Should we use logistic mixed model analysis for the effect estimation in a longitudinal RCT with a dichotomous outcome variable?

Background: Within epidemiology both mixed model analysis and Generalised Estimating Equations (GEE analysis) are frequently used to analyse longitudinal RCT data. With a continuous outcome, both methods lead to more or less the same results, but with a dichotomous outcome the results are totally different. The purpose of the present study is to evaluate the performance of a logistic mixed model analysis and a logistic GEE analysis and to give an advice which of the two methods should be used. Methods: Two real life RCT datasets with and without missing data were used to perform this evaluation. Regarding the logistic mixed model analysis also two different estimation procedures were compared to each other. Results: The regression coefficients obtained from the two logistic mixed model analyses were different from each other, but were always higher then the regression coefficients derived from a logistic GEE analysis. Because this also holds for the standard errors, the corresponding p-values were more or less the same. It was further shown that the effect estimates derived from a logistic mixed model analysis were an overestimation of the ‘real’ effect estimates. Conclusions:  Although logistic mixed model analysis is widely used for the analysis of longitudinal RCT data, this article shows that logistic mixed model analysis should not be used when one is interested in the magnitude of the regression coefficients (i.e. effect estimates)

Bidirectional Associations Between Coparenting Relations and Family Member Anxiety: A Review and Conceptual Model

Research into anxiety has largely ignored the dynamics of family systems in anxiety development. Coparenting refers to the quality of coordination between individuals responsible for the upbringing of children and links different subsystems within the family, such as the child, the marital relationship, and the parents. This review discusses the potential mechanisms and empirical findings regarding the bidirectional relations of parent and child anxiety with coparenting. The majority of studies point to bidirectional associations between greater coparenting difficulties and higher levels of anxiety. For example, the few available studies suggest that paternal and perhaps maternal anxiety is linked to lower coparental support. Also, research supports the existence of inverse links between coparenting quality and child anxiety. A child’s reactive temperament appears to have adverse effects on particularly coparenting of fathers. A conceptual model is proposed that integrates the role of parental and child anxiety, parenting, and coparenting, to guide future research and the development of clinical interventions. Future research should distinguish between fathers’ and mothers’ coparenting behaviors, include parental anxiety, and investigate the coparental relationship longitudinally. Clinicians should be aware of the reciprocal relations between child anxiety and coparenting quality, and families presenting for treatment who report child (or parent) anxiety should be assessed for difficulties in coparenting. Clinical approaches to bolster coparenting quality are called for.FSW – Publicaties zonder aanstelling Universiteit Leide

Just as they expected: How parents' expectations about their unborn child's characteristics provide a context for early transactions between parenting and child temperament

Prenatal expectations about what children will be like after birth may provide a context for how parents perceive their infant's actual temperament. We examined how these expectations and perceptions are associated and together predict early parenting behavior, with parenting behavior in turn predicting changes in temperament. Reports of 125 families (N = 122 fathers; N = 123 mothers; sample 1) about their expectations of their unborn child's temperament (negative affectivity, surgency, regulation, T1), their infant's temperament at 4 and 12 months post-partum (T2 and T3), and their hostile, responsive, warm, and overprotective parenting (T2) were included. We also included data from an independent sample of 168 mothers (sample 2), with the same measures, except that mothers reported on Big Five personality traits at T1. Results indicated that in both samples, parents' expectations were positively associated with perceptions of infant temperament. Prenatal expectations and newborn temperament independently predicted parenting behavior, and maternal and paternal parenting in turn predicted infant temperament at T3, controlling for infant temperament at T2. Although overall findings indicated associations between (expectations of) a more difficult temperament and more negative/less positive parenting, significant combinations of specific traits and parenting behaviors were sample-specific—indicating that more research is necessary to draw a conclusion about specific links. Both maternal and paternal expectations about their unborn child's temperament appear to carry over into the postpartum reality and provide a context for shaping early interactions between caregivers and their children, which may further shape the developing temperament of the child

Longitudinal associations between sleep and anxiety during pregnancy, and the moderating effect of resilience, using parallel process latent growth curve models

Background: For many women, pregnancy-related sleep disturbances and pregnancy-related anxiety change as pregnancy progresses and both are associated with lower maternal quality of life and less favorable birth outcomes. Thus, the interplay between these two problems across pregnancy is of interest. In addition, psychological resilience may explain individual differences in this association, as it may promote coping with both sleep disturbances and anxiety, and thereby reduce their mutual effects. Therefore, the aim of the current study was to examine whether sleep quality and sleep duration, and changes in sleep are associated with the level of and changes in anxiety during pregnancy. Furthermore, the study tested the moderating effect of resilience on these associations.Methods: At gestational weeks 14, 24, and 34, 532 pregnant women from the FinnBrain Birth Cohort Study in Finland filled out questionnaires on general sleep quality, sleep duration and pregnancy-related anxiety; resilience was assessed in week 14.Results: Parallel process latent growth curve models showed that shorter initial sleep duration predicted a higher initial level of anxiety, and a higher initial anxiety level predicted a faster shortening of sleep duration. Changes in sleep duration and changes in anxiety over the course of pregnancy were not related. The predicted moderating effect of resilience was not found.Conclusions: The results suggested that pregnant women reporting anxiety problems should also be screened for sleeping problems, and vice versa, because women who experienced one of these pregnancy-related problems were also at risk of experiencing or developing the other problem. (C) 2017 Elsevier B.V. All rights reserved.</p

Social anxiety symptoms in young children:Investigating the interplay of theory of mind and expressions of shyness

Children’s early onset of social anxiety may be associated with their social understanding, and their ability to express emotions adaptively. We examined whether social anxiety in 48-month-old children (N = 110; 54 boys) was related to: a) a lower level of theory of mind (ToM); b) a lower proclivity to express shyness in a positive way (adaptive); and c) a higher tendency to express shyness in a negative way (non-adaptive). In addition, we investigated to what extent children’s level of social anxiety was predicted by the interaction between ToM and expressions of shyness. Children’s positive and negative expressions of shyness were observed during a performance task. ToM was measured with a validated battery, and social anxiety was assessed using both parents’ reports on questionnaires. Socially anxious children had a lower level of ToM, and displayed more negative and less positive shy expressions. However, children with a lower level of ToM who expressed more positive shyness were less socially anxious. Additional results show that children who displayed shyness only in a negative manner were more socially anxious than children who expressed shyness only in a positive way and children who did not display any shyness. Moreover, children who displayed both positive and negative expressions of shyness were more socially anxious than children who displayed shyness only in a positive way. These findings highlight the importance of ToM development and socio-emotional strategies, and their interaction, on the early development of social anxiety

Hybrid models were found to be very elegant to disentangle longitudinal within- and between-subject relationships

Objectives: The interpretation of a regression coefficient obtained from a longitudinal data analysis is a combination of a within-subject part and a between-subject part. The hybrid model is used to disentangle the two components. The purpose of this article was to illustrate and discuss the use of the hybrid model in epidemiologic studies. Study Design and Setting: In the hybrid model the between-subject part of the relationship is obtained using the individual mean value over time, whereas the within-subject part is obtained using the deviation score, that is, the differences between the observations and the individual mean value. Results: It was shown that the regression coefficient of a standard mixed model analysis is a sort of weighted average of the between- and within-subject part of the relationship. When the outcome was continuous the separate analyses to estimate the two components of a longitudinal relationship were equal to the estimation in the hybrid model. However, for dichotomous outcome, the estimations were slightly different. Conclusion: The hybrid model is an elegant, easy to perform method to disentangle the within- and between-subject part of a relationship in longitudinal studies