Step count and activity may be able to; 1.

Risk stratify patients preoperatively,

1.

To evaluate the use of smartwatches in a perioperative cohort in order to assess feasibility, test recruitment, compliance and data collection.

A prospective observational cohort study of step-count and activity in fifty adult patients awaiting elective major abdominal surgery at a large UK teaching hospital.

All patients will be issued with a smartwatch without randomisation or blinding. There is no intervention; this study seeks to determine the feasibility of the device and baseline patient physical activity, without influencing patient or clinician behaviour.

We will recruit 50 patients between March 2025 and December 2025 in a single tertiary referral centre.

Inclusion criteria; •

Adult patient (age ≥ 18 years),

Exclusion criteria •

Lack of access to smartphone in household,

The feasibility of smartwatches as a perioperative tool to assess patient fitness and activity will be assessed. Feasibility is defined as stop (not feasible in current format), modify (feasible with modification) and go (feasible in current format) criteria; •

Proportion of eligible patients recruited (<20%, 20-30%, >30%),

•

Smartwatch data

Patients will be identified through screening of the pre-assessment CPET list. A member of the patient’s clinical team will introduce the trial and ensure consent for research contact. The research team will discuss the study and provide a written patient information sheet; consent will be taken at the clinic or over the phone on the subsequent day(s). Those consented by phone will have written confirmation recorded by a member of the research team according to local practice. Patients will then confirm consent and sign the consent form on the day of surgery.

Older patients may feel digitally excluded, be less inclined to exercise or have lower activity levels, and be less likely to consent. Expected event rates for post-operative complications will vary with regard to both co-morbidity and age. Hence, intentional sampling ( Table 1) will reduce potential bias when assessing association with perioperative outcomes and facilitate a representative sample of the higher-risk CPET population.

The trial was authorised by South Central - Berkshire B Research Ethics Committee (REC Reference: 24/SC/0364) on 12/11/2024 and is sponsored by the University Hospitals Plymouth NHS Trust. The study will be conducted at Derriford Hospital, University Hospitals Plymouth. Written consent is obtained from participants using the REC approved Informed Consent Form. Participants were consented using the Research Ethics committee approved informed consent form either in person or via the telephone. This process was managed according the the Sponsor’s local policy.

As a feasibility study, a formal sample size calculation has not been performed. Fifty patients will be recruited, providing sufficient data to answer our feasibility questions. A sample size of 50 participants would allow a recruitment rate of 30% to be estimated with an 90% confidence interval of ±10%. ²⁴

Local data shows that 80 patients per month have a preoperative CPET of which 90% meet the inclusion criteria. With a 30% recruitment rate this provides an ample patient pool to meet our recruitment target.

Participants will wear a Garmin vivofit 4 smartwatch during waking hours for 2 weeks (minimum 7 days, see below) prior to surgery and 4 weeks (minimum 7 days) post-operatively. Device data will be collected continuously during watch use. Participants will be set up with a device either at the time of consent, or the device will be sent to the patient remotely with usage instructions and a follow up phone call to aid device set up. Cross-sectional study data ²⁵ suggests that six days’ monitoring are needed to reliably capture habitual activity in all activity intensities. As such, a minimum of 7 days’ of data is set as our feasibility metric. Commercially available watches have specifically been chosen as, although research specific devices exist, these are likely to represent an easily applicable prehabilitation tool.

(See extended data for data collection summary)

Patients will be followed up to day 30 post-operatively. Data will be collected through inpatient review of notes, telephone call following hospital discharge and digital questionnaire completion via smartphone. All data will be collected online either within a data safe haven ( REDCap) ( https://project-redcap.org/ ) or via the fully GDPR-compliant online Fitrockr ( https://www.fitrockr.com/) platform, targeting a paperless study. The Fitrockr platform provides an efficient approach to collecting questionnaire data with easy tracking to maximise completion. Smartwatch data is tracked in real time to facilitate rapid identification and correction of issues such as participants not uploading data.

Electronic data captured in REDCap will be stored on the Sponsor’s centralised virtual storage infrastructure, split between two local data centres, and subject to the Sponsor’s Information Security and Network Security Policies. All electronic data are regularly backed up and retained for 30 days. The smartwatch data will be uploaded via the participant’s smartphone, pseudonymised, collected and centralised by the Fitrockr platform ( Figure 2). A number of participant questionnaire responses will be entered by participants themselves via their smartphone directly into the software platform. A relative’s smartphone can be used if required, to avoid excluding those without a smartphone, as long as proximity to the phone can be maintained at frequent intervals to allow syncing. Participants will be supported with data input via a telephone call from the research team, if required.

A locally-designed questionnaire co-developed with patients will assess user interaction with, and experience of, the smartwatch devices. ²⁶

The trial will be reported in accordance with the CONSORT statement extension for pilot and feasibility trials. ²⁶ Population-level descriptive statistics will be reported for feasibility and secondary outcomes. No statistical comparisons will be undertaken.