Xiaoxi Yan

• Doctor of Philosophy
• Research Fellow at Duke-NUS Medical School

The sequential multiple assignment randomized trial (SMART) is a design used to develop dynamic treatment regimes (DTRs). Given that DTRs are generally less well researched, pilot SMART studies are often necessary. One challenge in pilot SMART is to determine the sample size such that it is small yet meaningfully informative for future full‐fledged...

Background: To examine the value of a Sequential Multiple Assignment Randomized Trial (SMART) design compared to a conventional randomized control trial (RCT) for telemedicine strategies to support titration of insulin therapy for Type 2 Diabetes Mellitus (T2DM) patients new to insulin. Methods: Microsimulation models were created in R using a synt...

Introduction Depression and diabetes are highly disabling diseases with a high prevalence and high rate of comorbidity, particularly in low-income ethnic minority patients. Though comorbidity increases the risk of adverse outcomes and mortality, most clinical interventions target these diseases separately. Increasing physical activity might be effe...

Technological advancements in mobile devices have made it possible to deliver mobile health interventions to individuals. A novel intervention framework that emerges from such advancements is the just-in-time adaptive intervention (JITAI), where it aims to suggest the right support to the individual "just in time", when their needs arise, thus havi...

This review explores the transformative potential of just-in-time adaptive interventions (JITAIs) as a scalable solution for addressing health disparities in underserved populations. JITAIs, delivered via mobile health technologies, could provide context-aware personalized interventions based on real-time data to address public health challenges su...

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 paper describes a sequential, multiple assignment, randomised trial aimed at (i) evaluating the effectiveness and co...

Introduction The multiple risks generated by the COVID-19 pandemic intensified the debate about healthcare access and coverage. Whether the burden of disease caused by the coronavirus outbreak changed public opinion about healthcare provision remains unclear. In this study, it was specifically examined if the pandemic changed support for government...

Technological advancements have made it possible to deliver mobile health interventions to individuals. A novel framework that has emerged from such advancements is the just-in-time adaptive intervention, which aims to suggest the right support to the individuals when their needs arise. The micro-randomized trial design has been proposed recently t...

Sequential multiple assignment randomized trials (SMARTs) are used to construct data-driven optimal intervention strategies for subjects based on their intervention and covariate histories in different branches of health and behavioral sciences where a sequence of interventions is given to a participant. Sequential intervention strategies are often...

Technological advancements have made it possible to deliver mobile health interventions to individuals. A novel framework that has emerged from such advancements is the just-in-time adaptive intervention (JITAI), which aims to suggest the right support to the individuals when their needs arise. The micro-randomized trial (MRT) design has been propo...

Purpose: Here we assess the feasibility of using machine learning models to non-invasively predict muscle glycogen use during exercise. Methods: Two data sets comprised of: 1. Open-source group data from 166 studies, 2. Manually compiled granular data reported at an individual level from 8 studies published subsequently from the first data set matc...

Background: Several intervention strategies have been shown to improve diet quality. However, there is limited evidence on the increase in effectiveness that may be achieved through select combinations of these strategies. Purpose: This study aimed to identify an effective multicomponent intervention to improve diet quality of a grocery basket b...

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...

Background To examine the value of a Sequential Multiple Assignment Randomized Trial (SMART) design compared to a conventional randomized control trial (RCT) for telemedicine strategies to support titration of insulin therapy for Type 2 Diabetes Mellitus (T2DM) patients new to insulin. Methods Microsimulation models were created in R using a synth...

Objective: To determine if rehabilitation uptake and adherence can be increased by providing coordinated transportation (increased convenience) and eliminating out-of-pocket costs (reduced expense). Design: Three-arm randomized controlled trial Setting: Stroke units of two Singapore tertiary hospitals Participants: Singaporeans or permanent residen...

Introduction: While rehabilitation has been demonstrated to be effective in improving outcomes of stroke, uptake of outpatient rehabilitation services (ORS) in Singapore remains relatively low. This study aims to determine if rehabilitation uptake and adherence can be increased by providing coordinated transportation (increased convenience) and eli...

Introduction Depression and diabetes are highly disabling diseases with a high prevalence and high rate of comorbidity, particularly in low-income ethnic minority patients. Though comorbidity increases the risk of adverse outcomes and mortality, most clinical interventions target these diseases separately. Increasing physical activity might be effe...