The BRAVE (Behaviourally Responsive Assessments of Vital Signs in Emergency) Study

1.0 WHAT IS THE PROBLEM TO BE ADDRESSED? Children with Autism Spectrum Disorder (ASD) are significantly overrepresented in Emergency Department (ED) visits, with higher rates of behavioural crises, sensory dysregulation, and unmet medical needs compared to their neurotypical peers.3,4 These children often encounter environments with bright lights, loud noises, unpredictable routines, and unfamiliar staff which can exacerbate distress, complicate assessment, and prolong care.5 Routine vital sign collection is frequently incomplete and a source of distress in autistic patients. 6 Routine collection instruments such as fingertip pulse oximeters and contact thermometers require repeated touch by unfamiliar providers, often in an overstimulating triage room. 7,8 For autistic patients with sensory or communication challenges, these situations may cause distress and escalate to repeated vital sign attempts, delayed decision-making, physical or chemical restraints, interventions with known physical and emotional risks, and moral distress for the patients, families, and healthcare providers involved.9 While sensory toolkits or environmental adaptations can help reduce discomfort, they do not solve the problem of standard vital sign machines capturing limited or unreliable data that is crucial for patient care, when collected during a time of exacerbated distress.5 Wearable biometric monitoring devices such as the Masimo Radius PPG and Radius T offer a promising alternative. This device is being utilized at Dartmouth General Hospital in Nova Scotia to better manage ED wait times and continuously monitor high-risk patients, but no hospital has assessed the benefits it may have on supporting pediatric patients with ASD.30 These devices use a lightweight adhesive sensor that can be applied quickly with the support of caregivers anywhere in the ED. Once applied, they wirelessly measure heart rate (HR), respiratory rate (RR), peripheral oxygen saturation (SpO2) and temperature (T), allowing the child and caregiver to move to a quieter, less stimulating environment while accurate vitals are collected. This could reduce distress for the patient and their caregiver(s), improve vital sign data collection, and support trauma-informed, neuro-affirming care. 10,11,12,13,14 Independent studies have demonstrated Radius PPG utility for continuous monitoring in perioperative, acute, and chronic care contexts, however their feasibility and acceptability in a high-acuity pediatric ED setting, particularly for autistic children, remain untested.

1.1 WHAT ARE THE RESEARCH QUESTION(S) TO BE ADDRESSED?

Among autistic children aged 2-17 years presenting to the ED, does the combined use of Masimo Radius PPG and Radius T wearable monitors reduce the time required to obtain HR, RR, SpO2 and T by at least 20% compared to standard methods, without increasing distress levels, as measured by two objective, validated, behavioural scales revised Faces, Legs, Activity, Cry, Consolability (r-FLACC) and Children's Fear Scale (CFS). Before we can answer this question, several uncertainties remain regarding feasibility, tolerance, and data completeness. To address these gaps, we propose a pilot feasibility trial with the following aims:

Primary aim: To determine the feasibility of conducting a definitive multicentre randomized controlled trial comparing wearable monitoring with standard-of-care vital-sign monitoring in autistic children presenting to a pediatric emergency department. Primary trial feasibility will be assessed using participant retention, protocol adherence, and completeness of required study data.

Primary hypothesis:

A definitive multicentre trial will be considered feasible if the prespecified Green RAG progression thresholds are met for participant retention, protocol adherence, and completeness of required study data, with each primary trial-feasibility outcome reaching at least 80% and with no safety concern requiring study discontinuation.

Secondary intervention-feasibility aim: To describe the feasibility of delivering each allocated monitoring approach, including successful initiation of the assigned approach, participant tolerance, successful acquisition of each clinically indicated vital sign, and the reasons for any unsuccessful initiation, discontinuation, or measurement. These outcomes will be reported descriptively and will not determine RAG progression to a definitive trial.

Secondary aim: To identify the most appropriate primary outcome for the definitive trial using the following hierarchy: (1) caregiver and participant preference (time of completion, r-FLACC and CFS, or composite outcome) and (2) data quality and fullness of time of completion and r-FLACC and CFS (≥80% completeness without errors).

Secondary hypothesis: We hypothesize that caregivers and participants will prioritize the composite outcome (time completion without increase in distress) 2.0 WHY IS THE TRIAL NEEDED NOW? Autistic children face many systemic barriers to receiving timely, accessible, and proper neurodiversity-affirming care within the ED .9,17,18,32 Common obstacles encountered by children with ASD and their families include: a shortage of ASD specialists and resources especially within rural communities, lack of clinical knowledge and training, inaccurate diagnoses, and societal stigma.31. Distress frequently leads to abnormal vital signs, particularly HR and RR, which are also critical indicators of severe disease (e.g. sepsis) and essential for reliable clinical assessment. Abnormal vitals resulting from environmental distress in autistic patients rather than underlying pathology may lead to unnecessary investigations, potential harm, or masking of underlying pathology. 17,18 Local McMaster Children's Hospital (MCH) ED data over the past fiscal year highlights that one in five autistic children do not have T, HR or SpO2 readings duration their ED stay, whereas the standard is to have a full set of vitals at triage then every 2 hours while in the ED. There is a clear need for complete, timely and comfortable vital sign collection for this underserved group, leading to better care experiences for patients, caregivers, and clinicians.

Wearable monitors such as the Masimo Radius PPG and Radius T may address these challenges by enabling physical, contactless assessments, which will prevent repeated interruptions and unobtrusive monitoring. This pilot RCT will assess workflow integration, device tolerance, and data quality in the real-world context of pediatric emergency care for autistic children.

This study targets intersecting priorities in pediatric emergency medicine, health equity, and digital innovation. No direct benefit to individual participants is guaranteed. If wearable monitoring proves feasible, acceptable, and safe, potential future benefits include: (1) improving the experience, safety, and dignity of future patients by reducing distress and reliance on coercive interventions;19 (2) supporting timely clinical decision-making and efficient resource use through more reliable vital-sign acquisition; (3) advancing health equity for a population that faces systemic barriers to humane, effective care; (4) identifying logistical and training needs; and (5) informing a future multicentre trial through PERC.

A comprehensive search of ClinicalTrials.gov revealed no registered trials, and a literature review conducted during trial preparation found no reports of wearable-device use in this population, underscoring the novelty of the approach.20,21,22,23 The trial will be registered on ClinicalTrials.gov before recruitment or enrollment of the first participant, and the registration number will be provided to HiREB through the Correspondence feature in eREB before recruitment begins. Innovations include technology repurposed for autistic children; integration of patient-centred outcomes such as speed, behavioural distress, and acceptability;24 an implementation-oriented design with scale-up plans through PERC; and an equity focus aligned with patient and caregiver priorities.25 The co-chair of the MCH Family Advisory Council and a caregiver of an autistic child helped shape the trial and will continue to provide structured input, including review of patient-facing materials. Findings will inform a future multicentre trial and sensory-friendly ED protocols.

If wearable monitors prove faster, accurate, and well-tolerated for autistic children, they could significantly improve pediatric ED care. Faster vital sign collection enables earlier clinical decision-making, reduces overall visit times, and prevents repeated attempts that distress children and delay care. Reduced distress can improve cooperation, lower the risk of escalating behaviors, and create a calmer environment for families and staff. For clinicians, streamlined monitoring could improve workflow efficiency, make nurses available to conduct their other responsibilities, improve evaluation accuracy, and reduce interruptions to other critical tasks. At the healthcare system level, these benefits could translate into better patient fewer resource-intensive encounters, and improved satisfaction scores. Adoption of wearable technology could also benefit other populations who have difficulty with traditional monitoring, expanding the impact to other neurodiverse children and the broader pediatric and adult care settings.

3.0 HOW WILL THE RESULTS OF THIS TRIAL BE USED? We expect this pilot trial to demonstrate that a definitive multi-centre trial is feasible, meeting our predefined progression thresholds. We anticipate that caregivers and participants will identify the composite outcome of timely completion of vital signs without moderate or severe distress as the most meaningful measure, and that this outcome will be feasible and reliable to collect. We anticipate that wearable monitoring can shorten the time needed to obtain vital signs without increasing distress and will be rated as acceptable by caregivers and staff. These outcomes will confirm feasibility, guide the choice of the primary outcome, and provide critical data to inform the design and sample size of the future definitive trial.

4.0 ANTICIPATED RISKS AND MITIGATION Anticipated operational and study-related risks include recruitment shortfalls, protocol adherence below progression thresholds, poor participant tolerance of the assigned monitoring approach, unsuccessful acquisition of one or more clinically indicated vital signs, incomplete study-data collection, device malfunction or connectivity failure, contamination, and data-capture failure. Application or continued wearing of the wearable sensors may cause transient discomfort or distress and may result in skin irritation or injury.

Behavioural escalation may occur during routine emergency care. In some circumstances, the treating clinical team may independently determine that physical restraint or sedation is clinically necessary to obtain essential assessments or provide treatment. These decisions will be based solely on the participant's clinical needs, will remain entirely at the discretion of the treating clinical team, and will not be directed by the research team. Physical restraint or sedation will not be used to initiate, continue, or complete any research procedure.

Mitigation strategies include a sensory-adapted monitoring pathway, a two-stage informed consent process, standardized application procedures, caregiver involvement, developmentally appropriate communication, individualized behavioural supports, immediate discontinuation of research-specific procedures if significant distress or refusal occurs, real-time REDCap timestamps with weekly audits, training of delegated research personnel, backup device inventory, and paper CRF backups.

A RAG dashboard for the three primary trial-feasibility outcomes-participant retention, protocol adherence, and completeness of required study data-will be reviewed weekly. Prespecified corrective actions will be implemented for Amber performance. Red feasibility performance will trigger formal review and potential study redesign. The study will be paused if a prespecified safety stopping rule is met or another safety concern requires formal review.

Privacy safeguards will comply with the Personal Health Information Protection Act (PHIPA), including role-based REDCap access, secure institutional storage of identifiable information, and restricted access to study records. The REDCap database will be hosted by the Population Health Research Institute. Wearable monitoring devices used in this study will not transmit identifiable participant information to Masimo, other external vendors, or external cloud-based systems. Study records may be reviewed by authorized study personnel and, where required for monitoring, auditing, or regulatory oversight, by HiREB, authorized Hamilton Health Sciences institutional monitors, and applicable regulatory authorities.

If a participant demonstrates significant distress, refuses, or is unable to tolerate the assigned monitoring approach, research-specific procedures will stop. The treating clinical team will determine how clinically indicated vital signs should be obtained using the usual clinical approach, independently of study participation. Decisions regarding behavioural support, timing of assessment, restraint, sedation, or other clinical interventions will remain entirely at the discretion of the treating clinical team. The outcome of the assigned monitoring attempt and the reason for discontinuation will be recorded as intervention-feasibility outcomes, where applicable.

The Masimo Radius PPG is contraindicated in patients with known allergic reactions or hypersensitivity to foam rubber products, adhesive tape, or components of the device adhesive. The sensor site will be assessed according to the manufacturer's instructions and routine clinical practice to ensure adequate adhesion, circulation, and skin integrity. Participants with skin conditions, compromised skin integrity, or other circumstances preventing safe device placement will not undergo wearable-device application.