A Markov chain for calculating the durability of marriage

"The usual Markov model of marriage permits informative experiments on the effect of alterations in the transition rules. It can tell, for example, what difference it would make to the durability of marriage if there was no divorce and the other transitions were as observed. This is in addition to the capacity of the usual model to find the effect of small changes in the transition rates. Canadian data for 1970-1982 permit comparisons over time, and show among other things not only that married men live longer than single, but that the difference is increasing; the increase in the 'marriage bonus' over time also appears for women." (SUMMARY IN FRE)     

The Role of Maternal Behavior in the Relation between Shyness and Social Reticence in Early Childhood and Social Withdrawal in Middle Childhood

The moderating effect of maternal behavior in the relations between social reticence and shyness in preschool and subsequent social withdrawal was investigated. Eighty children (47 females) were judged for degree of social reticence during play with unfamiliar peers at the age of four and mothers completed the Colorado child temperament inventory (CCTI). At the age of seven, the children were coded for degree of social withdrawal during peer play and mothers and children were observed during structured and unstructured activities. Two significant interaction effects indicated that maternal report of shyness was a positive predictor of age‐seven social withdrawal when mothers lacked positivity; whereas observed social reticence was associated with higher degrees of social withdrawal when mothers were highly negative. Maternal positivity and negativity differentially influenced the development of social withdrawal in childhood, such that maternal negativity is associated with poor social functioning in children who have an established history of social withdrawal; whereas maternal positivity is associated with better social outcome for preschoolers who are viewed as temperamentally shy.     

Longitudinal patterns of anger reactivity and risk‐taking: The role of peer‐context

The current study examined the interplay between children's dispositional anger and susceptibility to peers' influence in increasing children's risk‐taking behaviors. Participants in the current study were children from a larger study of temperament and social–emotional development who were followed across 9, 24, 36, 48, and 60 months. Dispositional anger was measured using mothers' reports across 9 and 48 months. At 60 months, children played a risk‐taking computer game in presence of an unfamiliar peer who watched the child play. The child's risk‐taking was assessed during the game as the unfamiliar peers' reactions were coded based on comments that were peer directed, reflective of praising the target child's performance, or object directed, indicative of excitement toward the game. A latent profile analysis revealed three longitudinal anger profiles across infancy to early childhood: high stable, average stable, and low stable anger. Results suggested that as peers' object‐directed comments predicted risk‐taking independent of children's anger, the association between peer‐directed comments and risk‐taking was dependent on children's dispositional anger. Specifically, when peers praised the target child's performance, children in the high stable anger profile showed increased risk‐taking propensity. Findings are discussed based on the importance of considering both temperamental characteristics and aspects of the peer context in relation to children's risk‐taking.     

Leveraging historical data into oncology development programs: Two case studies of phase 2 Bayesian augmented control trial designs

Leveraging historical data into the design and analysis of phase 2 randomized controlled trials can improve efficiency of drug development programs. Such approaches can reduce sample size without loss of power. Potential issues arise when the current control arm is inconsistent with historical data, which may lead to biased estimates of treatment efficacy, loss of power, or inflated type 1 error. Consideration as to how to borrow historical information is important, and in particular, adjustment for prognostic factors should be considered. This paper will illustrate two motivating case studies of oncology Bayesian augmented control (BAC) trials. In the first example, a glioblastoma study, an informative prior was used for the control arm hazard rate. Sample size savings were 15% to 20% by using a BAC design. In the second example, a pancreatic cancer study, a hierarchical model borrowing method was used, which enabled the extent of borrowing to be determined by consistency of observed study data with historical studies. Supporting Bayesian analyses also adjusted for prognostic factors. Incorporating historical data via Bayesian trial design can provide sample size savings, reduce study duration, and enable a more scientific approach to development of novel therapies by avoiding excess recruitment to a control arm. Various sensitivity analyses are necessary to interpret results. Current industry efforts for data transparency have meaningful implications for access to patient‐level historical data, which, while not critical, is helpful to adjust for potential imbalances in prognostic factors.     

Individual mobility in a stationary population

An increasing population facilitates individual mobility. One of the consequences of moving towards the inevitable stationary population is that mobility will become more difficult.