Motivated by a breast cancer research program, this paper is concerned with the joint survivor function of multiple event times when their observations are subject to informative censoring caused by a terminating event. We formulate the correlation of the multiple event times together with the time to the terminating event by an Archimedean copula to account for the informative censoring. Adapting the widely used two-stage procedure under a copula model, we propose an easy-to-implement pseudo-likelihood based procedure for estimating the model parameters. The approach yields a new estimator for the marginal distribution of a single event time with semicompeting-risks data. We conduct both asymptotics and simulation studies to examine the proposed approach in consistency, efficiency, and robustness. Data from the breast cancer program are employed to illustrate this research.
Informal caregivers of individuals with Alzheimer's disease spend a considerable amount of time providing care. In this paper, we use Grossman's health production and Becker's time allocation models to develop a model of informal care provision to elderly dementia patients. In our model, time inputs produce caregiving services, which provides utility to the caregiver, but reduces leisure. We assume that time is less productive of services on the margin as the disease progresses. In this framework, an increase in patients' disease severity does not necessarily increase informal caregiver time input. The cost of formal care establishes a reservation price for informal caregiving. When the costs of informal caregiving rise above this reservation level, the patient is institutionalized. We test empirically the effect of deterioration in the patients' condition, proxied by both disease severity and dementia problem behavior, on informal caregiving time. We find that dementia-related problem behaviors and functional limitations significantly increase inputs of informal caregiving time. Patients' problem behavior exerts a modifying effect on functional limitations, and patients' comorbidities have no effect on informal caregiving time. 相似文献
In this article, we conduct a textual analysis of Edith Wharton's 1911 novel, Ethan Frome . We offer three readings. The first presents Wharton's account of illness through a framework developed foru decades later by Talcott Parsons. Wharton's sick role was less medico-centric than Parsons; it emphasized the importance of class, gender and community in defining and legitimizing the sick role. Our second reading explores the socially constructed nature of roles in illness. The sick role as portrayed by Wharton is not the social fact later conceived by Parsons, but a social construct with no determinate reference beyond that which the local community is willing to grant it. Our third reading examines the social context, particularly the power relations, within which this story of illness has been constructed. 相似文献
Using data from the National Longitudinal Study of Adolescent Health (Add Health), a nationally representative sample of youth from 7th to 12th grades, we examined how racial and ethnic identification overlap among Hispanic adolescents. We evaluated the relative proximity between race and ethnic identifiers among Hispanics. Empirical analyses suggest that the racial identification of other students at school has a significant impact on the odds of choosing particular racial identifiers. Both Hispanic and non-Hispanic schoolmates' racial identification is related to the racial identification of Hispanic adolescents. We also find evidence that both ethnicity and race are distinct stratifiers among Hispanics. Overall, our findings support the notion that Hispanic may be a more meaningful "racial" identity than black, white, or other, but we also find that racial identification and ethnic background are still important and meaningful dividers among Hispanic youth. 相似文献
Longitudinal data often contain missing observations, and it is in general difficult to justify particular missing data mechanisms, whether random or not, that may be hard to distinguish. The authors describe a likelihood‐based approach to estimating both the mean response and association parameters for longitudinal binary data with drop‐outs. They specify marginal and dependence structures as regression models which link the responses to the covariates. They illustrate their approach using a data set from the Waterloo Smoking Prevention Project They also report the results of simulation studies carried out to assess the performance of their technique under various circumstances. 相似文献
Using data from 8 random assignment studies and employing meta‐analytic techniques, this article provides systematic evidence that welfare and work policies targeted at low‐income parents have small adverse effects on some school outcomes among adolescents ages 12 to 18 years at follow‐up. These adverse effects were observed mostly for school performance outcomes and occurred in programs that required mothers to work or participate in employment‐related activities and those that encouraged mothers to work voluntarily. The most pronounced negative effects on school outcomes occurred for the group of adolescents who had a younger sibling, possibly because of the increased home and sibling care responsibilities they assumed as their mothers increased their employment. 相似文献
To prepare for the complexities of family formation, 78 prospective adoptive parents participated in Pre-Adopt, a psychosocial educational orientation program offered by one private nonprofit agency. The five-session curriculum included an overview of adoption policies and procedures, discussion of the child placement process, exploration of couples' adoption concerns and expectations about child characteristics, information about adoption laws and birth-parent/child searches, and examination of anticipatory fantasies about birth parents. Program evaluation yielded statistically significant and clinically meaningful findings about changes in emotional readiness to adopt, parenting knowledge, and satisfaction with group participation, adoption policies and agency practices. Practice implications are considered. 相似文献