Determinants of the Annual Duration of Sickness Presenteeism: Empirical Evidence from European Data

Sickness presenteeism, i.e. going to work while sick, can cause substantial productivity losses. Focusing on work‐related characteristics, we investigate the determinants of the annual duration of sickness presenteeism using representative European cross‐sectional data. We find work autonomy, workload, tenure, and the work environment to be the quantitatively most relevant determinants of sickness presenteeism days. Work autonomy (control over one's work, being supervisor), workload (weekly working hours, time pressure), and tenure are positively related to the number of sickness presenteeism days. In contrast, a good work environment (good working conditions and social support) comes along with fewer presenteeism days.     

The effect of World War I and the 1918 influenza pandemic on cohort life expectancy of South Australian males born in 1881–1900

Cohort lifetime distribution functions have been estimated for the twenty separate calendar year cohorts of South Australian males born in 1881–1900. A cohort life expectancy at birth was calculated from each of these distribution functions, and a composite assessment made of the reduction in cohort life expectancy at birth due to both World War I 1914–1918 and the 1918 Influenza Pandemic. By partitioning each cohort, the cohort life expectancy at birth of the subgroup that had overseas military service is estimated to be 85 to 90 per cent of the cohort life expectancy at birth of the subgroup that remained in South Australia.     

A closed testing procedure for comparing successive exponential populations with respect to location parameter

Consider k independent random samples such that i^th sample is drawn from a two-parameter exponential population with location parameter μ_i and scale parameter θ_i,?i = 1, …, k. For simultaneously testing differences between location parameters of successive exponential populations, closed testing procedures are proposed separately for the following cases (i) when scale parameters are unknown and equal and (ii) when scale parameters are unknown and unequal. Critical constants required for the proposed procedures are obtained numerically and the selected values of the critical constants are tabulated. Simulation study revealed that the proposed procedures has better ability to detect the significant differences and has more power in comparison to exiting procedures. The illustration of the proposed procedures is given using real data.     

Estimation and prediction for an inverted exponentiated Rayleigh distribution under hybrid censoring

In this paper we consider estimation of unknown parameters of an inverted exponentiated Rayleigh distribution when it is known that data are hybrid Type I censored. The maximum likelihood and Bayes estimates are derived. In sequel interval estimates are also constructed. We further consider one- and two-sample prediction of future observations and also obtain prediction intervals. The performance of proposed methods of estimation and prediction is studied using simulations and an illustrative example is discussed in support of the suggested methods.     

Time-to-event calibration-free odds design: A robust efficient design for phase I trials with late-onset outcomes

Compared with most of the existing phase I designs, the recently proposed calibration-free odds (CFO) design has been demonstrated to be robust, model-free, and easy to use in practice. However, the original CFO design cannot handle late-onset toxicities, which have been commonly encountered in phase I oncology dose-finding trials with targeted agents or immunotherapies. To account for late-onset outcomes, we extend the CFO design to its time-to-event (TITE) version, which inherits the calibration-free and model-free properties. One salient feature of CFO-type designs is to adopt game theory by competing three doses at a time, including the current dose and the two neighboring doses, while interval-based designs only use the data at the current dose and is thus less efficient. We conduct comprehensive numerical studies for the TITE-CFO design under both fixed and randomly generated scenarios. TITE-CFO shows robust and efficient performances compared with interval-based and model-based counterparts. As a conclusion, the TITE-CFO design provides robust, efficient, and easy-to-use alternatives for phase I trials when the toxicity outcome is late-onset.     

CRITICAL PERIODS DURING CHILDHOOD AND ADOLESCENCE

We identify the ages that constitute sensitive (or critical) periods in children's development towards their adult health status, skills, and human capital. For this, we use data on families migrating into Sweden from countries that are poorer, with less healthy conditions. Late‐life health is proxied by adult height and other adult outcomes. The relation between siblings’ ages at migration and their adult outcomes allows us to estimate the causal effect of conditions at specific childhood ages. We effectively exploit that, for siblings, the migration occurs simultaneously in calendar time but at different developmental stages (ages). We find evidence that the period just before the puberty growth spurt constitutes a critical period for adult height and we find related critical periods for adult cognition, mental health, and education.     

长江经济带城市制造业集聚的空间外部性:识别与应用

文章运用双变量莫兰指数研究了长江经济带130个城市制造业集聚的空间外部性。首先，测算了城市的经济发展指数和环境污染指数，以制造业为中心变量运用双变量莫兰指数测算了制造业与城市经济发展指数以及环境污染指数间的空间自相关性，得到了长江经济带上表现出经济外部性和环境外部性的城市；其次，从影响城市特征属性的因素出发，通过城市区位、城市发展定位与规划以及城市科技创新能力等因素分析了城市空间外部性的产生机理；最后，在识别具体城市外部性类型与表现的基础上，从城市政策体系、资源信息、产业结构和生态环境几个方面提出了对城市制造业空间外部性的应用，实现长江经济带城市空间联动效应。     

Should the two-trial paradigm still be the gold standard in drug assessment?

Two significant pivotal trials are usually required for a new drug approval by a regulatory agency. This standard requirement is known as the two-trial paradigm. However, several authors have questioned why we need exactly two pivotal trials, what statistical error the regulators are trying to protect against, and potential alternative approaches. Therefore, it is important to investigate these questions to better understand the regulatory decision-making in the assessment of drugs' effectiveness. It is common that two identically designed trials are run solely to adhere to the two-trial rule. Previous work showed that combining the data from the two trials into a single trial (one-trial paradigm) would increase the power while ensuring the same level of type I error protection as the two-trial paradigm. However, this is true only under a specific scenario and there is little investigation on the type I error protection over the whole null region. In this article, we compare the two paradigms by considering scenarios in which the two trials are conducted in identical or different populations as well as with equal or unequal size. With identical populations, the results show that a single trial provides better type I error protection and higher power. Conversely, with different populations, although the one-trial rule is more powerful in some cases, it does not always protect against the type I error. Hence, there is the need for appropriate flexibility around the two-trial paradigm and the appropriate approach should be chosen based on the questions we are interested in.     

Sample size re-estimation in Phase 2 dose-finding: Conditional power versus Bayesian predictive power

Unblinded sample size re-estimation (SSR) is often planned in a clinical trial when there is large uncertainty about the true treatment effect. For Proof-of Concept (PoC) in a Phase II dose finding study, contrast test can be adopted to leverage information from all treatment groups. In this article, we propose two-stage SSR designs using frequentist conditional power (CP) and Bayesian predictive power (PP) for both single and multiple contrast tests. The Bayesian SSR can be implemented under a wide range of prior settings to incorporate different prior knowledge. Taking the adaptivity into account, all type I errors of final analysis in this paper are rigorously protected. Simulation studies are carried out to demonstrate the advantages of unblinded SSR in multi-arm trials.     

Measuring economic competence of youth with a short scale

We present a 12-item scale measuring the cognitive component of economic competence and document the psychometric properties of the scale. Using a data set with >12,000 secondary school students in Germany, the scale shows high discriminatory power and covers a wide range of ability levels. Analyses of ‘Differential Item Functioninǵ show no item bias across key demographic characteristics, and scores show meaningful associations with scores obtained from adjacent test instruments. Student-level correlates mirror estimates documented in earlier literature as well as results relying on a more extensive version of the scale with 31 items. The presented short scale enables researchers and practitioners to efficiently measure economic competence of youth.