Assessing accuracy of a continuous screening test in the presence of verification bias

Summary.  In studies to assess the accuracy of a screening test, often definitive disease assessment is too invasive or expensive to be ascertained on all the study subjects. Although it may be more ethical or cost effective to ascertain the true disease status with a higher rate in study subjects where the screening test or additional information is suggestive of disease, estimates of accuracy can be biased in a study with such a design. This bias is known as verification bias. Verification bias correction methods that accommodate screening tests with binary or ordinal responses have been developed; however, no verification bias correction methods exist for tests with continuous results. We propose and compare imputation and reweighting bias-corrected estimators of true and false positive rates, receiver operating characteristic curves and area under the receiver operating characteristic curve for continuous tests. Distribution theory and simulation studies are used to compare the proposed estimators with respect to bias, relative efficiency and robustness to model misspecification. The bias correction estimators proposed are applied to data from a study of screening tests for neonatal hearing loss.     

Residual analysis for spatial point processes (with discussion)

Summary.  We define residuals for point process models fitted to spatial point pattern data, and we propose diagnostic plots based on them. The residuals apply to any point process model that has a conditional intensity; the model may exhibit spatial heterogeneity, interpoint interaction and dependence on spatial covariates. Some existing ad hoc methods for model checking (quadrat counts, scan statistic, kernel smoothed intensity and Berman's diagnostic) are recovered as special cases. Diagnostic tools are developed systematically, by using an analogy between our spatial residuals and the usual residuals for (non-spatial) generalized linear models. The conditional intensity λ plays the role of the mean response. This makes it possible to adapt existing knowledge about model validation for generalized linear models to the spatial point process context, giving recommendations for diagnostic plots. A plot of smoothed residuals against spatial location, or against a spatial covariate, is effective in diagnosing spatial trend or co-variate effects. Q – Q -plots of the residuals are effective in diagnosing interpoint interaction.     

Testing How Management Matters in an Era of Government by Performance Management

Public administration finds itself in an era of government byperformance management, which is reflected in the widespreadassumption that management is a key determinant of performance,and that it is reasonable to expect managers to measurably improveorganizational effectiveness. This article joins a growing literaturein seeking to conceptualize and empirically test how externalenvironmental influences and internal management factors combineto create performance, relying on data from the 2002–2003National Administrative Studies Project (NASP-II) survey ofstate government health and human services officials. We categorizemanagerial efforts to facilitate organizational performanceas determined either through their interactions with the organizationalenvironment, or through employing workable levers to changeinternal organizational culture, structure, and technology.Among the external environmental variables we find that thesupport of elected officials and the influence of the publicand media have a positive impact on effectiveness. Among internalmanagement choices, the ability to create a developmental organizationalculture, establish a focus on results through goal clarity,and decentralize decision-making authority are all positivelyassociated with organizational effectiveness.     

The organizational formation of atmospheric science

In this paper, the history of atmospheric science is traced, from the earliest discussions from meteorologists, and the first meetings to describe this new research area. The development of atmospheric science proceeded in three phases with each phase being marked by the attempt to organize resources, and bring into the atmospheric science network, scientists from other fields. I argue here that this construction of a science provides evidence of the social nature of science as well as the importance of organizations to the creation of a science.     

Measuring the non-profit sector cross-nationally: a comparative methodology

As a result in part of the way non-profit institutions are defined and treated in the United Nations System of National Accounts (SNA), little is known about the size, scope, financial base and role of this set of institutions at the international level, even though their importance is increasingly being recognised throughout the world. To remedy this significant lack of systematic information on non-profit institutions cross-nationally, the Johns Hopkins Comparative Nonprofit Sector Project has undertaken a major analysis of the economic role of this sector in twelve countries throughout the world, utilising a more meaningful definition of the sector and an approach that is otherwise consistent with the overall thrust of the SNA system. This paper outlines the basis of the more inclusive definition of the non-profit sector embodied in this project, the classification system formulated to structure data-gathering on this more broadly-defined sector and the data assembly strategy developed to build up key estimates of the scale, structure and revenue sources of the non-profit sector in the project countries. The article concludes with a recommendation to incorporate a similar approach to the assembly of data on the non-profit sector into the ongoing SNA system on a regular basis.Professor Lester Salamon is Director of the Institute for Policy Studies and Director of the Comparative Nonprofit Sector Project at the Johns Hopkins University, Baltimore, Maryland, 21218.Helmut Anheier is Research Scientist at the Institute for Policy Studies at the Johns Hopkins University and Assistant Professor of Sociology at Rutgers University, New Brunswick, New Jersey, 08903. He is co-editor ofVoluntas.     

Gender and returns to promotion: The role of social and power relations

This study extends a theoretical framework of structural resources and vulnerabilities to an examination of individual promotion outcomes. Promotions of 454 individuals to administrative and professional staff positions in one higher education organization are analyzed. The findings confirm that both individual and structural resources are important for explaining the administrative level achieved by promotion in this setting. Although the returns to resouces do not vary by gender, women receive significantly less return to their promotions than men do to theirs. These findings underscore the importance of examining not only individual and structural resources but also the role of gender in the social and power relations that influence the promotion of women and men in organizations.     

哈萨克斯坦共和国的现代教育体制

哈萨克斯坦共和国的现代教育体制是国家经济的重要组成部分 ,是国家内外安全的保证。国家安全的方方面面 :经济和军事、生态和技术、文化和管理——都对教育体系有影响。教育体制质量上的转变对国家的主权、政治及经济上真正的独立都发挥着重要的作用。本文分析了哈萨克教育体制中基本因素的动态变化情况     

Stress at work and psychological and immunological parameters in a group of Norwegian female bank employees

This study concerned the immunological correlates of stress and work. Self reported stress, emotional state, ego-strength, and defensiveness were examined in relation to measures of cellular immunity (T-cell response to Con A and number of T4 and T8 cells) and humoral immunity (concentrations of immunoglobulins and complement components in plasma) in a group of 96 Norwegian female bank employees. The analyses showed that workload, the stress factor with the highest group mean, was associated with number of T-cells, while strain due to body posture during work was related to concentrations of IgM and C3. Further, depression was significantly correlated with IgM concentration and T-cell number, and anxiety with C3 concentration. T-cell activity was the immunological parameter most consistently associated with psychological well-being, showing positive correlations with defensiveness and ego-strength and negative correlations with anxiety and depression. In conclusion, T-cell number and concentrations of IgM and C3 were sensitive to both work-related stress experience and emotional distress. Coping abilities, indicated by the MMPI Ego-strength scale and emotional distress, were reflected in T-cell activity; insufficient coping was associated with low T-cell activity.