Nonparametric analysis of recurrent gap time data

Abstract

Recurrent event data are frequently encountered in longitudinal studies. In many applications, the times between successive recurrent events (gap times) are often of interest and lead to problems that have received much attention recently. In this article, using the approach of inverse probability-of-censoring weights (IPCW), we propose nonparametric estimators for the estimation of the bivariate distribution and survival functions for gap times of recurrent event data. We also consider the estimation of Kendall’s tau for two gap times by expressing it as an integral functional of the bivariate survival function. The asymptotic properties of the proposed estimators are established. Simulation studies are conducted to investigate their finite sample performance.     

对布什政府在中东“反恐”期间美国国内相对团结的分析

"9.11事件"以后,美国先后出兵阿富汗和伊拉克,这个时期美国国内取得了空前的团结.这一方面是因为布什政府利用美国民众的愤怒和世界各国人民的同情,打着联合国旗号并编造伊拉克有大规模杀伤性武器的谎言,以维护民主和人权为旗号进行的战争;另一方面美国政府掠夺石油对美国居民也有利.舆论的诱导,使政府与居民的利益趋向相同.     

Patterns of Work and Schooling in Young Adulthood

If the years of late adolescence and early adulthood are depicted as rocky, disorderly, and experimental, then how should the life course stage that immediately follows be characterized? Using data from the National Longitudinal Study of the High School Class of 1972, we focus on work and school activities in the latter half of the young adult years (ages roughly 25–31) to empirically address whether the diversity of work and schooling patterns diminishes. Finding a lack of orderliness in work and schooling trajectories, and that holding two or more activities simultaneously is quite common, we question how this stage of the life course should be conceptualized. Moving away from the traditional sequential roles approach, we use multinomial logistic regression to differentiate among activity sequences commonly held by young men and women at these ages, and address how family of origin background factors and prior life experiences influence life course experiences in the later 20s and early 30s.

     

国家、区域政治与地方性：——以华北B镇“苯中毒”事件为例的多点民族志实验

2002年5月19日,国务院第352号令公布了《使用有毒物品作业 场所劳动保护条例》,从此,与有毒物打交道的劳动者除了已实施的《职 业病防治法》外,又多了一层法律保护网。该《条例》共分7章71条,包 括总则、作业场所的预防措施、劳动过程的防护、职业健康监督、劳动者 的权利与义务和监督管理和罚则等内容。由于此条例的诞生最初由华 北地区J省B镇1所发生的箱包工人"苯中毒"事件所促发,因而人称 "B镇条例"。在这起事件中,共有17名箱包工人中毒,其中5人死亡,     

Partial sufficient dimension reduction on joint model of recurrent and terminal events

Joint modeling of recurrent and terminal events has attracted considerable interest and extensive investigations by many authors. The assumption of low-dimensional covariates has been usually applied in the existing studies, which is however inapplicable in many practical situations. In this paper, we consider a partial sufficient dimension reduction approach for a joint model with high-dimensional covariates. Some simulations as well as three real data applications are presented to confirm and assess the performance of the proposed model and approach.     

Regression analysis of recurrent events data with incomplete observation gaps

For analyzing recurrent event data, either total time scale or gap time scale is adopted according to research interest. In particular, gap time scale is known to be more appropriate for modeling a renewal process. In this paper, we adopt gap time scale to analyze recurrent event data with repeated observation gaps which cannot be observed completely because of unknown termination times of observation gaps. In order to estimate termination times, interval-censored mechanism is applied. Simulation studies are done to compare the suggested methods with the unadjusted method ignoring incomplete observation gaps. As a real example, conviction data set with suspensions is analyzed with suggested methods.     

基于关联耦合法的水体污染公共安全事件诱发耦合模式研究

多因素的复杂耦合作用是水体污染公共安全事件诱发过程中的强大动力，运用关联耦合法，从宏观的关联耦合向量和中观的关联耦合变量两个层次梳理了水体污染公共安全事件诱因结构，并在此基础上分析得出了诱发因素之间的五种耦合作用方式。研究最后以松花江水污染事件为例，剖析上述五种耦合方式的变迁作用如何逐步推动事件的演化和发展。     

Screening for depression after cardiac events using the Beck Depression Inventory-II and the Geriatric Depression Scale

Despite findings that depression is a risk factor for heart disease and for death following cardiac events and that depressed cardiac patients experience significantly reduced quality of life and are less likely to follow treatment regimens, depression is neither adequately identified nor treated in cardiac patients. Recent calls in the literature for the use of standardized screening measures and sensitivity/specificity studies to identify useful measures compelled us to examine the sensitivity and specificity of the Beck Depression Inventory-II (BDI-II) and Geriatric Depression Scale (GDS) and recommend appropriate cut-scores for identifying depression in post-myocardial infarction or unstable angina patients. A total of 119 patients who met criteria for either acute myocardial infarction or unstable angina pectoris were recruited from coronary care units at three hospitals and interviewed in their homes approximately 2 weeks post-admission. The criterion used in the study was the Structured Clinical Interview for DSM-IV-TR Axis I Disorders (SCID-I/NP). Administration of the SCID-I/NP, BDI-II, and GDS was counterbalanced using a digram-balanced approach and blinded comparison was used. Alphas were .89 for BDI-II and .88 for GDS. For major depression, a BDI-II cut-score of 10 produced a sensitivity = 100%, specificity = 75%, and PPV = 18% whereas a GDS cut-score of 14 produced sensitivity = 100%, specificity = 94%, and PPV = 50%. For major/double depression, a BDI-II cut-score of 10 produced sensitivity = 100%, specificity = 75%, and PPV = 21% whereas a GDS cut-score of 13 produced sensitivity = 100%, specificity = 91%, and PPV = 41%. Although both measures demonstrated excellent reliability and sensitivity, the GDS showed better specificity and PPV and is recommended as the better screen for major depression or double depression with cardiac patients.     

Networks of action and events over time. A multilevel discrete-time event history model for longitudinal network data

Longitudinal network data recording the moment at which ties appear, change, or disappear are increasingly available. Event history models can be used to analyze the dynamics of time-stamped network data. This paper adapts the discrete-time event history model to social network data. A discrete-time event history model can easily incorporate a multilevel design and time-varying covariates. A multilevel design is needed to account for dependencies among ties and vertices, which should not be ignored in a small longitudinal network. Time-varying covariates are required to analyze network effects, that is, the impact of previous ties. In addition, a discrete-time event history model handles constraints on who can act or who can be acted upon in a straightforward way. The model can be estimated with multilevel logistic regression analysis, which is illustrated by an application to book reviews, so network evolution can be analyzed with a fairly standard statistical tool.     

ISO9000质量认证对我国企业财务绩效影响的实证研究——基于沪深上市公司的数据

以1992-2005年间通过ISO9000认证的我国上市公司为样本,运用事件研究法分析了ISO9000认证对我国企业财务绩效的影响。研究结果表明ISO9000认证对企业的市场绩效(销售增长率、总资产周转率)有一定的正向影响,而对企业的盈利能力及效率(销售净利率、销售成本率)没有积极影响。原因可能是我国企业的认证动机主要是以市场为导向,企业管理者对质量管理缺乏深入的理解以及ISO9000认证的成本过高等。