Reducing sample size needed for cox-proportional hazards model analysis using more efficient sampling method

Abstract

In general, survival data are time-to-event data, such as time to death, time to appearance of a tumor, or time to recurrence of a disease. Models for survival data have frequently been based on the proportional hazards model, proposed by Cox. The Cox model has intensive application in the field of social, medical, behavioral and public health sciences. In this paper we propose a more efficient sampling method of recruiting subjects for survival analysis. We propose using a Moving Extreme Ranked Set Sampling (MERSS) scheme with ranking based on an easy-to-evaluate baseline auxiliary variable known to be associated with survival time. This paper demonstrates that this approach provides a more powerful testing procedure as well as a more efficient estimate of hazard ratio than that based on simple random sampling (SRS). Theoretical derivation and simulation studies are provided. The Iowa 65+ Rural study data are used to illustrate the methods developed in this paper.     

Cyclical Evolution of the Global Right

An understanding of the current right‐wing national and transnational social movements can benefit from comparing them to the global and national conditions operating during their last appearance in the first half of the twentieth century and by carefully comparing twentieth‐century fascism with the neofascist and right‐wing populist movements that have been emerging in the twenty‐first century. This allows us to assess the similarities and differences, and to gain insights about what could be the consequences of the reemergence of populist nationalism and fascist movements. Our study uses the comparative evolutionary world‐systems perspective to study the Global Right from 1800 to the present. We see fascism as a form of capitalism that emerges when the capitalist project is in crisis. World historical waves of right‐wing populism and fascism are caused by the cycles of globalization and deglobalization, the rise and fall of hegemonic core powers, long business cycles (the Kondratieff wave), and interactions with both Centrist Liberalism and the Global Left. We consider how crises of the global capitalist system have produced right‐wing backlashes in the past, and how a future terminal crisis of capitalism could lead to a reemergence of a new form of authoritarian global governance or a reorganized global democracy in the future.     

Beyond tail median and conditional tail expectation: Extreme risk estimation using tail Lp-optimization

The conditional tail expectation (CTE) is an indicator of tail behavior that takes into account both the frequency and magnitude of a tail event. However, the asymptotic normality of its empirical estimator requires that the underlying distribution possess a finite variance; this can be a strong restriction in actuarial and financial applications. A valuable alternative is the median shortfall (MS), although it only gives information about the frequency of a tail event. We construct a class of tail L^p-medians encompassing the MS and CTE. For p in (1,2), a tail L^p-median depends on both the frequency and magnitude of tail events, and its empirical estimator is, within the range of the data, asymptotically normal under a condition weaker than a finite variance. We extrapolate this estimator and another technique to extreme levels using the heavy-tailed framework. The estimators are showcased on a simulation study and on real fire insurance data.     

Cohabitation and commitment: partnership plans of young men and women

Popular commentators on marriage and the family often interpret the increase in heterosexual couples living together without marrying as reduced willingness to create and honour life‐long partnerships. Survey and in‐depth interviews with samples of 20–29 year olds living in an urban area of Scotland finds little support for the postulated link between growing cohabitation and a weakened sense of commitment to long‐term arrangements. Most of the cohabiting couples strongly stressed their ‘commitment’. Socially acceptable vocabularies of motive undoubtedly influenced answers but interviews helped to explore deeper meanings. Many respondents’ views were consistent with previous research predictions of a weakening sense of any added value of marriage. At the same time, some respondents continued to stress the social significance of the distinction between marriage and cohabitation, consistent with research interpreting cohabitation as a ‘try and see’ strategy part‐way to the perceived full commitment of marriage. The notion that ‘marriage is better for children’ continued to have support among respondents. While, on average, cohabiting couples had lower incomes and poorer employment situations than married couples, only very extreme adverse circumstances were presented as making marriage ‘too risky’. Pregnancy‐provoked cohabitation was not always in this category. Cohabitation was maintained because marriage would ‘make no difference’ or because they ‘had not yet got round to’ marriage. Most respondents were more wary of attempting to schedule or plan in their personal life than in other domains and cohabitees’ attitudes to partnership, including their generally ‘committed’ approach, do not explain the known greater vulnerability of this group to dissolution.     

Family Ties and Peso Signs: Challenges for Career Counseling in the Philippines

The article's 1st section provides an overview of the historical development of career counseling in the Philippines from an economic‐political perspective. The 2nd section raises current challenges and concerns, highlighting the need for a career counseling model that would address, among other things, Filipinos' valued characteristics of close family ties and desire for economic progress.