Simple Formulae for Evaluating the Potential Impact of Confounding Bias

Unmeasured confounding is a common problem in observational studies. This article presents simple formulae that can set the bounds of the confounding risk ratio under three standard populations of the exposed, unexposed, and total groups. The bounds are derived by considering the confounding risk ratio as a function of the prevalence of a covariate, and can be constructed using only information about either the exposure–confounder or the disease–confounder relationship. The formulae can be extended to the confounding odds ratio in case–control studies, and the confounding risk difference is discussed. The application of these formulae is demonstrated using an example in which estimation may suffer from bias due to population stratification. The formulae can help to provide a realistic picture of the potential impact of bias due to confounding.     

Monte-Carlo Sensitivity Analysis for Controlled Direct Effects Using Marginal Structural Models in the Presence of Confounded Mediators

In randomized trials, investigators are frequently interested in estimating the direct effect of a treatment on an outcome that is not relayed by intermediate variables, in addition to the usual intention-to-treat (ITT) effect. Even if the ITT effect is not confounded due to randomization, the direct effect is not identified when unmeasured variables affect the intermediate and outcome variables. Although the unmeasured variables cannot be adjusted for in the models, it is still important to evaluate the potential bias of these variables quantitatively. This article proposes a sensitivity analysis method for controlled direct effects using a marginal structural model that is an extension of the sensitivity analysis method of unmeasured confounding introduced in the context of observational studies. The proposed method is illustrated using a randomized trial of depression.     

从公共哲学的视野看日本和平宪法

战后日本,三种公共哲学最具有影响力,它们是立宪主义的民主主义与和平主义,经济发展和新民族主义.和平宪法存在天皇制等历史局限性和问题.和平宪法的现实主义因素有:对本国政府和军队的怀疑主义,原子弹受害经验,国家主权的自主限制,新国民原理等,和平宪法维护了日本战后60年没有发动过战争,防止了军国主义的复活,保持了"和平国家"的形象,战后的民主主义与和平主义没有国民的精力和国家资源使用到军事方面等是不容忽视的重要事实.     

An Approach for Estimating Causal Effects in Randomized Trials with Noncompliance

We developed methods for estimating the causal risk difference and causal risk ratio in randomized trials with noncompliance. The developed estimator is unbiased under the assumption that biases due to noncompliance are identical between both treatment arms. The biases are defined as the difference or ratio between the expectations of potential outcomes for a group that received the test treatment and that for the control group in each randomly assigned group. Although the instrumental variable estimator yields an unbiased estimate under a sharp null hypothesis but may yield a biased estimate under a non-null hypothesis, the bias of the developed estimator does not depend on whether this hypothesis holds. Then the estimate of the causal effect from the developed estimator may have a smaller bias than that from the instrumental variable estimator when the treatment effect exists. There is not yet a standard method for coping with noncompliance, and thus it is important to evaluate estimates under different assumptions. The developed estimator can serve this purpose. Its application to a field trial for coronary heart disease is provided.     

Perspectives of South African caregivers in receipt of Child Support Grants: Implications for family strengthening interventions

Cash transfers have delivered measurable benefits for poor and vulnerable children in low‐ and middle‐income countries. However, on its own, a cash transfer is insufficient to promote holistic child well‐being. In the quest for appropriate complementary family support services, known as ‘cash plus’ programing, this qualitative study sought to explore the perspectives of a group of South African caregivers, all of whom were in receipt of a Child Support Grant (CSG), in relation to their own caregiving and family functioning. Critical areas of support to families were identified to further scale up the already positive impacts of the CSG, such as mental health services, social supports for caregivers, decreasing levels of poverty and growing caregiving knowledge and skills. Key conclusions are that improving the quality and integration of public services and developing culturally appropriate and evidence‐based family strengthening programmes are critical to complement and boost the positive impacts of the CSG.     

Aggression exhibited by older dementia clients toward staff in Japanese long-term care

This study examined the experiences of staff members from seven Japanese hospitals who had been treated aggressively by older dementia clients. Altogether, 170 questionnaires were analyzed. In the past year, 75.3% and 63.5% of staff members had experienced physical and verbal aggression, respectively. Working numerous night shifts, working shifts other than 3-shifts, and being allotted assignments with clients who had a lower average level of physical capacity were the factors associated with recurrent client aggression. Those staff members who spent adequate time caring for their clients, who gained client consent before providing care, and who tried to build a trusting relationship with their clients were found to have experienced less aggression. Burnout, which is likely to enhance the risk of the staff mistreatment and neglect of older clients, was found to be higher among those who experienced aggression.