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

Leveraging behavioral genetics methods to accelerate obesity protection discovery: the Augmented T0 Discordant Sibling Design

Researchers have been reimagining strategies to accelerate the pacing of translational science progress so that basic T0 discoveries can be converted more efficiently to T1 to T4 interventions. This is certainly true in the context of childhood obesity prevention given its complex etiology and heterogeneity. Here it is submitted that behavioral genetics methods, which have transformed the understanding of childhood obesity risk, have unrealized potential to accelerate translational science into childhood obesity protection (i.e., maintaining healthy weight status despite the presence of reliable risk factors). To illustrate this opportunity, this Perspective proposes the Augmented T0 Discordant Sibling Design (DSD+ ), which leverages the traditional discordant siblings design by recruiting obesity-discordant siblings specifically from families in which parents have obesity and thereby confer heightened risk. This one modification of a tried-and-true behavior genetics design arguably opens a fascinating door of inquiry, illustrating the broader point. Moreover, as most disorders are familial, the DSD+ may stimulate ideas beyond obesity protection.

Defining and assessing immediacy in single-case experimental designs

Immediacy is one of six data aspects (alongside level, trend, variability, overlap, and consistency) that has to be accounted for when visually analyzing single-case data. Given that it is one of the aspects that has received considerably less attention than other data aspects, the current text offers a review of the proposed conceptual definitions of immediacy (i.e., what it refers to) and also of the suggested operational definitions (i.e., how exactly is it assessed and/or quantified). Provided that a variety of conceptual and operational definitions is identified, we propose following a sensitivity analysis using a randomization test for assessing immediate effects in single-case experimental designs, by identifying when changes were most clear. In such a sensitivity analysis, the immediate effects are tested for multiple possible intervention points and for different possible operational definitions. Robust immediate effects can be detected if the results for the different operational definitions converge.

The Family of Single-Case Experimental Designs

Single-case experimental designs (SCEDs) represent a family of research designs that use experimental methods to study the effects of treatments on outcomes. The fundamental unit of analysis is the single case-which can be an individual, clinic, or community-ideally with replications of effects within and/or between cases. These designs are flexible and cost-effective and can be used for treatment development, translational research, personalized interventions, and the study of rare diseases and disorders. This article provides a broad overview of the family of single-case experimental designs with corresponding examples, including reversal designs, multiple baseline designs, combined multiple baseline/reversal designs, and integration of single-case designs to identify optimal treatments for individuals into larger randomized controlled trials (RCTs). Personalized N-of-1 trials can be considered a subcategory of SCEDs that overlaps with reversal designs. Relevant issues for each type of design-including comparisons of treatments, design issues such as randomization and blinding, standards for designs, and statistical approaches to complement visual inspection of single-case experimental designs-are also discussed.

Valuing the Diversity of Research Methods to Advance Nutrition Science

The ASN Board of Directors appointed the Nutrition Research Task Force to develop a report on scientific methods used in nutrition science to advance discovery, interpretation, and application of knowledge in the field. The genesis of this report was growing concern about the tone of discourse among nutrition professionals and the implications of acrimony on the productive study and translation of nutrition science. Too often, honest differences of opinion are cast as conflicts instead of areas of needed collaboration. Recognition of the value (and limitations) of contributions from well-executed nutrition science derived from the various approaches used in the discipline, as well as appreciation of how their layering will yield the strongest evidence base, will provide a basis for greater productivity and impact. Greater collaborative efforts within the field of nutrition science will require an understanding that each method or approach has a place and function that should be valued and used together to create the nutrition evidence base. Precision nutrition was identified as an important emerging nutrition topic by the preponderance of task force members, and this theme was adopted for the report because it lent itself to integration of many approaches in nutrition science. Although the primary audience for this report is nutrition researchers and other nutrition professionals, a secondary aim is to develop a document useful for the various audiences that translate nutrition research, including journalists, clinicians, and policymakers. The intent is to promote accurate, transparent, verifiable evidence-based communication about nutrition science. This will facilitate reasoned interpretation and application of emerging findings and, thereby, improve understanding and trust in nutrition science and appropriate characterization, development, and adoption of recommendations.

Imagine to Remember: An Episodic Future Thinking Intervention to Improve Medication Adherence in Patients with Type 2 Diabetes

PURPOSE

Medication nonadherence is prevalent in diabetic populations, with "forgetting" a commonly cited reason. This issue of forgetfulness is due, in part, to a failure of prospective memory (PM). Episodic future thinking (EFT) has been shown to improve PM but has not been used to improve medication adherence.

PATIENTS AND METHODS

The current study used a multiple baseline design (N = 4) to test the effects of EFT on medication non-adherence for four patients with a diagnosis of type 2 diabetes or prediabetes, with comorbid high blood pressure or high cholesterol. Medication adherence was objectively measured over 15 weeks using medication event monitoring systems.

RESULTS

Results of visual analysis showed medication adherence was reliably improved, confirmed by mixed model analysis of variance (p < 0.001), with significant differences from baseline to treatment (Tau <0.05) for 3 of 4 participants. Improvements in two measures of PM (effect size (ES) = 0.73, 0.80) and delay discounting (ES = 1.20) were observed.

CONCLUSION

This study provides a feasible way to improve medication adherence in patients with prediabetes or type 2 diabetes.