Analysis of error-prone survival data under additive hazards models: measurement error effects and adjustments

Covariate measurement error occurs commonly in survival analysis. Under the proportional hazards model, measurement error effects have been well studied, and various inference methods have been developed to correct for error effects under such a model. In contrast, error-contaminated survival data under the additive hazards model have received relatively less attention. In this paper, we investigate this problem by exploring measurement error effects on parameter estimation and the change of the hazard function. New insights of measurement error effects are revealed, as opposed to well-documented results for the Cox proportional hazards model. We propose a class of bias correction estimators that embraces certain existing estimators as special cases. In addition, we exploit the regression calibration method to reduce measurement error effects. Theoretical results for the developed methods are established, and numerical assessments are conducted to illustrate the finite sample performance of our methods.     

Likelihood‐based and marginal inference methods for recurrent event data with covariate measurement error

Recurrent event data arise commonly in medical and public health studies. The analysis of such data has received extensive research attention and various methods have been developed in the literature. Depending on the focus of scientific interest, the methods may be broadly classified as intensity‐based counting process methods, mean function‐based estimating equation methods, and the analysis of times to events or times between events. These methods and models cover a wide variety of practical applications. However, there is a critical assumption underlying those methods–variables need to be correctly measured. Unfortunately, this assumption is frequently violated in practice. It is quite common that some covariates are subject to measurement error. It is well known that covariate measurement error can substantially distort inference results if it is not properly taken into account. In the literature, there has been extensive research concerning measurement error problems in various settings. However, with recurrent events, there is little discussion on this topic. It is the objective of this paper to address this important issue. In this paper, we develop inferential methods which account for measurement error in covariates for models with multiplicative intensity functions or rate functions. Both likelihood‐based inference and robust inference based on estimating equations are discussed. The Canadian Journal of Statistics 40: 530–549; 2012 © 2012 Statistical Society of Canada     

Household Income and Trajectories of Marital Satisfaction in Early Marriage

Are the marriages of lower income couples less satisfying than the marriages of more affluent couples? To address this question, we compared trajectories of marital satisfaction among couples with a wide range of household incomes. The marital satisfaction of 862 Black, White, and Latino newlywed spouses (N = 431 couples) was assessed five times, each 9 months apart, during the first 4 years of marriage. Lower income couples did not have less satisfying marriages on average, nor did their satisfaction decline more steeply on average. They did, however, experience (a) significantly greater fluctuations in marital satisfaction across assessments and (b) significantly more variability between husbands and wives. If efforts to support the marriages of low‐income couples are to address the unique characteristics of their marital development, these findings suggest that efforts to stabilize their marriages may be more effective than efforts to improve their satisfaction alone.     

Chinese Singaporean attitudes towards poverty and inequality: A comparative analysis

Ng IYH, Koh G. Chinese Singaporean attitudes towards poverty and inequality: a comparative analysis Based on a survey of 191 Chinese respondents, this article discusses the attitudes of Singaporean Chinese towards poverty, inequality and government intervention. Using the Z‐test for two proportions and cluster analysis, findings were compared with similar studies in the USA and the UK. Chinese Singaporeans were found to be very aware of the growing inequality, but they adopted a narrower definition of poverty than British respondents. This might be the reason why they were more sympathetic towards the poor and supportive of more government anti‐poverty efforts than were American respondents. From the cluster analysis, the Singaporean sample produced a third group who were ‘satisfied but concerned’, on top of the two polar groups, ‘sceptics’ and ‘liberals’, present in the British study. A majority of respondents also supported the view that more should be done to help the poor and were willing to pay more taxes for that purpose.     

“Taking Mama Steps” Toward Authority,Alternatives, and Advocacy

Ten years ago, the task of blending work and motherhood was arduous, lonely, and painstaking. Most settled for face-to-face interactions or phone calls to friends and family for support. Sadly, frustrated conversations are still happening due to a lack of cultural acceptance, policies, and laws focused on blending work and family life. However, some women are turning to online spaces for social support. In 1991, Donna Haraway posited that online, affinity-based groups contain the potential for activism. Buoyed by digital social media possibilities for social support, we assessed feminist activism within a motherhood support group populated by women from various countries around the world. We found that consciousness-raising can further feminist activism within an online motherhood Facebook group by helping others learn to negotiate their choices, but economic stratification and educational divides still constrain social support; this suggests that digital connections influence affinity-based identities and feminist activism.     

Investigating Adolescent Health-Related Quality of Life: From a Self-Identity Perspective

The aim of the study was to investigate the relation between self-identity and health-related quality of life (HRQOL) in adolescence. This study assumed that four aspects (i.e. personal, social, ability, and academic identity) of identity firmness could predict adolescent’s HRQOL more than four aspects of identity importance. Meanwhile, this study also hypothesized that psychological and social relationships domains of HRQOL could be largely explained by the concept of identity firmness. One hundred and ninety-eight female adolescents participated in this study. Each participant completed a booklet containing the measures of the Questionnaire of revised edition of identity importance (QII-R), the Questionnaire of revised edition of identity firmness (QIF-R), the WHOQOL-BREF Taiwan version, and Visual-analogue HRQOL items. This study administered multiple regression analyses to test our hypotheses. The results demonstrated the concept of identity firmness could predict adolescent’s HRQOL more than the concept of identity importance. The results also supported our hypotheses that psychological and social relationships domains of HRQOL could be largely explained by the concept of identity firmness. In general, this study supported our hypotheses that the concept of identity firmness is a crucial predictor to adolescent’s HRQOL.     

Heterosexual Anal Intercourse among Men in Long Beach,California

Anal intercourse poses a greater risk for human immunodeficiency virus (HIV) transmission than vaginal intercourse, and in recent years there has been a growing understanding that heterosexual anal intercourse (HAI) is not uncommon. However, the majority of the anal intercourse literature has focused on men who have sex with men. The little research on HAI has mostly looked at women, with limited work among men. This analysis examined the association between HAI and high-risk behaviors (N = 1,622) and sexual sensation seeking (N = 239) in a sample of men recruited from 2001 to 2012 in Long Beach, California. Almost half of the sample was non-Hispanic Black. The median age was 42 years, 42% were homeless, and 20% reported recent HAI. Men who reported HAI were likely to be Hispanic, were likely to be homeless, had a male partner, engaged in sex exchange, and used cocaine or amphetamines during sex. Men who reported HAI scored higher on the Sexual Sensation Seeking scale. This research supports other work showing the relationship between HAI and high-risk behaviors. More important, it contributes new knowledge by demonstrating the association between HAI and sexual sensation seeking. This research highlights the importance of personality traits when trying to understand sexual behavior and when developing HIV prevention interventions.