Sequential Multiple Assignment Randomized Trial (SMART) to identify optimal sequences of telemedicine interventions for improving initiation of insulin therapy: A simulation study

Exercise Strategy for Reducing Visceral Adipose Tissue in Community Residents With Obesity: A Sequential Multiple Assignment Randomized Trial

BACKGROUND

Exercise is the most effective method of reducing visceral adipose tissue (VAT). However, the optimal exercise modality and strategy for reducing VAT have yet to be determined.

PURPOSE

This study was designed to identify the optimal sequence exercise strategy for reducing VAT in community residents with obesity.

METHODS

A sequential multiple assignment randomized trial design was used to conduct a two-stage (8 weeks each) adaptive exercise for 40- to 64-year-old residents with obesity. In the first stage, the participants were randomly allocated into two groups, one of which did 30 minutes of moderate-intensity continuous training (MICT; n = 58) and the other which did 20 minutes of high-intensity interval training (HIIT; n = 58) three times per week. In the second stage, the nonresponders (with VAT decreases < 3%) were randomly reallocated into a group that performed MICT combined with an additional 10 minutes of resistance exercise or one that performed the opposite of the first-stage treatment (HIIT or MICT). Those who responded to the first-stage intervention (with VAT decreases of ≥ 3%) continued the same exercise treatment until 16 weeks.

RESULTS

The MICT intervention was found to be more efficacious than the HIIT intervention in reducing VAT during the first 8 weeks (β = -4.10, p = .029). Among the nonresponders to MICT, the HIIT outperformed MICT combined with resistance exercise as the alternative choice in the second stage (β = -7.36, p = .006). On the contrary, there were no significant differences between MICT and MICT combined with resistance exercise for the nonresponders to HIIT (β = 1.34, p = .626). Those participants who repeated the same exercise modality (either MICT or HIIT) in both stages exhibited superior VAT reduction to those who changed exercise modalities after the first stage.

CONCLUSIONS/IMPLICATIONS FOR PRACTICE

The optimal sequence exercise strategy for reducing VAT is captured by a two-stage sequential multiple assignment randomized trial design. Community residents with obesity are advised to reduce VAT efficiently through participation in an 8-week MICT program. For those preferring HIIT rather than MICT, a 16-week program without changing the modality midway is recommended.

The LvL UP trial: Protocol for a sequential, multiple assignment, randomised controlled trial to assess the effectiveness of a blended mobile lifestyle intervention

BACKGROUND

Blended mobile health (mHealth) interventions - combining self-guided and human support components - could play a major role in preventing non-communicable diseases (NCDs) and common mental disorders (CMDs). This protocol describes a sequential, multiple assignment, randomised trial aimed at (i) evaluating the effectiveness and cost-effectiveness of LvL UP, an mHealth lifestyle intervention for the prevention of NCDs and CMDs, and (ii) establishing the optimal blended approach in LvL UP that balances effective personalised lifestyle support with scalability.

METHODS

LvL UP is a 6-month mHealth holistic intervention targeting physical activity, diet, and emotional regulation. In this trial, young and middle-aged Singaporean adults at risk of developing NCDs or CMDs will be randomly allocated to one of two initial conditions ('LvL UP' or 'comparison'). After 4 weeks, participants categorised as non-responders from the LvL UP group will be re-randomised into second-stage conditions: (i) continuing with the initial intervention (LvL UP) or (ii) additional motivational interviewing (MI) support sessions by trained health coaches (LvL UP + adaptive MI). The primary outcome is mental well-being. Secondary outcomes include anthropometric measurements, resting blood pressure, blood metabolic profile, health status, and health behaviours (physical activity, diet). Outcomes will be measured at baseline, 6 months (post-intervention), and 12 months (follow-up).

DISCUSSION

In addition to evaluating the effectiveness of LvL UP, the proposed study design will contribute to increasing evidence on how to introduce human support in mHealth interventions to maximise their effectiveness while remaining scalable.

TRIAL REGISTRATION

The LvL UP Pilot trial was prospectively registered with ClinicalTrials.gov (NCT06360029).

The Sequential Multiple Assignment Randomized Trial for Controlling Infectious Diseases: A Review of Recent Developments

Infectious diseases have posed severe threats to public health across the world. Effective prevention and control of infectious diseases in the long term requires adapting interventions based on epidemiological evidence. The sequential multiple assignment randomized trial (SMART) is a multistage randomized trial that can provide valid evidence of when and how to adapt interventions for controlling infectious diseases based on evolving epidemiological evidence. We review recent developments in SMARTs to bring wider attention to the potential benefits of employing SMARTs in constructing effective adaptive interventions for controlling infectious diseases and other threats to public health. We discuss 2 example SMARTs for infectious diseases and summarize recent developments in SMARTs from the varied aspects of design, analysis, cost, and ethics. Public health investigators are encouraged to familiarize themselves with the related materials we discuss and collaborate with experts in SMARTs to translate the methodological developments into preeminent public health research. (Am J Public Health. 2023;113(1):49-59. https://doi.org/10.2105/AJPH.2022.307135).

Understanding heterogeneity of responses to, and optimizing clinical efficacy of, exercise training in older adults: NIH NIA Workshop summary

Exercise is a cornerstone of preventive medicine and a promising strategy to intervene on the biology of aging. Variation in the response to exercise is a widely accepted concept that dates back to the 1980s with classic genetic studies identifying sequence variations as modifiers of the VO₂max response to training. Since that time, the literature of exercise response variance has been populated with retrospective analyses of existing datasets that are limited by a lack of statistical power from technical error of the measurements and small sample sizes, as well as diffuse outcomes, very few of which have included older adults. Prospective studies that are appropriately designed to interrogate exercise response variation in key outcomes identified a priori and inclusive of individuals over the age of 70 are long overdue. Understanding the underlying intrinsic (e.g., genetics and epigenetics) and extrinsic (e.g., medication use, diet, chronic disease) factors that determine robust versus poor responses to various exercise factors will be used to improve exercise prescription to target the pillars of aging and optimize the clinical efficacy of exercise training in older adults. This review summarizes the proceedings of the NIA-sponsored workshop entitled, "Understanding Heterogeneity of Responses to, and Optimizing Clinical Efficacy of, Exercise Training in Older Adults" and highlights the importance and current state of exercise response variation research, particularly in older adults, prevailing challenges, and future directions.

A pilot sequential multiple assignment randomized trial (SMART) protocol for developing an adaptive coaching intervention around a mobile application for athletes to improve carbohydrate periodization behavior

Background

It has recently been identified that manipulating carbohydrate availability around exercise activity can enhance training-induced metabolic adaptations. Despite this approach being accepted in the athletic populations, athletes do not systematically follow the guidelines. Digital environments appear to allow nutritionists to deliver this intervention at scale, reducing expensive human coaching time. Yet, digitally delivered dietary behavior change interventions for athletes and the coaching strategy to support them are still novel concepts within sports nutrition.

Methods/design

We aim to recruit 900 athletes across the UK. 500 athletes will be recruited to test the feasibility of a novel menu planner mobile application with coaching for 6 weeks. 250 athletes with pre-existing nutritionist support will also be recruited as control. We will then conduct a 4-week pilot sequential multiple assignment randomized trial (SMART) with an additional 150 athletes. In the SMART, athletes will be given the application and additional coaching according to their engagement responses. The primary outcomes are the mobile application and coach uptake, retention, engagement, and success in attaining carbohydrate periodization behavior. Secondary outcomes are changes in goal, weight, carbohydrate periodization self-efficacy, and beliefs about consequences. Due to the high attrition nature of digital interventions, all quantitative analyses will be carried out based on both the intention-to-treat and per-protocol principles.

Discussion

This study will be the first to investigate improving carbohydrate periodization using a digital approach and tailored coaching strategies under this context. Foundational evidence from this study will provide insights into the feasibility of the digital approach.