Illustrating idiographic methods for translation research: moderation effects, natural clinical experiments, and complex treatment-by-subgroup interactions

Power analysis for idiographic (within-subject) clinical trials: Implications for treatments of rare conditions and precision medicine

Power analysis informs a priori planning of behavioral and medical research, including for randomized clinical trials that are nomothetic (i.e., studies designed to infer results to the general population based on interindividual variabilities). Far fewer investigations and resources are available for power analysis of clinical trials that follow an idiographic approach, which emphasizes intraindividual variabilities between baseline (control) phase versus one or more treatment phases. We tested the impact on statistical power to detect treatment outcomes of four idiographic trial design factors that are under researchers' control, assuming a multiple baseline design: sample size, number of observations per participant, proportion of observations in the baseline phase, and competing statistical models (i.e., hierarchical modeling versus piecewise regression). We also tested the impact of four factors that are largely outside of researchers' control: population size, proportion of intraindividual variability due to residual error, treatment effect size, and form of outcomes during the treatment phase (phase jump versus gradual change). Monte Carlo simulations using all combinations of the factors were sampled with replacement from finite populations of 200, 1750, and 3500 participants. Analyses characterized the unique relative impact of each factor individually and all two-factor combinations, holding all others constant. Each factor impacted power, with the greatest impact being from larger treatment effect sizes, followed respectively by more observations per participant, larger samples, less residual variance, and the unexpected improvement in power associated with assigning closer to 50% of observations to the baseline phase. This study's techniques and R package better enable a priori rigorous design of idiographic clinical trials for rare diseases, precision medicine, and other small-sample studies.

Resilience-Informed Community Violence Prevention and Community Organizing Strategies for Implementation: Protocol for a Hybrid Type 1 Implementation-Effectiveness Trial

BACKGROUND

Community violence is a persistent and challenging public health problem. Community violence not only physically affects individuals, but also its effects reverberate to the well-being of families and entire communities. Being exposed to and experiencing violence are adverse community experiences that affect the well-being and health trajectories of both children and adults. In the United States, community violence has historically been addressed through a lens of law enforcement and policing; the impact of this approach on communities has been detrimental and often ignores the strengths and experiences of community members. As such, community-centered approaches to address violence are needed, yet the process to design, implement, and evaluate these approaches is complex. Alternatives to policing responses are increasingly being implemented. However, evidence and implementation guidance for community-level public health approaches remain limited. This study protocol seeks to address community violence through a resilience framework-Adverse Community Experiences and Resilience (ACE|R)-being implemented in a major US city and leveraging a strategy of community organizing to advance community violence prevention.

OBJECTIVE

The objective of this research is to understand the impact of community-level violence prevention interventions. Furthermore, we aim to describe the strategies of implementation and identify barriers to and facilitators of the approach.

METHODS

This study uses a hybrid type 1 effectiveness-implementation design. Part 1 of the study will assess the effectiveness of the ACE|R framework plus community organizing by measuring impacts on violence- and health-related outcomes. To do so, we plan to collect quantitative data on homicides, fatal and nonfatal shootings, hospital visits due to nonaccidental injuries, calls for service, and other violence-related data. In Part 2 of the study, to assess the implementation of ACE|R plus community organizing, we will collect process data on community engagement events, deliver community trainings on community leadership and organizing, and conduct focus groups with key partners about violence and violence prevention programs in Milwaukee.

RESULTS

This project received funding on September 1, 2020. Prospective study data collection began in the fall of 2021 and will continue through the end of 2023. Data analysis is currently underway, and the first results are expected to be submitted for publication in 2024.

CONCLUSIONS

Community violence is a public health problem in need of community-centered solutions. Interventions that center community and leverage community organizing show promise in decreasing violence and increasing the well-being of community members. Methods to identify the impact of community-level interventions continue to evolve. Analysis of outcomes beyond violence-specific outcomes, including norms and community beliefs, may help better inform the short-term and proximal impacts of these community-driven approaches. Furthermore, hybrid implementation-effectiveness trials allow for the inevitable contextualization required to disseminate community interventions where communities drive the adaptations and decision-making.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/50444.

Single case designs for early phase behavioral translational research in health psychology

OBJECTIVE

The biomedical research community has long recognized that much of the basic research being conducted, whether in the biological, behavioral or social sciences, is not readily translated into clinical and public health applications. This translational gap is due in part to challenges inherent in moving research findings from basic or discovery research to applied research that addresses clinical or public health problems. In the behavioral and social sciences, research designs typically used in the early phases of translational research are small, underpowered "pilot" studies that may lack sufficient statistical power to test the research question of interest. While this approach is discouraged, these studies are often employed to estimate effect sizes before embarking on a larger trial with adequate statistical power to test the research hypothesis. The goal of this paper is to provide an alternative approach to early phase studies using single case designs (SCDs).

METHOD

Review basic principles of SCDs; provide a series of hypothetical SCD replication experiments to illustrate (1) how data from SCDs can be analyzed to test the effects of an intervention on behavioral and biological outcomes and (2) how sample sizes can be derived for larger randomized controlled trials (RCTs) based on clinically meaningful effects from SCDs; and review feedback between SCDs and RCTs.

RESULTS

The paper illustrates the use of SCD reversal and multiple baseline designs for early phase translational research.

CONCLUSION

SCDs provide a flexible and efficient platform for the use of experimental methods in early phase translational research. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

A complex dynamical systems approach to the development of feeding problems in early childhood

Though it is commonly agreed upon that the development of feeding problems in early childhood is a complex process, much of the research on these problems has a component-oriented focus, and very little attention is paid to the mechanisms that lead to these kinds of problems in individual children. The aim of this theoretical paper is to interpret the development of feeding problems in early childhood from a complex dynamical systems viewpoint. In addition to its focus on self-organization and nonlinearity, this approach defines several central properties of development: soft-assembly, embodiment, iterativity, the emergence of higher-order properties, and intra-individual variability. In this paper, I argue that each of these properties is highly relevant for understanding feeding problems and discuss the implications of this for both clinical practice and research purposes.

Effects of Behavioral Treatment Modified to Fit Children with Conduct Problems and Callous-Unemotional (CU) Traits

Research suggests that children with conduct problems (CP) and callous-unemotional (CU) traits show a diminished response to behavior therapy, perhaps due to a reward-oriented, punishment insensitive learning style. Children with CP and CU may benefit from personalizing behavioral treatment for them by emphasizing rewards and de-emphasizing punishments. This hypothesis was tested in a sample of 46 children (78.3% boys), ages 7.0 to 12.6 years (M = 9.3, SD = 1.4). All participants met criteria for ODD and ADHD and 63% also met criteria for CD. Participants were oversampled for high CU, but CU scores ranged from average to high. Children received four weeks of modified behavior therapy that emphasized rewards and de-emphasized punishments and four weeks of treatment as usual, which was standard behavior therapy that balanced rewards and punishments. Treatments were implemented in a summer treatment program and compared using a within-subjects design, with order of treatment counterbalanced. Disruptive behavior was equal or slightly higher in modified behavior therapy than in standard behavior therapy on point system measures, but lower on parent weekly ratings. End of treatment ratings showed both treatments produced significant improvements compared to pre-treatment ratings but did not differ from each other. Personalizing behavior therapy for children with CP and CU produced inconsistent findings relative to standard behavior therapy. Behavior therapy is likely to be a necessary part of treatment for children with CP and CU, but treatment personalization efforts may provide some benefit by addressing other deficits shown by these children.

Positive Health Check evaluation: A type 1 hybrid design randomized trial to decrease HIV viral loads in patients seen in HIV primary care

For people with HIV, important transmission prevention strategies include early initiation and adherence to antiretroviral therapy and retention in clinical care with the goal of reducing viral loads as quickly as possible. Consequently, at this point in the HIV epidemic, innovative and effective strategies are urgently needed to engage and retain people in health care to support medication adherence. To address this gap, the Positive Health Check Evaluation Trial uses a type 1 hybrid randomized trial design to test whether the use of a highly tailored video doctor intervention will reduce HIV viral load and retain people with HIV in health care. Eligible and consenting patients from four HIV primary care clinical sites are randomly assigned to receive either the Positive Health Check intervention in addition to the standard of care or the standard of care only. The primary aim is to determine the effectiveness of the intervention. A second aim is to understand the implementation potential of the intervention in clinic workflows, and a third aim is to assess the costs of intervention implementation. The trial findings will have important real-world applicability for understanding how digital interventions that take the form of video doctors can be used to decrease viral load and to support retention in care among diverse patients attending HIV primary care clinics.

Scientific challenges for precision public health

The notion of ‘precision’ public health has been the subject of much debate, with recent articles coming to its defence following the publication of several papers questioning its value.

Critics of precision public health raise the following problems and questionable assumptions: the inherent limits of prediction for individuals; the limits of approaches to prevention that rely on individual agency, in particular the potential for these approaches to widen inequalities; the undue emphasis on the supposed new information contained in individuals’ molecules and their ‘big data’ at the expense of their own preferences for a particular intervention strategy and the diversion of resources and attention from the social determinants of health.

In order to refocus some of these criticisms of precision public health as scientific questions, this article outlines some of the challenges when defining risk for individuals; the limitations of current theory and study design for precision public health; and the potential for unintended harms.

Innovative Research Methods to Advance Precision in Home Visiting for More Efficient and Effective Programs

Home visiting during early childhood can improve a range of outcomes for children and families. As evidence-based models are implemented across the nation, two questions have emerged. First, can home visiting improve outcomes more efficiently? Second, can overall effects be strengthened for specific subgroups of families? For the past several decades, research focused on testing the average effects of home visiting models on short- to long-term outcomes has found small impacts. These effects are not the same for all families. The field needs new evidence produced in new ways to overcome these challenges. In this article, we provide an overview of the evidence in this field, including what works and for whom. Next, we explain precision approaches to various fields and how this approach could be used in home visiting programs. Research on precision home visiting focuses on the ingredients of home visiting models, collaborating with practitioners to identify the ingredients and testing them on near-term outcomes, and using innovative study designs to learn more quickly what works best for which families. We conclude by proposing four pillars of research that will help achieve precision home visiting services.

Randomized controlled trial of emotionally focused couple therapy compared to treatment as usual for depression: Outcomes and mechanisms of change

This randomized controlled trial examined the effectiveness of Emotionally Focused Therapy (EFT) for depression and relationship satisfaction versus usual care (i.e., couple therapy other than EFT), and explored mechanisms of change. Mixed model trajectory analyses of 16 couples indicated EFT was associated with greater improvement in relationship satisfaction among men and women. Men receiving EFT reported greater improvements in depressive symptoms compared to usual care. Unified structural equation modeling revealed changes in relationship satisfaction preceded changes in depressive symptoms in one cluster of partners, while changes in depression preceded changes in relationship satisfaction in a second cluster. Two other clusters reported simultaneous changes in satisfaction and depression. This study provides encouraging results on the effectiveness of EFT for depression, and insight into mechanisms of change.

The Clinical Trials Mosaic: Toward a Range of Clinical Trials Designs to Optimize Evidence-Based Treatment

OBJECTIVE

Dichotomizing clinical trials designs into nomothetic (e.g., randomized clinical trials or RCTs) versus idiographic (e.g., N-of-1 or case studies) precludes use of an array of hybrid designs and potential research questions between these extremes. This paper describes unique clinical evidence that can be garnered using idiographic clinical trials (ICTs) to complement RCT data. Proposed and illustrated herein is that innovative combinations of design features from RCTs and ICTs could provide clinicians with far more comprehensive information for testing treatments, conducting pragmatic trials, and making evidence-based clinical decisions.

METHOD

Mixed model trajectory analysis and unified structural equations modeling were coupled with multiple baseline designs in (a) a true N-of-1 pilot study to improve severe autism-related communication deficits and (b) a small sample preliminary study of two complimentary interventions to relieve wheelchair discomfort.

RESULTS

Evidence supported certain mechanisms of treatment outcomes and ruled out others. Effect sizes included mean phase differences (i.e., effectiveness), trajectory slopes, and differences in path coefficients between study phases.

CONCLUSIONS

ICTs can be analyzed with equivalent rigor as, and generate effect sizes comparable to, RCTs for the purpose of developing hybrid designs to augment RCTs for pilot testing innovative treatment, efficacy research on rare diseases or other small populations, quantifying within-person processes, and conducting clinical trials in many situations when RCTs are not feasible.

Biometrics and Policing: A Protocol for Multichannel Sensor Data Collection and Exploratory Analysis of Contextualized Psychophysiological Response During Law Enforcement Operations

Background

Stress experienced by law enforcement officers is often extreme and is in many ways unique among professions. Although past research on officer stress is informative, it is limited, and most studies measure stress using self-report questionnaires or observational studies that have limited generalizability. We know of no research studies that have attempted to track direct physiological stress responses in high fidelity, especially within an operational police setting. The outcome of this project will have an impact on both practitioners and policing researchers. To do so, we will establish a capacity to obtain complex, multisensor data; process complex datasets; and establish the methods needed to conduct idiopathic clinical trials on behavioral interventions in similar contexts.

Objective

The objective of this pilot study is to demonstrate the practicality and utility of wrist-worn biometric sensor-based research in a law enforcement agency.

Methods

We will use nonprobability convenience-based sampling to recruit 2-3 participants from the police department in Durham, North Carolina, USA.

Results

Data collection was conducted in 2016. We will analyze data in early 2017 and disseminate our results via peer reviewed publications in late 2017.

Conclusions

We developed the Biometrics & Policing Demonstration project to provide a proof of concept on collecting biometric data in a law enforcement setting. This effort will enable us to (1) address the regulatory approvals needed to collect data, including human participant considerations, (2) demonstrate the ability to use biometric tracking technology in a policing setting, (3) link biometric data to law enforcement data, and (4) explore project results for law enforcement policy and training.

A Case Study Examining Fixed Versus Randomized Criteria for Treating a Child With Conduct Problems and Callous-Unemotional Traits

Children with conduct problems and callous unemotional traits (CPCU) seem to show a decreased response to behavioral treatment (Hawes, Price, & Dadds, 2014). It was hypothesized that children with CPCU may respond differently to behavior therapy when the target behavior criteria are fixed a priori versus when the target behavior criteria are randomly determined post hoc. A single-case study experiment was conducted as an initial step toward investigating this hypothesis. The study was conducted using a daily report card implemented in the context of an intensive behavioral summer treatment program. Results indicated that rates of negative behaviors were higher when rewards were delivered using randomly determined levels of target behaviors as compared to using fixed levels of target behaviors. Results suggest the importance of providing children with CPCU specific and predictable treatment goals when using contingency management procedures. Additional research that examines how children with CPCU react to components of behavioral treatment may help improve their response to behavior therapy.

The full translational spectrum of prevention science: facilitating the transfer of knowledge to practices and policies that prevent behavioral health problems

A broad-span, six-stage translational prevention model is presented, extending from the basic sciences-taking a multi-level systems approach, including the neurobiological sciences-through to globalization. The application of a very wide perspective of translation research from basic scientific discovery to international policy change promises to elicit sustainable, population-level reductions in behavioral health disorders. To illustrate the conceptualization and actualization of a program of translational prevention research, we walk through each stage of research to practice and policy using an exemplar, callous-unemotional (CU) traits. Basic science has identified neurobiological, psychophysiological, behavioral, contextual, and experiential differences in this subgroup, and yet, these findings have not been applied to the development of more targeted intervention. As a result, there are currently no programs considered especially effective for CU traits, likely because they do not specifically target underlying mechanisms. To prevent/reduce the prevalence of conduct disorder, it is critical that we transfer existing knowledge to subsequent translational stages, including intervention development, implementation, and scaling. And eventually, once resulting programs have been rigorously evaluated, replicated, and adapted across cultural, ethnic, and gender groups, there is potential to institutionalize them as well as call attention to the special needs of this population. In this paper, we begin to consider what resources and changes in research perspectives are needed to move along this translational spectrum.