Analyzing preventive trials with generalized additive models

Described a new class of nonparametric regression procedures called generalized additive models (Hastie and Tibshirani, 1991) for assessing intervention effects in mental health preventive field trials. Such models are often better than analysis of covariance models for examining intervention effects adjusted for one or more baseline characteristics and for assessing potential interactions between the intervention and baseline characteristics. Because of these advantages, generalized additive models are important tools analysts should consider in evaluating preventive field trials. We apply generalized additive models as well as more standard linear models to data from a preventive trial aimed at improving mental health and school performance outcomes through a universal intervention in first and second grades. Practical guidance is given to researchers regarding when generalized additive models would be beneficial.     

Reducing the risk of bias in health behaviour change trials: Improving trial design,reporting or bias assessment criteria? A review and case study

Objective: It has been suggested that randomised controlled trials (RCTs) of health behaviour change (HBC) interventions are less rigorously designed than – for example– drug trials. This study presents an approach to clarifying whether this is due to poor trial design, incomplete trial reporting and/or the inappropriateness of commonly applied risk of bias assessment criteria.

Design: First, a framework of key sources of bias and common strategies for reducing bias risk is developed based on a literature review. Second, we describe the design of a multi-site RCT evaluating the cost-effectiveness of an HIV-treatment adherence intervention (case study). The choices made by the multidisciplinary team trying to minimise the risk of bias are compared against the risk of bias framework.

Main outcome measures: Implementation of common strategies for reducing the risk of bias in the case study; alternative or additional strategies applied; a justification for each deviation from the risk of bias framework.

Results: Most of the common strategies for reducing the risk of bias could be implemented. Alternative strategies were developed for minimising the risk of performance bias and contamination. Several additional, domain-specific risk of bias strategies were implemented.

Conclusions: The literature provides useful guidance for reducing the risk of bias in HBC trials. Yet, the case study suggests that HBC trial designers may face specific challenges that require alternative/additional measures for reducing the risk of bias. Using the risk of bias justification table (RATIONALE) could lead to better-designed HBC trials, more comprehensive trial reports and the data necessary for evaluating the appropriateness of commonly applied risk of bias assessment criteria to HBC trials.     

The Application of Latent Curve Analysis to Testing Developmental Theories in Intervention Research

The effectiveness of a prevention or intervention program has traditionally been assessed using time-specific comparisons of mean levels between the treatment and the control groups. However, many times the behavior targeted by the intervention is naturally developing over time, and the goal of the treatment is to alter this natural or normative developmental trajectory. Examining time-specific mean levels can be both limiting and potentially misleading when the behavior of interest is developing systematically over time. It is argued here that there are both theoretical and statistical advantages associated with recasting intervention treatment effects in terms of normative and altered developmental trajectories. The recently developed technique of latent curve (LC) analysis is reviewed and extended to a true experimental design setting in which subjects are randomly assigned to a treatment intervention or a control condition. LC models are applied to both artificially generated and real intervention data sets to evaluate the efficacy of an intervention program. Not only do the LC models provide a more comprehensive understanding of the treatment and control group developmental processes compared to more traditional fixed-effects models, but LC models have greater statistical power to detect a given treatment effect. Finally, the LC models are modified to allow for the computation of specific power estimates under a variety of conditions and assumptions that can provide much needed information for the planning and design of more powerful but cost-efficient intervention programs for the future.     

PATHS in Croatia: A school‐based randomised‐controlled trial of a social and emotional learning curriculum

This study represents the first rigorous evaluation of a social‐emotional learning curriculum, PATHS (P romoting A lternative Th inking S trategies; Kusché & Greenberg, 1994), in elementary schools in Croatia. This study randomly assigned 29 schools to receive the universal preventive intervention or continue with usual practices. Within those schools, this study included 57 classrooms and 568 children. Teachers rated nine child behaviours in the middle of first grade (pre‐intervention) and near the end of second grade (post‐intervention). Hierarchical linear models, nesting children within classrooms, revealed few changes in behaviour across the sample as a whole or among higher risk children. However, there were changes on eight of the nine behaviours for lower risk children. The findings are considered in the context of the classroom culture and teachers' preparation and readiness to implement a social‐emotional learning curriculum in Croatia. This study highlights the need to supplement universal preventive interventions with selective preventive interventions that can provide more intensive and targeted skill practice for higher risk children. This study also highlights the nuanced effects of a universal preventive intervention in helping different children in different ways.     

An Experimental Analysis of Reading Fluency

The experimental analysis of academic responding has emerged as one approach to strengthening decisions related to problem analysis and treatment design. This study provided an example of how both brief and extended assessments can be used within a data based, problem solving approach to addressing reading fluency concerns. For six children with reading difficulties, within-trial effects of various instructional strategies were used to identify and design interventions. Assessment-derived interventions were evaluated using weekly academic growth on general outcome measures. Results indicated that five of the six children responded favorably to intervention. Future research involving the contribution of experimental analysis to response to intervention models of service delivery is discussed.     

Imitative interaction increases social interest and elicited imitation in non‐verbal children with autism

Recent studies indicate that being intensely imitated for a brief period of time increases social interest among children with autism. The aim of this study was to replicate and extend these findings. Twenty children with an autism spectrum disorder (ASD) were randomly assigned to one of two interaction strategies: imitation (n=10) or contingent (n=10). The children had little or no functional speech, and their developmental age averaged 25 months (mean chronological age =6:5 years). Both conditions were presented with repeated sessions of a modified version of Nadel's ‘still‐face’ paradigm (still‐face/intervention/still‐face/spontaneous play). The analysis revealed a significant increase of both proximal and distal social behaviours (touch and look at person) for the imitation condition, which confirms previous reports. In addition, an increase in elicited imitation, as measured with the PEP‐R developmental assessment procedure, was also observed for children in the imitation condition, but not in the contingent condition. This finding extends earlier reports in that it suggests that the social expectancies unlocked by imitation also spread to tasks outside the experimental setting. Copyright © 2006 John Wiley & Sons, Ltd.     

Mediation analyses of Internet-facilitated cognitive behavioral intervention for maternal depression

This study evaluated the putative mediating mechanisms of an Internet-facilitated cognitive-behavioral therapy (CBT) intervention for depression tailored to economically disadvantaged mothers of preschool-age children. The CBT mediators were tested across two previously published randomized controlled trials which included the same measures of behavioral activation, negative thinking, and savoring of positive events. Trial 1 included 70 mothers with elevated depressive symptoms who were randomized to either the eight-session, Internet-facilitated intervention (Mom-Net) or to treatment as usual. Trial 2 included 266 mothers with elevated depressive symptoms who were randomized to either Mom-Net or to a motivational interviewing and referral to services condition. Simple mediation models tested each putative mediator independently followed by tests of multiple mediation that simultaneously included all three mediators in the model to assess the salient contributions of each mediator. The pattern of results for the mediating effects were systematically replicated across the two trials and suggest that behavioral activation and negative thinking are salient mediators of the Mom-Net intervention; significant mediating effects for savoring were obtained only in the simple mediation models and were not obtained in the multiple mediation models.     

Empowering public service workers to face bystander conflict: Enhancing resources through a training intervention

Public service employees work in occupations that are accompanied with high psychosocial risks. Police, firefighters, and paramedics are increasingly being confronted with argumentative, conflicting bystanders that frustrate them in executing their task. We developed a resource‐enhancement intervention and tested its usefulness for securing employees’ effective functioning and well‐being in bystander conflict. In a simulation‐based pre‐test post‐test control group design, paramedics in the intervention condition received training about how to increase their resources in terms of conflict management efficacy, perspective taking, task support, and emotional support. For those in the control condition, no such training was provided. Comparing pre‐ and post‐test measures (n = 81) of the participants in the intervention and control groups, we found evidence that the intervention successfully increased employees’ resources over time. Moreover, we found considerable support for a positive link between these resources and employees’ affective well‐being and job dedication. Thus, our study suggests that a resource‐enhancing intervention can serve as an important means to protect public service employees against the deleterious effects of bystander conflict.

Practitioner points

• A resource‐enhancing intervention can protect public service employees against the deleterious effects of bystander conflict.
• Resources related to dealing with a hindering bystander, as well as resources facilitating the continuation of the primary task, are positively associated with employees’ affective well‐being, job dedication, and job performance.

     

Comparisons of children with delayed and normal language at 24 months of age on measures of behavioral difficulties,social and cognitive development

This investigation compared a group of expressive language-delayed children with language-normal children of the same age (M = 25.7 months; SD = 0.8 months) on various measures of development and behavioral difficulties. Data were obtained through language sampling, direct developmental assessment, and maternal reports of children's development and behavior. Scores on measures of social and cognitive development for children with language delay were found to be significantly lower than normals. Further, maternal reports indicated that these children displayed significantly more behavioral difficulties overall than did the language-normal children. Specifically, the language-delayed children exhibited more symptoms of anxiety and depression, withdrawal, sleep problems, and other behavioral disturbances. In addition, children evaluated as expressive language delayed scored significantly lower on measures of receptive language, maternal ratings of communicative competency, and other indices of language proficiency. The results point to the centrality of expressive and receptive language development in relation to early-appearing behavior problems and other developmental milestones. With these findings in mind, early language intervention may not only promote language development, but also prevent the development or exacerbation of socioemotional problems. © 1998 Michigan Association for Infant Mental Health     

Go or no‐go? Developmental improvements in the efficiency of response inhibition in mid‐childhood

This experiment used a modified go/no‐go paradigm to investigate the processes by which response inhibition becomes more efficient during mid‐childhood. The novel task, which measured trials on which a response was initiated but not completed, was sensitive to developmental changes in response inhibition. The effect of inducing time pressure by narrowing allowable response time was also examined. While increasing time pressure did not reduce the inhibitory demands of the task for either age group, older children (aged 9 to 11 years) were able to inhibit their responses at an earlier stage of movement than younger children (aged 5 to 7 years). This shows that as children get older they become more efficient at controlling their behaviour which drives developmental improvements in response inhibition.     

Effects of a prevention program for divorced families on youth cortisol reactivity 15 years later

Objective: We examined whether an empirically based, randomised controlled trial of a preventive intervention for divorced mothers and children had a long-term impact on offspring cortisol regulation.

Design: Divorced mothers and children (age 9–12) were randomly assigned to a literature control condition or the 11-week New Beginnings Program, a family-focused group preventive intervention for mothers and children in newly divorced families.

Main Outcome Measures: Fifteen years after the trial, offspring salivary cortisol (n = 161) was measured before and after a social stress task.

Results: Multilevel mixed models were used to predict cortisol from internalizing symptoms, externalizing symptoms, group assignment and potential moderators of intervention effects. Across the sample, higher externalizing symptoms were associated with lower cortisol reactivity. There was a significant group-by-age interaction such that older offspring in the control group had higher reactivity relative to the intervention group, and younger offspring in the control group exhibited a decline across the task relative to younger offspring in the intervention group.

Conclusions: Preventive interventions for youth from divorced families may have a long-term impact on cortisol reactivity to stress. Results highlight the importance of examining moderators of program effects.     

Evaluating complex interventions: Perspectives and issues for health behaviour change interventions

Objective: Health behaviour change interventions (HBCIs), used in health education, health promotion, patient education and psychotherapy areas, are considered complex interventions. The objective of this article is to discuss the value and limitations of using randomised clinical trials (RCTs) to asses HBCIs.

Methods: A scoping review of the literature was conducted to identify the main challenges of using RCTs for evaluating HBCIs. The issues were illustrated by case studies selected from research conducted by our multidisciplinary team.

Results: In complex interventions, effects are produced not only by the intervention, but are strongly linked to context. Issues relating to transferability of results are therefore critical, and require adjustments to the RCT model. Sampling bias, biases related to the experimental conditions and biases due to the absence of double-blindness were examined and illustrated by case studies.

Conclusion: The results underline the importance of a multidisciplinary approach. They call for adapted or alternative evaluation models that overcome the limitations of RCTs.     

A translational evaluation of renewal of inappropriate mealtime behavior

The term renewal describes the recurrence of previously extinguished behavior that occurs when the intervention context changes. Renewal has important clinical relevance as a paradigm for studying treatment relapse because context changes are necessary for generalization and maintenance of most intervention outcomes. The effects of context changes are particularly important during intervention for pediatric feeding disorders because children eat in a variety of contexts, and extinction is an empirically supported and often necessary intervention. Therefore, we used an ABA arrangement to test for renewal during intervention with 3 children diagnosed with a feeding disorder. The A phase was functional reinforcement of inappropriate mealtime behavior in a simulated home setting with the child's caregiver as feeder, B was function‐based extinction in a standard clinic setting with a therapist as feeder, and the return to the A phase was function‐based extinction in a simulated home setting with caregiver as feeder. Returning to Context A resulted in renewal of inappropriate mealtime behavior across children, despite the caregivers' continued implementation of function‐based extinction with high levels of integrity.     

Cigarette Smoking in Young Adults: Childhood and Adolescent Personality,Familial, and Peer Antecedents

Three models (independent, interdependent, and mediational) were hypothesized in this study, to examine the interrelation of personality, family, and peer determinants and their effects on tobacco use by young adults. Mothers were first interviewed about their children when they were between the ages of 1 and 10 years old. Three subsequent interviews were conducted with the children when they reached adolescence and young adulthood. Results show support for the mediational model. In accordance with family interactional framework conceptions, there was a sequence in patterning: from parenting during early adolescence; to personality and peer factors, extending to smoking in late adolescence; and culminating in smoking in adulthood. With a developmental approach, a number of psychosocial measures were related in both younger and older children. Nevertheless, some interesting developmental differences emerged. The findings suggest at least four possible targets for therapeutic or preventive intervention: the parent, the child, the adolescent, and the peer group.     

Preliminary evidence of the impact of early childhood maltreatment and a preventive intervention on neural patterns of response inhibition in early adolescence

Maltreated youths in foster care often experience negative developmental and psychological outcomes, which have been linked with poor response inhibition. Recent evidence suggests that childhood maltreatment is also associated with alterations in the neural circuitry underlying response inhibition. However, a burgeoning line of research has begun to explore the mitigating effects of preventive interventions on neural functioning. The current study used event‐related functional magnetic resonance imaging to explore the impact of early childhood maltreatment and a preventive intervention on response inhibition in early adolescence. Thirty‐six demographically similar adolescents (ages 9–14 years) completed a Go/NoGo task. The sample included nonmaltreated adolescents (n = 14) and maltreated adolescents who were in foster care as preschoolers and randomly assigned to receive services as usual (n = 11) or a preventive intervention, Multidimensional Treatment Foster Care for Preschoolers (n = 11). The groups demonstrated similar behavioral performance but significantly different neural patterns. The maltreated adolescents who received services as usual demonstrated subcortical hypoactivity during successful response inhibition and subcortical hyperactivity during unsuccessful response inhibition. In contrast, the nonmaltreated adolescents and maltreated adolescents who received the intervention exhibited strikingly similar neural patterns during successful response inhibition, but the maltreated adolescents who received the intervention demonstrated prefrontal hypoactivity during unsuccessful response inhibition. These findings offer preliminary evidence that early childhood maltreatment alters the neural patterns underlying response inhibition in early adolescence and that participating in a preventive intervention could mitigate maltreatment‐related effects on these neural systems.     

汉语婴儿词汇学习的注意偏好

婴儿的动、名词词类学习存在跨文化差异,但是很少研究从注意偏好角度解释这类差异。本研究利用习惯化范式考察汉语婴儿在6-8个月和17-19个月时对事件中人物,动作和物体的区分。结果发现,6-8个月的婴儿仅能区分动作变化,对人物和物体无法区分,而17-19个月的婴儿对三类变化均可以区分。本研究提供了婴儿早期注意偏好发展的实验依据,同时为儿童早期单词获得提供了新的理论基础。     

The Efficacy of Toddler-Parent Psychotherapy for Fostering Cognitive Development in Offspring of Depressed Mothers

The efficacy of Toddler-Parent Psychotherapy (TPP) as a preventive intervention for fostering cognitive development in the offspring of depressed mothers was evaluated. Mothers with major depressive disorder and their toddlers were randomly assigned to TPP (n = 43) or to a nonintervention group (n = 54) and compared to a control group (n = 61) of women with no current or past mental disorder. At baseline (age 20 months), the groups did not differ on the Bayley Mental Development Index. At post-intervention follow-up (age 3 years), a relative decline in IQ was found in the depressed nonintervention group, whereas the depressed intervention and the normal control groups continued to be equivalent, with higher WPPSI-R Full Scale and Verbal IQs. The worst outcome was found among nonintervention children whose mothers had subsequent depressive episodes. The results confirm the developmental risks faced by offspring of depressed mothers and support the efficacy of the preventive intervention in safeguarding successful cognitive development in at-risk youngsters.     

Opening the Black Box: Using Process Evaluation Measures to Assess Implementation and Theory Building

The past decade has seen increasing recognition in prevention science of the need to move away from a black box approach to intervention evaluation and toward an approach that can elaborate on the mechanisms through which changes in the outcomes operate (Chen & Rossi, 1989; Durlak & Wells, 1997; Spoth et al., 1995). An approach that examines issues of program implementation is particularly critical in the design of efficacy studies of school-based preventive interventions. Numerous preventive intervention strategies are now delivered within the schools, often by regular classroom teachers. The extent to which teachers faithfully deliver a particular curriculum or incorporate instructional strategies emphasized by an intervention is a critical question for the overall project evaluation. This article illustrates the utilization of process measures from a multicomponent school-based prevention program to examine implementation of a teaching staff development intervention, and the program's underlying theoretical basis. Given the nested study design, the analyses utilize hierarchical linear models (Bryk & Raudenbush, 1992) to examine changes in teaching strategies by condition and investigate the hypothesized relationships between teaching practices and student behaviors based on the program's theoretical framework. Results suggest that teaching practices in two of the six intervention focus areas were positively impacted in the first 18 months of the project. Findings also support th relationships between teachers' instructional practices and students' behaviour.     

Strengthening socio‐emotional competencies in a school setting: Data from the Pyramid project

Background. Development of socio‐emotional competencies is key to children's successful social interaction at home and at school. Aims. This study examines the efficacy of a UK primary school‐based intervention, the Pyramid project, in strengthening children's socio‐emotional competencies. Sample. Participants were 385 children from seven schools in two UK cities. All children were aged 7–8 years and in school Year 3. Children were screened for socio‐emotional difficulties through the Strengths and Difficulties Questionnaire (SDQ; Goodman, 1997 ) and a multi‐agency meeting of relevant professionals before being allocated to attend a Pyramid Club intervention (n= 103) or a comparison group (n= 282). Method. A 2 × 2 mixed‐model design was used: group (intervention group vs. comparison group) × 2 time points (pre‐ vs. 12 weeks post‐intervention) with repeated measures on the time factor to investigate the impact of the Pyramid Year 3 intervention. Teachers completed the SDQ‐T4‐16 for all children pre‐ and post‐intervention to measure participants’ socio‐emotional health status. Results. As measured by the two SDQ difficulty sub‐scales of Emotional and Peer problems and the SDQ strength sub‐scale of Prosocial behaviour, post‐intervention improvements in the Pyramid attendee group were of greater magnitude than those of the comparison group. Conclusions. The Pyramid project intervention improves the socio‐emotional health of vulnerable children through promoting positive outcomes as well as reducing socio‐emotional deficits. These findings further support the inclusion of a salutogenic approach in promoting children's socio‐emotional well‐being.     

Examining the relationship between word learning, nonword repetition, and immediate serial recall in adults

Two experiments examined whether the association between word-learning, nonword repetition, and immediate serial recall observed in children also exists in normal adults. The experiments also introduce a novel paradigm for studying word-learning. Experiment 1 studied the performance of 52 adults in nonword repetition, immediate serial recall, and word-learning tasks, examining the correlation between these measures. The results indicate that the developmental relationships between all three abilities also exist in adults. Experiment 2 investigated the robustness of these results using different stimuli and a variant of the word-learning task, and it also examined performance in a visuospatial span task, to test an alternative account of the results of Experiment 1; the results from 58 adults provide further evidence that the developmental association between word-learning, nonword repetition, and immediate serial recall extends into adulthood. The theoretical implications of these findings are discussed in terms of alternative models of the relationship between these abilities.