Amutha Ramadas

Background: Childhood diarrhoeal disease remains a leading cause of child mortality worldwide. Although predictive models have been increasingly proposed for early warning, their methodological quality and validation have not been systematically appraised using formal risk of bias frameworks. This systematic review aimed to identify, describe, and critically appraise individual-level prediction models and population-level forecasting studies for childhood diarrhoeal outcomes, focusing on model development, validation, reporting quality, and operational readiness. Methods: Following PRISMA 2020 guidelines (PROSPERO: CRD420251232269), we searched seven databases and grey literature sources from January 2000 to September 18, 2025. We included studies that developed or validated multivariable prediction models for diarrhoeal outcomes in children, including statistical, machine learning, and hybrid approaches. Individual-level models were assessed using the Prediction Model Risk of Bias Assessment Tool (PROBAST), and population-level studies were appraised qualitatively for methodological credibility, with emphasis on validation. Results: From the 20,662 records screened, 38 studies met the inclusion criteria. Publications accelerated after 2020, with 78.9% of included studies published in this period. The evidence base comprised 25 single-country studies and 13 multi-country or global analyses. Statistical models were most commonly used, as reported in 18 studies, while ensemble or hybrid approaches such as hybrid statistical–machine learning models were applied in 11 studies, and machine learning methods in eight studies. Predictor selection varied widely, with socio-demographic and household factors included in 23 studies and environmental or climatic variables in 18. Among the 15 individual-level prediction models assessed using PROBAST, five showed high overall risk of bias. Of the 19 population-level forecasting studies appraised qualitatively, only three undertook rigorous out-of-sample temporal validation. The remaining four studies were classified as other modelling categories and were summarised descriptively. Conclusions: Research on childhood diarrhoeal prediction has expanded rapidly across individual-level, population-level, and related classification models. Although some studies reported stronger validation practices, these remained uncommon, leaving evidence for transportability and implementation readiness limited for most models. Future progress will depend on closer alignment between modelling objective, validation strategy, appraisal framework, and transparent reporting.

Background: Malaysia is a multicultural country with the main ethnic groups being Malays, Chinese, and Indians. This diversity creates a rich food culture with distinct dishes, cooking styles, and portion sizes, making dietary assessment challenging. Intake24 is a web-based 24-hour dietary recall (24hDR) system that automates data collection, reduces recall bias, and saves time. It supports self-reporting of the previous day’s food and beverage intake using structured prompts, searchable food lists, portion-size images, and linked food composition data. As it was originally developed in the United Kingdom, adaptation for Malaysia is needed to address differences in language, food culture, mixed dishes, portion sizes, terminology, and local food composition data. Objective: This paper aims to describe a protocol for the development and relative validation of Intake24 Malaysia (Intake24-MY) for the Malaysian population. Methods: This paper describes 2 phases in adapting Intake24-MY: (1) the development process and (2) the validation study. Phase 1 consists of the following components: (1a) system translation, which will involve machine translation tools and bilingual translators; (1b) food list development, which includes Malaysian and globally familiar foods; (1c) 4 options for portion-size estimation and a photograph validation study; (1d) food composition data and recipe calculation; (1e) small-scale testing, which will involve 10 adults identifying the foods and technical issues, with pilot testing conducted among 100 adults to compare 2 days of dietary intake using Intake24-MY against an interviewer-led 24hDR; and (1f) user guide development. Phase 2 consists of the following components: (2a) a single-meal validation study that will be conducted among 100 adults, comparing Intake24-MY with observed intake and (2b) a cross-sectional study that will be conducted among 482 Malaysian adults, comparing 4 days of dietary intake using Intake24-MY against an interviewer-led 24hDR. A structured questionnaire will be used to assess the feedback on the usability of Intake24-MY. The Bland-Altman method will be used to determine the agreement between these methods. Results: The study was funded in December 2023, with data collection starting in June 2024 and continuing. Data analysis is set to begin in August 2026, with results expected by 2027. This study has received approval from the Monash University Human Research Ethics Committee (MUHREC ID 41337). Conclusions: Intake24-MY is being developed as a multilingual digital dietary assessment tool for Malaysia. The planned validation study will determine its agreement with interviewer-led 24hDRs and assess its usability among Malaysian adults. If shown to be valid and acceptable, Intake24-MY can support more efficient dietary data collection in Malaysia’s multicultural population.

Background: Obesity is a growing concern among young Malaysian adults, increasing the risk of chronic diseases. This study investigates the dietary and lifestyle risk factors of overweight/obesity (OW/OB) and explores the motivations and barriers to healthy change among individuals with OW/OB. Methods: A sequential explanatory mixed-methods design was used. Phase 1 consisted of a cross-sectional survey of 280 university students (aged 18–25 years) that assessed their diet, eating behaviours, screen time, physical activity, sleep, psychosocial factors, and self-reported anthropometric measures. Multivariable logistic regression identified lifestyle and dietary predictors of OW/OB. In Phase 2, purposive sampling was used to invite 20 participants with OW/OB to four online focus group discussions guided by the Health Belief Model (HBM). Thematic analysis was conducted using NVivo, and integration occurred through a mixed-methods joint display. Results: Multivariate logistic regression of Phase 1 data showed that higher cognitive restraint (AOR = 1.02, 95% CI = 1.01–1.04) and screen time (AOR = 1.05, 95% CI = 1.01–1.10) were positively associated with OW/OB, while vegetable intake was protective (AOR = 0.80, 95% CI = 0.68–0.95). Qualitative findings revealed key mechanisms underpinning these associations: cravings and restrictive eating cycles, cost and time barriers to healthy eating, digital-driven cues for sedentary snacking, and heightened perceived susceptibility to future illness. Integration of findings showed that although young adults recognise the severity of obesity, structural and psychosocial barriers often outweigh intentions to adopt healthier behaviours. Conclusion: The risk of obesity among Malaysian young adults is shaped by the interaction of dietary habits, digital lifestyles, and behavioural mechanisms linked to the HBM. Effective interventions must extend beyond education to address the affordability of healthy food, manage screen-related behavioural cues, and enhance coping strategies for stress and cravings. This study provides deeper insight into modifiable pathways and supports the design of targeted obesity prevention strategies for Malaysian youth.

Background: Mobile phone ecological momentary assessment (EMA) methods are a well-established measure of eating and drinking behaviors, but compliance can be poor. Micro-EMA (μEMA), which collects information with a single tap response to brief questions on smartwatches, offers a novel application that may improve response rates. To our knowledge, there is no data evaluating μEMA to measure eating habits in children or in low-to-middle-income countries. Objective: In this study, we investigated the feasibility of micro-EMA to measure eating patterns in Malaysian children and adolescents. Methods: We invited 100 children and adolescents aged 7-18 years in Segamat, Malaysia, to participate in 2021-2022. Smartwatches were distributed to 83 children and adolescents who agreed to participate. Participants were asked to wear the smartwatch for 8 days and respond to 12 prompts per day, hourly, from 9AM to 8PM, asking for information on their meals, snacks, and drinks consumed. A questionnaire captured their experiences using the smartwatch and μEMA interface. Response rate (proportion of prompts responded to) assessed participants’ adherence. We explored associations between response rate with time of day, across days, age, and sex using multilevel binomial logistic regression modeling. Results: Eighty-two participants provided usable smartwatch data. The median number (IQR) of meals, drinks, and snacks per day was 2 (2-4), 3 (1-5), and 1 (0-2), respectively, on the first day of the study. The median response rate across the study was 68% (IQR 50-83). The response rate decreased across study days from 74% (68-78) on Day 1 to 40% (30-50) on Day 7 (odds ratio [OR] per study day 0.73, 95% CI 0.64-0.83). Response rate was lowest at the start of the day and highest between the hours of 12 PM and 2 PM. Female participants responded to more prompts than male participants (OR 1.72, 95% CI 1.03-2.86). There was no evidence of differential response by age (OR 0.73, 95% CI 0.41-1.28). Most participants (65%) rated their experience using the smartwatch positively, with 33% saying they were happy to participate in future studies using the smartwatch. For children that did not wear the smartwatch for the full study duration (n=22), discomfort was the most common complaint (41%). Conclusions: In this study of the feasibility of μEMA on smartwatches to measure eating in Malaysian children, we found the method was acceptable. However, response rates declined across study days, resulting in substantial missingness. Future studies (eg, through focus groups) should explore approaches to improving response to event prompts, trial alternative devices to increase children’s comfort, and evaluate revised protocols for reporting of intake events.

Background: Low-income populations in Malaysia face significant barriers to cardiovascular disease (CVD) prevention, including limited access to health information, preventive services, and ongoing support for behavior change. Digital health technologies present scalable opportunities for promoting heart-healthy behaviors, especially when integrated with community-based peer support. Objective: This study aimed to describe the development and process evaluation of MYCardio-PEER (Peer-led digital health lifestyle intervention for CVD prevention in a low-income Malaysian community), designed to empower adults at risk for CVD through mobile technology and community-based peer engagement. Methods: MYCardio-PEER was developed using the Medical Research Council Framework for Developing and Evaluating Complex Interventions, which included evidence synthesis, theory application, intervention planning, and content design. A 2-round Delphi method was used to conduct content validation involving 10 experts and community panel members, assessing relevance, clarity, and cultural appropriateness. The final intervention was delivered over 8 weeks and included bite-sized educational videos and infographics, and peer-led interactive activities. A pre-post feasibility trial was conducted in Kulim, Kedah, with 30 adults identified as having moderate to high CVD risk. Outcome measures included anthropometric and clinical parameters, dietary intake, and physical activity. A process evaluation assessed participant adherence and program satisfaction, and correlations with health outcomes. Results: Participants (18/30, 60.0% male, mean age 58.2, SD 6.7 years) showed significant reductions in CVD risk score, systolic blood pressure, total cholesterol, and low-density lipoprotein cholesterol. Physical activity levels and selected dietary behaviors improved post intervention. Program adherence was high, with 82.4% of participants completing all peer-led sessions. Satisfaction with program content (85.7%) and peer leadership (96.0%) was strong. Participants described the content as accessible, engaging, and relevant to their daily lives. Conclusions: MYCardio-PEER was developed and content-validated as a peer-led digital health lifestyle intervention for a low-income community at risk of CVD. Process evaluation showed good feasibility and acceptability, with encouraging pre-post improvements in behaviors and selected health indicators. These findings suggest the potential of integrating peer support with culturally adapted digital content in community-based CVD prevention. Trial Registration: ClinicalTrials.gov NCT06408493; http://clinicaltrials.gov/study/NCT06408493 International Registered Report Identifier (IRRID): RR2-10.1017/S1463423625000192

Background Mobile-phone ecological momentary assessment (EMA) methods are a well-established measure of eating and drinking behaviours, but compliance can be poor. Micro-EMA (μEMA), which collects information with single tap response to brief questions on smartwatches, offers a novel application that may improve response rates. To our knowledge, there is no data evaluating μEMA to measure eating habits in children or in low-to-middle income countries. Objective We investigated the feasibility of micro-EMA to measure eating patterns in Malaysian children and adolescents. Methods We invited 100 children and adolescents aged 7-18 in Segamat, Malaysia to participate in 2021-2022. Smartwatches were distributed to 83 children and adolescents who agreed to participate. Participants were asked to wear the smartwatch for 8 days and respond to 12 prompts hourly from 8am to 8pm, asking for information on their meals, snacks and drinks consumed. A questionnaire captured their experiences using the smartwatch and μEMA interface. Response rate (proportion of prompts responded to) assessed participants’ adherence. We explored associations between response rate with time of day, across days, age and sex using multi-level binomial logistic regression modelling. Results Eighty-two participants provided usable smartwatch data. The median number (inter-quartile range) of meals, drinks and snacks per day were 2 (2 - 4), 3 (1 - 5) and 1 (0 - 2) respectively on the first day of the study. The median response rate across the study was 68% (quartiles: [50, 83]). The response rate decreased across study days from 74% (68, 78) on day 1 to 40% (30, 50) on day 7 (odds ratio [OR] per study day: 0.73 [95% confidence interval [CI]: 0.64, 0.83]). Response rate was lowest at the start of the day, and highest between the hours of 12:00-14:00. Female participants responded to more prompts than male participants (OR: 1.72 95% CI: [1.03, 2.86). There was no evidence of differential response by age (OR: 0.73 95% CI: [0.41, 1.28]). Most participants (65%) rated their experience using the smartwatch positively, with 33% saying they were happy to participate in future studies using the smartwatch. For children that didn’t wear the smartwatch for the full study duration (n=22), discomfort was the most common complaint (41%). Conclusions In this study of the feasibility of μEMA on smartwatches to measure eating in Malaysian children we found the method was acceptable. However, response rates declined across study days resulting in substantial missingness. Future studies (e.g. through focus groups) should explore approaches to improving response to event prompts, trial alternative devices to increase children’s comfort and evaluate revised protocols for reporting of intake events.

BACKGROUND Low-income populations in Malaysia face significant barriers to cardiovascular disease (CVD) prevention, including limited access to health information, preventive services, and ongoing support for behavior change. Digital health technologies present scalable opportunities for promoting heart-healthy behaviors, especially when integrated with community-based peer support. OBJECTIVE This study aimed to describe the development and process evaluation of MYCardio-PEER (Peer-led digital health lifestyle intervention for CVD prevention in a low-income Malaysian community), designed to empower adults at risk for CVD through mobile technology and community-based peer engagement. METHODS MYCardio-PEER was developed using the Medical Research Council Framework for Developing and Evaluating Complex Interventions, which included evidence synthesis, theory application, intervention planning, and content design. A 2-round Delphi method was used to conduct content validation involving 10 experts and community panel members, assessing relevance, clarity, and cultural appropriateness. The final intervention was delivered over 8 weeks and included bite-sized educational videos and infographics, and peer-led interactive activities. A pre-post feasibility trial was conducted in Kulim, Kedah, with 30 adults identified as having moderate to high CVD risk. Outcome measures included anthropometric and clinical parameters, dietary intake, and physical activity. A process evaluation assessed participant adherence and program satisfaction, and correlations with health outcomes. RESULTS Participants (18/30, 60.0% male, mean age 58.2, SD 6.7 years) showed significant reductions in CVD risk score, systolic blood pressure, total cholesterol, and low-density lipoprotein cholesterol. Physical activity levels and selected dietary behaviors improved post intervention. Program adherence was high, with 82.4% of participants completing all peer-led sessions. Satisfaction with program content (85.7%) and peer leadership (96.0%) was strong. Participants described the content as accessible, engaging, and relevant to their daily lives. CONCLUSIONS MYCardio-PEER was developed and content-validated as a peer-led digital health lifestyle intervention for a low-income community at risk of CVD. Process evaluation showed good feasibility and acceptability, with encouraging pre-post improvements in behaviors and selected health indicators. These findings suggest the potential of integrating peer support with culturally adapted digital content in community-based CVD prevention. CLINICALTRIAL ClinicalTrials.gov NCT06408493; http://clinicaltrials.gov/study/NCT06408493 INTERNATIONAL REGISTERED REPORT RR2-10.1017/S1463423625000192

BACKGROUND Mobile phone ecological momentary assessment (EMA) methods are a well-established measure of eating and drinking behaviors, but compliance can be poor. Micro-EMA (μEMA), which collects information with a single tap response to brief questions on smartwatches, offers a novel application that may improve response rates. To our knowledge, there is no data evaluating μEMA to measure eating habits in children or in low-to-middle-income countries. OBJECTIVE In this study, we investigated the feasibility of micro-EMA to measure eating patterns in Malaysian children and adolescents. METHODS We invited 100 children and adolescents aged 7-18 years in Segamat, Malaysia, to participate in 2021-2022. Smartwatches were distributed to 83 children and adolescents who agreed to participate. Participants were asked to wear the smartwatch for 8 days and respond to 12 prompts per day, hourly, from 9AM to 8PM, asking for information on their meals, snacks, and drinks consumed. A questionnaire captured their experiences using the smartwatch and μEMA interface. Response rate (proportion of prompts responded to) assessed participants’ adherence. We explored associations between response rate with time of day, across days, age, and sex using multilevel binomial logistic regression modeling. RESULTS Eighty-two participants provided usable smartwatch data. The median number (IQR) of meals, drinks, and snacks per day was 2 (2-4), 3 (1-5), and 1 (0-2), respectively, on the first day of the study. The median response rate across the study was 68% (IQR 50-83). The response rate decreased across study days from 74% (68-78) on Day 1 to 40% (30-50) on Day 7 (odds ratio [OR] per study day 0.73, 95% CI 0.64-0.83). Response rate was lowest at the start of the day and highest between the hours of 12 PM and 2 PM. Female participants responded to more prompts than male participants (OR 1.72, 95% CI 1.03-2.86). There was no evidence of differential response by age (OR 0.73, 95% CI 0.41-1.28). Most participants (65%) rated their experience using the smartwatch positively, with 33% saying they were happy to participate in future studies using the smartwatch. For children that did not wear the smartwatch for the full study duration (n=22), discomfort was the most common complaint (41%). CONCLUSIONS In this study of the feasibility of μEMA on smartwatches to measure eating in Malaysian children, we found the method was acceptable. However, response rates declined across study days, resulting in substantial missingness. Future studies (eg, through focus groups) should explore approaches to improving response to event prompts, trial alternative devices to increase children’s comfort, and evaluate revised protocols for reporting of intake events.