Validation of Fitbit Measurements in Hospitalized General Medicine Patients

Patients admitted to the General Internal Medicine ward are sick and in need of monitoring that cannot be provided at home or treatments best administered in hospital. Standard care currently includes vital signs measurements and in some cases ECG. Wearable devices that continuous monitor patients could provided added information to improve the care of inpatients. This could include more monitoring and catching deterioration before it happens. Wearables have been shown to be largely accurate for monitoring heart rate, however it is still necessary to determine if they can reliably measure sleep, activity, and other health metrics. For this, study investigators are evaluating the validity of FitBit Sense 2 (or other FitBit devices) for measurement of sleep, activity, heart rate, respiratory rate, and oxygen saturation.

Study Overview

• Status: Active, not recruiting
• Conditions: GIM Diagnosis; Medicine; Admission to GIM

• Study Type: Observational
• Enrollment (Estimated): 100

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5G2C4
      • University Health Network

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The population will be General Internal Medicine inpatients on the GIM wards. Patients who can provide informed consent will be approached for enrollment. Exclusion criteria are patients who are purely palliative and therefore in which vital sign measurement would be inappropriate.

Description

Subject inclusion criteria.

• General internal medicine patients admitted to General Medicine Wards.
• Able to consent.
• 18 years of age or older

Subject exclusion criteria.

• Patients who are purely palliative "comfort measures only" where measuring vital signs would not be appropriate and will be excluded.
• To reduce the potential risk of transmitting nosocomial infections, patients under contact precautions for methicillin resistant Staphylococcus aureus (MRSA) and Clostridium difficile infections will also be excluded.
• This study will also exclude patients at risk of vascular compromise of the arm or leg on which the wearable device was to be placed, such as patients with deep venous thrombosis, dialysis fistulas, and severe upper extremity trauma.
• Expected discharge less than 24 hours

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

General internal medicine patients admitted to General Medicine Wards; Intervention: Fitbit Sense 2 (Fitbit, San Francisco, CA, USA) Gold standard devices: To compare measures, patients will be asked to wear the following for 24 hours: Sleep study device - Nox T3 chest band with oximeter. Participants will be asked to wear this for 24 hours. The Nox T3 monitors chest movement and determines sleep stages. It is paired with a Nonin oximeter. This provides continuous oxygen saturation monitoring as well as heart rate and respiratory rate.; Step counter - An ankle-worn Stepwatch Activity Monitor which has been validated in hospital patients who move slowly.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fitbit Sense 2 vs. StepWatch for activity (step count)	Comparisons of step counts between Fitbit and Modus StepWatch	Collected over 24 hours in 1 min bins
Fitbit Sense 2 vs. Nox T3 for heart rate (bpm)	Comparisons of HR between Fitbit and Nox pulse oximeter	Fitbit collected over 24 hours in 1 min bins and Nox T3 collected during nighttime sleep in 1 sec bins
Fitbit Sense 2 vs. Nox T3 for respiratory rate (breaths per minute)	Comparisons of RR between Fitbit and Nox RIP (respiratory inductive plethysmograph)	Fitbit collected over 24 hours in 1 min bins and Nox T3 collected during nighttime sleep in 1 sec bins.
Fitbit Sense 2 vs. Nox T3 for oxygen saturation (SpO2, %)	Comparisons of SpO2 between Fitbit and Nox T3	Fitbit collected over 24 hours in 1 min bins and Nox collected during nighttime sleep in 1 sec bins.
Fitbit Sense 2 vs. Nox T3 for total sleep time (min)	Comparisons of sleep TST between Fitbit and Nox T3	Fitbit and Nox T3 collected during nighttime sleep (1 night)
Fitbit Sense 2 vs. Nox T3 for sleep efficiency (%)	Comparisons of SE between Fitbit and Nox T3	Fitbit and Nox T3 collected during nighttime sleep (1 night)
Fitbit Sense 2 vs. Nox T3 for sleep stages (%, min)	Comparisons of sleep stages (NREM - stage 1-3, REM) between Fitbit and Nox T3	Fitbit and Nox T3 collected during nighttime sleep (1 night)
Fitbit Sense 2 vs. Nox T3 for wake after sleep onset (min)	Comparisons of WASO between Fitbit and Nox T3	Fitbit and Nox T3 collected during nighttime sleep (1 night)
Fitbit Sense 2 vs. Nox T3 for time of sleep onset and wake time	Comparisons of sleep onset time and wake time between Fitbit and Nox T3	Fitbit and Nox T3 collected during nighttime sleep (1 night)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fitbit Sense 2 vs. Sleep Diary for total sleep time (min)	Comparisons of total sleep time between Fitbit and self-reported sleep diary.	Collected during nighttime sleep (1 night)
Fitbit Sense 2 vs. Sleep Diary for sleep efficiency (%)	Comparisons of sleep efficiency between Fitbit and self-reported sleep diary.	Collected during nighttime sleep (1 night)
Fitbit Sense 2 vs. Sleep Diary for time of sleep schedule	Comparisons of time of sleep between Fitbit and self-reported sleep diary.	Collected during nighttime sleep (1 night)
Fitbit Sense 2 vs. Sleep Diary for wake after sleep onset (min)	Comparisons of WASO between Fitbit and self-reported sleep diary.	Collected during nighttime sleep (1 night)
Subgroup analysis based on gender	Gender-based subgroup analysis of outcomes	Collected at study baseline
Subgroup analysis based on comorbidities	Descriptive data on participant comorbidities (e.g., presence of mobility limiting conditions, etc; yes/no) or subgroup analysis by comorbidities	Collected at study baseline
Subgroup analysis based on use of walking aids	Subgroup analysis by walking aid usage or descriptive data on walking aid use among participants (e.g., yes vs. no)	Collected at study baseline

Collaborators and Investigators

• Sponsor: University Health Network, Toronto

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2025
• Primary Completion (Actual): August 31, 2025
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: July 29, 2025
• First Submitted That Met QC Criteria: November 13, 2025
• First Posted (Actual): November 17, 2025

Study Record Updates

• Last Update Posted (Actual): November 17, 2025
• Last Update Submitted That Met QC Criteria: November 13, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Keywords: sleep; wearable; heart rate
• Other Study ID Numbers: 24-5399

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: This study requested sharing of IPD in the ethics application.