The urban neighborhood and cognitive functioning in late middle age

This study examines the association of cognitive functioning with urban neighborhood socioeconomic disadvantage and racial/ethnic segregation for a U.S. national sample of persons in late middle age, a time in the life course when cognitive deficits begin to emerge. The key hypothesis is that effects of neighborhood on cognitive functioning are not uniform but are most pronounced among subgroups of the population defined by socioeconomic status and race/ethnicity. Data are from the third wave of the Health and Retirement Survey for the birth cohort of 1931 to 1941, which was 55 to 65 years of age in 1996 (analytic N = 4,525), and the 1990 U.S. Census. Neighborhood socioeconomic disadvantage has an especially large negative impact on cognitive functioning among persons who are themselves poor, an instance of compound disadvantage. These findings have policy implications supporting "upstream" interventions to enhance cognitive functioning, especially among those most adversely affected by neighborhood socioeconomic disadvantage.     

Worker Satisfaction Following Employment Restructuring: Effects of Nonstandard Workers and Downsizing on Job Satisfaction in Taiwan

Since the 1980s, many employment relationships in Taiwan have evolved from regular and long-term to contingent and short-term, with widespread downsizing adding a considerable amount of instability. Since these changes are part of a global trend, there is a growing literature concerning their influences on worker attitudes and work life quality. Here we analyze the impacts of changing employment practices on the quality of work life among Taiwanese workers, specifically analyzing the effects of nonstandard work arrangements and downsizing on job satisfaction. Data are from the 2005 Taiwan Social Change Survey, First Wave of the Fifth Phase: Work and Life Module. Our two main findings are (a) degree of use of nonstandard workers exerts a range of negative impacts on job satisfaction among regular workers, and (b) degree of downsizing exerts similar negative effects. We also discuss the moderating impacts of using nonstandard workers as part of a downsizing strategy.     

Using Frailty Models to Identify the Longitudinal Biomarkers in Survival Analysis

We introduce a score test to identify longitudinal biomarkers or surrogates for a time to event outcome. This method is an extension of Henderson et al. (2000 Henderson , R. , Diggle , P. , Dobson , A. ( 2000 ). Joint modelling of longitudinal measurements and event time data . Biostatistics 1 ( 4 ): 465 – 480 .[Crossref], [PubMed] , [Google Scholar], 2002 Henderson , R. , Diggle , P. , Dobson , A. ( 2002 ). Identification and efficacy of longitudinal markers for survival . Biostatistics 3 ( 1 ): 33 – 50 .[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). In this article, a score test is based on a joint likelihood function which combines the likelihood functions of the longitudinal biomarkers and the survival times. Henderson et al. (2000 Henderson , R. , Diggle , P. , Dobson , A. ( 2000 ). Joint modelling of longitudinal measurements and event time data . Biostatistics 1 ( 4 ): 465 – 480 .[Crossref], [PubMed] , [Google Scholar], 2002 Henderson , R. , Diggle , P. , Dobson , A. ( 2002 ). Identification and efficacy of longitudinal markers for survival . Biostatistics 3 ( 1 ): 33 – 50 .[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) assumed that the same random effect exists in the longitudinal component and in the Cox model and then they can derive a score test to determine if a longitudinal biomarker is associated with time to an event. We extend this work and our score test is based on a joint likelihood function which allows other random effects to be present in the survival function.

Considering heterogeneous baseline hazards in individuals, we use simulations to explore how the factors can influence the power of a score test to detect the association of a longitudinal biomarker and the survival time. These factors include the functional form of the random effects from the longitudinal biomarkers, in the different number of individuals, and time points per individual. We illustrate our method using a prothrombin index as a predictor of survival in liver cirrhosis patients.     

A Design For Survival Studies: A Multi-regional Trial With Unrecognized Heterogeneity

A bridging study defined by ICH E5 is usually conducted in the new region after the test product has been approved for commercial marketing in the original region due to its proven efficacy and safety. However, extensive duplication of clinical evaluation in the new region not only requires valuable development resources but also delay availability of the test product to the needed patients in the new regions. To shorten the drug lag or the time lag for approval, simultaneous drug development, submission, and approval in the world may be desirable. Recently, multi-regional trials have attracted much attention from sponsors as well as regulatory authorities. Current methods for sample determination are based on the assumption that true treatment effect is uniform across regions. However, unrecognized heterogeneity among patients as ethnic or genetic factor will effect patients’ survival. Using the simple log-rank test for analysis of treatment effect on survival in studies under heterogeneity may be severely underpowered. In this article, we address the issue that the treatment effects are different among regions to design a multi-regional trial. The optimal log-rank test is employed to deal with the heterogeneous effect size among regions. The test statistic for the overall treatment effect is used to determine the total sample size for a multi-regional trial and the consistent trend and the proposed criteria are used to rationalize partition sample size to each region.     

Sample Size Determination and Rational Partition for A Multi- Regional Trial for Survival (Time-To-Event) Data with Unrecognized Heterogeneity that Interacts with Treatment

To shorten the drug lag or the time lag for approval, simultaneous drug development, submission, and approval in the world may be desirable. Recently, multi-regional trials have attracted much attention from sponsors as well as regulatory authorities. Current methods for sample determination are based on the assumption that true treatment effect is uniform across regions. However, unrecognized heterogeneity among patients as ethnic or genetic factor will effect patients’ survival. In this article, we address the issue that the treatment effects with unrecognized heterogeneity that interacts with treatment are among regions to design a multi-regional trial. The log-rank test is employed to deal with the heterogeneous effect size among regions. The test statistic for the overall treatment effect is used to determine the total sample size for a multi-regional trial and the consistent trend is used to rationalize partition for sample size to each region.     

Sample size determination for quality control process using a multiple components tolerance interval

ABSTRACT

In the past, a tolerance interval was used for the statistical quality control process on raw materials and/or the final product. In the traditional concept of the tolerance interval, the variance from the measurements is a single component. However, we can find examples about several components that could vary in their measurements, so an approximate method must be found to modify the traditional tolerance interval. Now we employ a tolerance interval considering multiple components in the variance from the measurements to deal with quality control process. In our paper, the proposed method is used to solve the sample size determination for a two-sided tolerance interval approach considering multiple components on the variance of measurements.     

Comparisons of allocating sample size rationally into individual regions under heterogeneous effect size in a multiregional trial by a fixed effect model and a random effect model

ABSTRACT

Recently, sponsors and regulatory authorities pay much attention on the multiregional trial because it can shorten the drug lag or the time lag for approval, simultaneous drug development, submission, and approval in the world. However, many studies have shown that genetic determinants may mediate variability among persons in response to a drug. Thus, some therapeutics benefit part of treated patients. It means that the assumption of homogeneous effect size is not suitable for multiregional trials. In this paper, we conduct the sample size determination of a multiregional clinical trial calculated by fixed effect and random effect under the assumption of heterogeneous effect size. The performances of fixed effect and random effect on allocating sample size on a specific region are compared by statistical criteria for consistency between the region of interest and overall results.     

Assessing the Impact of Social Factors on the Mental Health of Chinese at Risk Adolescents in Hong Kong

Correspondence to Dr Cindy Davis, University of Tennessee, College of Social Work, Nashville Campus, 193E Polk Avenue, Nashville, TN., 37210, USA. E-mail: cdavis3eutk.edu Summary The purpose of this study was to explore the relationship offamily, peer and school factors on the mental health of Chinesemale and female at risk adolescents and secondary school studentsin Hong Kong. Questionnaire surveys based on various standardizedassessment scales were conducted with 398 (183 female and 215male) Chinese at risk adolescents and 320 (160 female and 160male) Chinese secondary school students between 12 and 18 yearsof age in Hong Kong. Compared to secondary school students,at risk adolescents had poorer relations with parents, morenegative family and peer influence, a more negative school environment,and poorer social functioning. Findings also revealed that femaleparticipants had more somatic symptoms, anxiety, and depressioncompared to males. The importance of environmental factors onthe mental health of Chinese adolescents supports previous researchin Western countries. Implications for intervention and preventionwere discussed from a cross-cultural perspective.     

Correlates of wife assault in Hong Kong Chinese families

The objective of this study was the risk factors of wife assault in Hong Kong Chinese families. The sample included 107 battered women from a refuge for battered women. Factor analysis revealed risk factors like dominance, stress, poor anger management, aggressive personality, conflict, lack of empathy, masculine gender role stress, sense of insecurity, relationship distress, and violent socialization. Correlation analysis indicated that dominance, spousal conflict, and sense of insecurity increase the likelihood of carrying out minor physical assault and using psychological aggression, while aggressive personality predicts severe physical assault and injury. The risk factors were explained in terms of traditional Chinese concepts of gender role expectations of men and women and face orientations. The present study provides some evidence relating to the risk factors of wife assault in Chinese families.