratio was 4.3 for the first linkage, increasing to 6.1 when aliases were used. These results suggest that the potential effects of participant aliases on linkage outcomes, and methods for mitigating these effects should be carefully considered when planning and undertaking record linkage studies with criminal justice populations.     

Preliminary Goodness-of-Fit Tests for Normality do not Validate the One-Sample Student t

One of the most basic topics in many introductory statistical methods texts is inference for a population mean, μ. The primary tool for confidence intervals and tests is the Student t sampling distribution. Although the derivation requires independent identically distributed normal random variables with constant variance, σ², most authors reassure the readers about some robustness to the normality and constant variance assumptions. Some point out that if one is concerned about assumptions, one may statistically test these prior to reliance on the Student t. Most software packages provide optional test results for both (a) the Gaussian assumption and (b) homogeneity of variance. Many textbooks advise only informal graphical assessments, such as certain scatterplots for independence, others for constant variance, and normal quantile–quantile plots for the adequacy of the Gaussian model. We concur with this recommendation. As convincing evidence against formal tests of (a), such as the Shapiro–Wilk, we offer a simulation study of the tails of the resulting conditional sampling distributions of the Studentized mean. We analyze the results of systematically screening all samples from normal, uniform, exponential, and Cauchy populations. This pretest does not correct the erroneous significance levels and makes matters worse for the exponential. In practice, we conclude that graphical diagnostics are better than a formal pretest. Furthermore, rank or permutation methods are recommended for exact validity in the symmetric case.     

Marginal Correlation in Longitudinal Binary Data Based on Generalized Linear Mixed Models

This work aims at investigating marginal correlation within and between longitudinal data sequences. Useful and intuitive approximate expressions are derived based on generalized linear mixed models. Data from four double-blind randomized clinical trials are used to estimate the intra-class coefficient of reliability for a binary response. Additionally, the correlation between such a binary response and a continuous response is derived to evaluate the criterion validity of the binary response variable and the established continuous response variable.     

Scale-space theory: a basic tool for analyzing structures at different scales

An inherent property of objects in the world is that they only exist as meaningful entities over certain ranges of scale. If one aims to describe the structure of unknown real-world signals, then a multi-scale representation of data is of crucial importance. This paper gives a tutorial review of a special type of multi-scale representation—linear scale-space representation—which has been developed by the computer vision community to handle image structures at different scales in a consistent manner. The basic idea is to embed the original signal into a one-parameter family of gradually smoothed signals in which the fine-scale details are successively suppressed. Under rather general conditions on the type of computations that are to be performed at the first stages of visual processing, in what can be termed 'the visual front-end', it can be shown that the Gaussian kernel and its derivatives are singled out as the only possible smoothing kernels. The conditions that specify the Gaussian kernel are, basically, linearity and shift invariance, combined with different ways of formalizing the notion that structures at coarse scales should correspond to simplifications of corresponding structures at fine scales-they should not be accidental phenomena created by the smoothing method. Notably, several different ways of choosing scale-space axioms give rise to the same conclusion. The output from the scale-space representation can be used for a variety of early visual tasks; operations such as feature detection, feature classification and shape computation can be expressed directly in terms of (possibly non-linear) combinations of Gaussian derivatives at multiple scales. In this sense the scale-space representation canserve as a basis for early vision. During the last few decades, a number of other approaches to multiscale representations have been developed, which are more or less related to scale-space theory, notably the theories of pyramids, wavelets and multi grid methods.Despite their qualitative differences, the increasing propularity of each of these approaches indicates that the crucial notion of scale is increasingly appreciated by the computer.vision community and by researchers in other related fields. An interesting similarity to biological vision is that the scale-space operators closely resemble receptive field profiles registered in neurophysiological studies of the mam- malian retina and visual cortex.     

A NOTE ON MODELING PROJECT INTERDEPENDENCE IN RESEARCH AND DEVELOPMENT*

This note is concerned with the problem of resource allocation under uncertainty in a research and development laboratory. A distinction is defined between project interrelationships that are specific (or internal) to certain projects and interrelationships resulting from external environmental factors. Formulations are introduced that allow both types of interrelationships to be formally included in a resource allocation optimization model. In the case of external environmental factors, an example is presented and analyzed.     

Social positioning theory and quantum mechanics

Social positioning theory, or an account of the human individual that it grounds, qualifies as a quantum social theory. This is an assessment that I explain and defend in the paper. It is of interest in that, in a world where increasing numbers are seeking to construct quantum social theories, it serves to help demonstrate that this goal can be achieved without giving up on meeting criteria like explanatory intelligibility or power or discarding real-world notions like human (and other) entities. As it turns out, a central feature of the account defended and a core element of the ‘standard’ interpretation of quantum mechanics are found to stand in an interesting, unanticipated and suggestive relation to each other.     

Changes in Racial Apathy Among White Young Adults: A Five-Year National Panel Study

This study investigates changes in racial apathy among white young adults using nationally representative panel survey data from the NSYR. Our regression models include social background, social values, and academic orientation variables specified as important correlates of racial apathy in prior cross-sectional studies. We also include interracial contact variables, which existing studies neglect. According to intergroup contact theory, interracial contact should predict decreases in racial apathy. We find variables specified as important correlates in prior cross-sectional studies do not explain changes in racial apathy across time. Surprisingly, interracial friendship associates negatively with increases and decreases in racial apathy. Further, interracial dating predicts increases in racial apathy across time. These findings suggest racial apathy may be dissimilar to other forms of white racial prejudice and interracial contact may be an ineffective method to reduce contemporary forms of white racial prejudice.     

Employment of Older People in the European Union

Abstract. This article identifies the alternative employment modes of older workers in the European Union. Against a background of changing levels of labour force participation and declining employment opportunities the paper describes and discusses the relative significance for older workers of alternative employment modes. Two atypical modes, part‐time and self‐employment, are discussed in detail. The paper concludes that atypical employment modes offer ageing employees the opportunity to gradually retire by providing a bridge between full‐time employment and final retirement.