Building adaptive estimating equations when inverse of covariance estimation is difficult

Summary. To construct an optimal estimating function by weighting a set of score functions, we must either know or estimate consistently the covariance matrix for the individual scores. In problems with high dimensional correlated data the estimated covariance matrix could be unreliable. The smallest eigenvalues of the covariance matrix will be the most important for weighting the estimating equations, but in high dimensions these will be poorly determined. Generalized estimating equations introduced the idea of a working correlation to minimize such problems. However, it can be difficult to specify the working correlation model correctly. We develop an adaptive estimating equation method which requires no working correlation assumptions. This methodology relies on finding a reliable approximation to the inverse of the variance matrix in the quasi-likelihood equations. We apply a multivariate generalization of the conjugate gradient method to find estimating equations that preserve the information well at fixed low dimensions. This approach is particularly useful when the estimator of the covariance matrix is singular or close to singular, or impossible to invert owing to its large size.     

Residential Mobility Across Local Areas in the United States and the Geographic Distribution of the Healthy Population

Determining whether population dynamics provide competing explanations to place effects for observed geographic patterns of population health is critical for understanding health inequality. We focus on the working-age population—the period of adulthood when health disparities are greatest—and analyze detailed data on residential mobility collected for the first time in the 2000 U.S. census. Residential mobility over a five-year period is frequent and selective, with some variation by race and gender. Even so, we found little evidence that mobility biases cross-sectional snapshots of local population health. Areas undergoing large or rapid population growth or decline may be exceptions. Overall, place of residence is an important health indicator; yet, the frequency of residential mobility raises questions of interpretation from etiological or policy perspectives, complicating simple understandings that residential exposures alone explain the association between place and health. Psychosocial stressors related to contingencies of social identity associated with being black, urban, or poor in the United States may also have adverse health impacts that track with structural location even with movement across residential areas.     

Work-related violence as a predictor of fatigue: A 5-year follow-up of the Danish Work Environment Cohort Study

The purpose of this study was to examine whether time management behaviours moderated relations between stressors (role conflict, role overload, work-family conflict, and family-work conflict) and strain, as measured by scores on the General Health Questionnaire. It was predicted that use of time management behaviours would be negatively associated with strain. These relations, however, were expected to be mediated by feelings of control over time. It was further predicted that the use of time management behaviours would attenuate stressor-strain relations. Data collected from 525 employed men and women indicated, as predicted, that use of time management behaviours was negatively associated with strain. These relations were partially mediated by feelings of control over time. Moderator tests failed to provide support for time management behaviour as a moderator of stressor-strain relations. Implications of findings are discussed and future directions for time management research are suggested.     

Initiating a Caregiving Relationship: Pregnancy and Childbirth Factors as Predictors of Maternal Sensitivity

The aim of this study was to investigate the relations between pregnancy and childbirth factors and subsequent quality of maternal interactive behavior in a sample of 116 full‐term infants and their mothers. Mothers reported on the conditions of childbirth when infants were 6–8 months of age, and their interactive behavior was observed during a home visit at 12 months. Results showed that mothers who did not report health problems during pregnancy and who had longer pregnancies, shorter hospital stays, natural deliveries, and infants with greater birthweight were found to be more sensitive during interactions with infants at 12 months. All these relations held after accounting for socio‐economic factors and maternal psychological distress, except for the effect of type of delivery. This pattern of results, however, was almost exclusively due to mothers who already had at least one other child. Very few such relations were found among primiparous mothers.     

Stability of Maternal Autonomy Support between Infancy and Preschool Age

The goals of this article were to examine (1) the relative and absolute stability of maternal autonomy support between infancy and preschool age, and (2) the moderating role of child gender, maternal attachment state of mind, and stressful life events. Sixty‐nine mother–child dyads participated in five visits when the child was 8, 15, and 18 months, as well as 2 and 3 years. The results suggested that maternal autonomy support is stable in relative terms, but that its mean level decreases over time. Moreover, there was significant relative stability only for mothers of girls, mothers who showed greater coherence of mind with respect to attachment, and mothers who experienced fewer stressful life events. These results speak to the relevance of investigating parent, child, and contextual factors when examining the conditions that promote or hinder stability in parenting behaviors.     

Decoding the Miss Daisy Syndrome: An Examination of Subjective Responses to Mobility Change

The subjective responses associated with personal life space and mobility status were explored. Thirty individuals participated in focus groups based on self-rated disability status, current places visited, and availability. Qualitative analyses revealed that most participants equated personal mobility with driving a vehicle. Attitudes concerning mobility status and preparedness for change varied based on disability level and personal experience. Fear of dependence from future mobility loss was prominent in all groups. Few participants acknowledged significant planning for future retirement from driving or other mobility challenges. An understanding of common attitudes, perceptions and meanings can inform professionals who intervene and support older adults experiencing mobility changes.     

Virtue Ethics for Social Work: A New Pedagogy for Practical Reasoning

Virtue ethics has begun to regain popularity among philosophers, and recent commentators have expressed enthusiasm vis-à-vis its appropriateness and strengths in the task of practising ethically in social work. Notwithstanding this growing interest in adopting virtue ethics frameworks, some difficulties arise when the question of how to develop social work virtues is posed. By examining the concept of reflective practice, and building from the work of Alasdair MacIntyre, this article explores how practical reasoning as a collective activity can help social work students in their moral development by developing and nurturing appropriate virtues for social work. A combination of Socratic dialogue activities, lectures and seminar work is highlighted as a potential pedagogical approach to teaching ethics and values on an undergraduate social work module at Coventry University. The approach is then appraised in the light of a set of module evaluation questionnaires distributed to students who undertook the module during the academic year 2006–2007.