Parametric and nonparametric methods for confidence intervals and sample size planning for win probability in parallel-group randomized trials with Likert item and Likert scale data

Data on the Likert scale are ubiquitous in medical research, including randomized trials. Statistical analysis of such data may be conducted using the means of raw scores or the rank information of the scores. In the context of parallel-group randomized trials, we quantify treatment effects by the probability that a subject in the treatment group has a better score than (or a win over) a subject in the control group. Asymptotic parametric and nonparametric confidence intervals for this win probability and associated sample size formulas are derived for studies with only follow-up scores, and those with both baseline and follow-up measurements. We assessed the performance of both the parametric and nonparametric approaches using simulation studies based on real studies with Likert item and Likert scale data. The simulation results demonstrate that even without baseline adjustment, the parametric methods did not perform well, in terms of bias, interval coverage percentage, balance of tail error, and assurance of achieving a pre-specified precision. In contrast, the nonparametric approach performed very well for both the unadjusted and adjusted win probability. We illustrate the methods with two examples: one using Likert item data and the other using Like scale data. We conclude that non-parametric methods are preferable for two-group randomization trials with Likert data. Illustrative SAS code for the nonparametric approach using existing procedures is provided.     

Linking Changes in Parenting to Parent–Child Relationship Quality and Youth Self‐Control: The Strong African American Families Program

A randomized prevention trial was conducted contrasting families who took part in the Strong African American Families Program (SAAF), a preventive intervention for rural African American mothers and their 11‐year‐olds, with control families. SAAF is based on a conceptual model positing that changes in intervention‐targeted parenting behaviors would enhance responsive‐supportive parent–child relationships and youths' self‐control, which protect rural African American youths from substance use and early sexual activity. Parenting variables included involvement‐vigilance, racial socialization, communication about sex, and clear expectations for alcohol use. Structural equation modeling analyses indicated that intervention‐induced changes in parenting were linked with changes in responsive–supportive parent–child relationships and youth self‐control.     

An epidemic of contact dermatitis at the University of Hawaii Manoa

Seventy-five cases of contact dermatitis at the University of Hawaii Manoa campus were traced to trees planted near a residence hall. A number of university and public health offices were involved in finding the cause of the "mystery rash."     

The effect of vertex and edge deletion on the edge metric dimension of graphs

Journal of Combinatorial Optimization - Let $$G=(V(G),E(G))$$ be a connected graph. A set of vertices $$S\subseteq V(G)$$ is an edge metric generator of G if any pair of edges in G can be...     

“No Thanks,We’re Full”: Individual Characteristics,National Context,and Changing Attitudes Toward Immigration1

In this paper we examine how individual‐level characteristics and national context affect attitudes toward immigration. Although many previous studies have compared attitudes toward immigration across countries, little attention has been paid to how attitudes may be affected by changes within a country over time. We take advantage of seventeen national Canadian Gallup surveys to consider how differences in national economic conditions and changing immigration flows affect attitudes and changes in attitudes between 1975 and 2000. While the state of the national economy affects attitudes this is not the case for the rate of immigration. Rather than affecting some groups more than others the state of the economy has a relatively uniform effect across groups. Our results also show that far from being a continuum, being anti‐immigration and being pro‐immigration are qualitatively different. Interest, ideology, and the national economy affect anti‐immigration sentiments, but only ideology affects pro‐immigration sentiments.     

Perceived social support,perception of competence,and hope among Chinese children with attention deficit hyperactivity disorder in a Chinese context: Children's perspective

This paper reports on the results of a study (n = 113 children with attention deficit hyperactivity disorder) that examined the effects of the children's perception of the social support (PSS) they receive from their mothers, fathers, teachers, and friends on their sense of competence and hope. PSS explained 13% of the children's overall sense of competence and 4% of their sense of hope. In the perspective of children with attention deficit hyperactivity disorder, the amount of maternal support, both in terms of importance and availability, was higher than that of their paternal support. However, the results of a multiple regression analysis have shown that paternal support accounted for 3% of the variance in the children's overall sense of competence and 5% in the variance of their physical competence. PSS from teachers had significantly explained 5%, 4%, and 4% of the variance in the children's overall, social, and physical competence, respectively. The PSS from friends significantly explained 7% of the variance in the children's cognitive competence and 4% of the variance in hope. Theoretical and clinical implications of the study are discussed.     

Maximum likelihood estimation foe two parameter exponentials under type I censoring

The paper considers maximum likelihood estimation of the location parameters and the failure rates of two parameter exponentials under type I censoring. Both the one and two sample cases are considered. It turns out that by debiasing the maximum likelihood estimators of the location parameters, one can achieve asymptotically 50% mean squared error reduction.     

A practitioner's reflections on facilitating organization development in South African organizations

Globalization, contrary to the opinion of many HRD professionals, has led to a better world, one in which greater numbers of people have the opportunity for peace, prosperity and freedom. Anti-global critics are tragically wrong for they condemn millions of people to poverty, disease, force migrations, ethical strife, and terrorism. HRD professionals shold not be persuaded by anecdotal, selective and sentimental stories, but act with real facts and offer real, long-term solutions.     

Accounting for Men’s Refusal of Heterosex: A Story-Completion Study With Young Adults

In the present study we bring together theory regarding the construction of heterosexuality and masculinities to understand the shifting and changing terrain of heterosexual sex (heterosex). We use inductive qualitative content analysis of story completion data to discover the different ways that heterosex is constructed by the male and female respondents in scenarios where women initiate sex and men, at first, refuse. The stories represented a spectrum of responses that reify and subvert dominant understandings of heterosex. Five major themes were generated from the current data (1) men should initiate sex, (2) he wants to take it slowly, (3) it is natural for men to want sex, (4) it is men’s job to look after women, and (5) coercion. We discuss in detail the dominant narratives described by women and men and how they may be shifting. The study thus provides a rich, experience-based representation of heterosexual sexual activity and suggests subtle shifts in how masculinity is managed within heterosexual relationships.