Sample size calculations for noninferiority trials for time-to-event data using the concept of proportional time

Noninferiority trials intend to show that a new treatment is ‘not worse'' than a standard-of-care active control and can be used as an alternative when it is likely to cause fewer side effects compared to the active control. In the case of time-to-event endpoints, existing methods of sample size calculation are done either assuming proportional hazards between the two study arms, or assuming exponentially distributed lifetimes. In scenarios where these assumptions are not true, there are few reliable methods for calculating the sample sizes for a time-to-event noninferiority trial. Additionally, the choice of the non-inferiority margin is obtained either from a meta-analysis of prior studies, or strongly justifiable ‘expert opinion'', or from a ‘well conducted'' definitive large-sample study. Thus, when historical data do not support the traditional assumptions, it would not be appropriate to use these methods to design a noninferiority trial. For such scenarios, an alternate method of sample size calculation based on the assumption of Proportional Time is proposed. This method utilizes the generalized gamma ratio distribution to perform the sample size calculations. A practical example is discussed, followed by insights on choice of the non-inferiority margin, and the indirect testing of superiority of treatment compared to placebo.KEYWORDS: Generalized gamma, noninferiority, non-proportional hazards, proportional time, relative time, sample size     

Developing Country Debt Research: Where Do We Go From Here?

Book reviewed in this article: Managing World Debt. Edited by S . Griffith-Jones International Capital Markets: Developments and Prospects. By an IMF Staff Team Multilateral Official Debt Rescheduling: Recent Experience. By P.M. Keller with N.E. Weerasinghe African Debt: The Case for Relief for Sub-Saharan Africa. By P.S. Mistry The International Debt Crisis of the Third World. By P. Nunnenkamp. The African Debt Crisis. By T.W. Parfitt and S.P. Riley Developing Country Debt: the Budgetary and Transfer Problem. By H. Reisen and A. van Trotsenburg Latin American Debt and the Adjustment Crisis. Edited by R. Thorp and L. Whitehead Voluntary Approaches to Debt Relief. By J. Williamson     

White Ethnic Diversity in Small Town Iowa: A Multilevel Analysis of Community Attachment

Community attachment is the feeling of being connected to community life. Within the community attachment literature, two classic approaches frame scholars’ understanding of this important dimension of community life: the linear development and systemic models. Our empirical models emphasize different factors for community attachment, including population size, density, and heterogeneity for the linear development model and age, length of residence, and social status for the systemic model. Surprisingly, heterogeneity has been omitted from analyses of the linear development model throughout the literature since its introduction, a shortcoming our study addresses. Though heterogeneity can be conceptualized in a number of ways, a large—and growing—body of literature focuses on the effects of race and ethnicity for communities. Here, we focus on a particular type of ethnic heterogeneity—European ancestry—and reincorporate this essential dimension of communities back into the linear development model of community attachment. Using data from the 2004 wave of the Iowa Community Survey and multilevel modeling techniques, we explore how white ethnic diversity matters for community life. We conclude with a discussion of the implications of our study, including potential avenues for future research focusing on other ethnicities that are often subsumed under broader racial and panethnic labels.     

Whose ‘wee country’?: identity politics and sport in Northern Ireland

This article responds to calls in this journal for increased attention to identity, culture, power and sport. It explores, for the first time, the lived realities of identity politics in a divided society, through interviews with 12 self-declared Irish nationalists and republicans that represented Northern Ireland. Important insights are revealed into national eligibility decisions for either Irish team, motivated mainly by ‘shop window’ visibility and being seen as the best of a peer group. Political and sporting nationalisms were not necessarily analogous. A significant original finding is that the lived experiences of being closer to ‘the other’ resulted in an overall reinforcement rather than dissolution of difference. Visual and oral ‘national’ symbols such as flag, and especially anthem, delineated such difference, being symbolic walls of the mind. ‘Our wee country’ was thus a polarised and polarising fantasy shield. The article concludes by reconsidering the role of sport as a lens through which to examine identity and its’ place as part of the ‘problem’ and ‘solution’.     

Variation in age,body size,and reproductive traits among urban and rural amphibian populations

Urban Ecosystems - Although amphibians use human-created habitats in urban landscapes, few studies have investigated the quality of these habitats. To assess habitat quality of stormwater...     

Wanting To Be Remembered: Intrinsically Rewarding Work and Generativity in Early Midlife

Previous research on generativity, the desire to leave a legacy through establishing and guiding the next generation, has focused primarily on family life and civic engagement as pathways to midlife generativity. This paper proposes that intrinsically rewarding work can also be associated with a heightened sense of generativity in midlife. We test this hypothesis with data (n = 369 employed individuals, approximately 43 years old) from the 2010 wave of the Edmonton Transitions Study. Civic engagement was positively associated with midlife generativity, as predicted, but the hypothesized positive relationship between generativity and perceived parenting success was not found. Taking into account civic engagement and perceived parenting success, and controlling on a range of other variables, intrinsically rewarding work was positively associated with midlife feelings of generativity.     

“With Whom no White Scholar can Compare”: Academic Interpretations of the Relationship between W.E.B. Du Bois and Max Weber

Max Weber (1864–1920) is considered one of the canonical founders of sociology, while W. E. B. Du Bois (1868–1963), author of The Philadelphia Negro (1899), The Souls of Black Folk (1903), and Black Reconstruction (1935), has only recently been included in the sociological canon. We provide a historical review of what we know of their relationship in order to first ask, what did Du Bois say about Weber, and second, what did Weber say about Du Bois? We then analyze the extant scholarly discourse of published English-language academic journal articles that substantively mention both Weber and Du Bois in order to address a third question: what did other scholars say about their relationship? We provide an analysis of the variation of scholars’ perceptions on the relationship between Du Bois and Weber to illumine the dominant assumptions about founding figures and the origin story of American sociology writ large. We argue that three mechanisms of white group interests configured the marginalization of Du Bois from both mainstream and sub-disciplinary sociological theory: (1) reduction or “knowing that we do no know and not caring to know” (when knowledge is perceived as irrelevant to white group interests), (2) deportation or “not wanting to know” (when knowledge is systematically exiled), and (3) appropriation or “not knowing that we do not know”) (when dominant knowledge usurps or assimilates challenges to that knowledge).     

Toward Father‐friendly Parenting Interventions: A Qualitative Study

Levels of father participation in parenting interventions are often very low, yet little is known about the factors which influence father engagement. We aimed to qualitatively explore perceived barriers to, and preferences for, parenting interventions in a community sample of fathers. Forty‐one fathers across nine focus groups were interviewed using a semi‐structured interview. Data were analysed using inductive thematic analysis. Key barriers to father participation identified included: the perception that interventions are mother‐focused; beliefs about gender roles regarding parenting and help‐seeking; mothers’ role as ‘gatekeeper’; lack of knowledge and awareness of parenting interventions; and lack of relevance of interventions. Fathers reported preferences for specific content and intervention features, facilitator characteristics, practical factors, and highlighted the need for father‐targeted recruitment and advertising. Many of the barriers and preferences identified are consistent with previous research; however, fathers’ beliefs and attitudes around gender roles and help‐seeking, as well as the perception that interventions are predominantly mother‐focused, may be key barriers for community fathers. Strategies to overcome these barriers and better meet the needs of fathers in promoting and delivering parenting interventions are discussed.