Approaches to sample size calculation for clinical trials in rare diseases

We discuss 3 alternative approaches to sample size calculation: traditional sample size calculation based on power to show a statistically significant effect, sample size calculation based on assurance, and sample size based on a decision‐theoretic approach. These approaches are compared head‐to‐head for clinical trial situations in rare diseases. Specifically, we consider 3 case studies of rare diseases (Lyell disease, adult‐onset Still disease, and cystic fibrosis) with the aim to plan the sample size for an upcoming clinical trial. We outline in detail the reasonable choice of parameters for these approaches for each of the 3 case studies and calculate sample sizes. We stress that the influence of the input parameters needs to be investigated in all approaches and recommend investigating different sample size approaches before deciding finally on the trial size. Highly influencing for the sample size are choice of treatment effect parameter in all approaches and the parameter for the additional cost of the new treatment in the decision‐theoretic approach. These should therefore be discussed extensively.     

Forthcoming in Sociological Forum

Table of Contents

Forthcoming in Sociological Forum     

Correlates of women's sexual assault disclosure to informal and formal support sources

Deciding which people to tell about sexual assault is an important and potentially consequential decision for sexual assault survivors. Women typically receive many different positive and negative reactions when they disclose sexual assault to social support sources. A diverse sample of adult sexual assault survivors in the Chicago area was surveyed about sexual assault experiences, social reactions received when disclosing assault to others, attributions of blame, coping strategies, and PTSD. Analyses were run to identify demographic, assault, and postassault factors differentiating women disclosing to informal support sources only from those disclosing to both informal and formal support sources. Women disclosing to both formal and informal support sources experienced more stereotypical assaults, had more PTSD symptoms, engaged in less behavioral self-blame, and received more negative social reactions than those disclosing to informal support sources only. Implications for future research and intervention are discussed.     

The Incidence and Impact of Policy-Oriented Collective Action: Competing Views

This article asks four questions: (1) What are our theoretical expectations about the incidence of policy-oriented collective action and its impact? (2) What do the data show about the incidence of collective action and its impact? (3) How might the impact of collective action be related to its incidence? (4) What do our findings imply for our understanding of democratic politics? We suggest that predictions that little collective action will occur are more accurate than conventionally believed; that such action is often ineffective; that it may be ineffective partly because it is so infrequent; and that the analysis of the determinants of policy change should be rethought as a result.     

Interdependencies, values and the reshaping of difference: gender and generation at the birth of twentieth-century modernity

The paper explores the mutuality of values, claims and social relations in the process of social change. Values are not separable from social relations but are embedded in the shaping and reshaping of social difference and interdependence. The paper focuses on developments around the turn of the twentieth century, and analyses changes in the relative social positioning of children and adults, and women and men, shifting patterns of interdependence, and linked values and ideas about difference. The reconfiguring of generational and gender relations was integral to the first fertility decline, to transformation in family life and societal divisions of labour, and to the embedding of particular values and claims regarding gendered difference, identities and gender appropriate roles. Analysis of these developments reveals the mutuality of 'cultural' and 'material' processes and holds lessons for interpreting social change today.     

Social reactions to child sexual abuse disclosures: a critical review

Recent studies have examined disclosure of child sexual abuse to determine the correlates and consequences of telling others about this form of victimization. The present article reviews the current empirical literature on disclosure and reactions to adult survivors to assess what is known about the process of disclosure and whether telling others is therapeutic and leads to positive outcomes. Most studies assessing social reactions in detail have concerned adult survivors retrospectively reporting on their disclosures of child sexual abuse. Few empirical studies have been conducted in this area but research suggests that few victims tell anyone about child sexual abuse as children, and that the type of reactions to disclosure vary according to when disclosure occurs (childhood or adulthood), the extent and nature of the disclosure, and the person to whom one discloses. Clear evidence shows that negative social reactions are harmful to survivors' well-being, but better assessment of specific reactions and their effects are needed in theoretically-based studies to evaluate how these responses affect survivors' recovery in the context of other variables. Suggestions for future research on social reactions of others to adult survivors disclosing child sexual abuse are presented.     

Equal Opportunities Policies,Employment and Patriarchy

This paper, based on research in the North of England, seeks to examine the interconnections between equal opportunities policies, women's employment and patriarchy in a local labour market. It is argued that organizations develop a selection of public patriarchal strategies, most notable of which are the denial of inequality and the use of ‘time’ to segregate and disadvantage women within the labour market and labour process. It is masculine culture which has determined the shape and operation of equal opportunities policies where time commitment, individualism and priority to employment are necessary in order to achieve. Equal opportunities policies fail to address not only structural inequalities but also the role that organizations themselves play in maintaining gender segregation. By individualizing women the policies may also undermine women's own employment coping strategies which depend on assistance from other women both inside and outside the employment setting.     

AMERICAN GREETINGS: HAND SIGNALING ON THE HIGHWAYS

We describe and interpret hand signaling on the highways of the United States as a form of symbolic interaction. Results of this observational case study suggest that hand signaling is most frequently encountered in some sparsely populated regions of North America and is characterized by behaviors similar to those observed in comparable situated activity systems.     

Combination of Cancer Data in Quantitative Risk Assessments: Case Study Using Bromodichloromethane

There are often several data sets that may be used in developing a quantitative risk estimate for a carcinogen. These estimates are usually based, however, on the dose-response data for tumor incidences from a single sex/strain/species of animal. When appropriate, the use of more data should result in a higher level of confidence in the risk estimate. The decision to use more than one data set (e.g., representing different animal sexes, strains, species, or tumor sites) can be made following biological and statistical analyses of the compatibility of these data sets. Biological analysis involves consideration of factors such as the relevance of the animal models, study design and execution, dose selection and route of administration, the mechanism of action of the agent, its pharmacokinetics, any species- and/or sex-specific effects, and tumor site specificity. If the biological analysis does not prohibit combining data sets, statistical compatibility of the data sets is then investigated. A generalized likelihood ratio test is proposed for determining the compatibility of different data sets with respect to a common dose-response model, such as the linearized multistage model. The biological and statistical factors influencing the decision to combine data sets are described, followed by a case study of bromodichloromethane.