0385 Sleep and Health in United States Air Force Helicopter Airlift Squadron Working 24-Hour On-Call Schedules as Measured by a Consumer Wearable

Abstract Introduction The 459th Airlift Squadron is a United States Air Force (USAF) helicopter airlift squadron stationed at Yokota Air Base outside Tokyo, Japan. The 459th operates on a 24-hour on-call shift to provide responsive airlift support for distinguished visitors, conduct aeromedical evacuations, search and rescue, and priority airlift missions throughout the Pacific. Several Pilots and Flight Engineers in the 459th received a consumer wearable (Oura™ Ring, Generation 2 or 3) for their personal use. The goal of this pilot study is to explore the impact of 24-hour on-call schedules on service members’ sleep and health over a 30-day period. Methods N=5 service members with a consumer wearable downloaded their personal data and sent the CSV file to the research team. Summary statistics (M±STD) were computed for average bedtime and wake time, time in bed (TIB) and total sleep time (TST) in minutes, sleep efficiency (SE), average resting heart rate (HR; bpm), heart rate variability (HRV; ms), temperature deviation (°C), and step counts across time. Potential changes in sleep and health variables over time were explored using simple linear regression. Results Each participant provided at least 30 days’ worth of wearable data which coincided with active duty periods at Yokota Air Base between October 2024- 2025. Participants did not cross time zones during the study period. Average bedtime was 22:15±1:41 and average wake time was 6:34±1:20. Average TIB was 501±92 minutes, TST was 437±78 minutes, and SE was 88±7%. Average resting HR was 58±9 bpm and HRV was 69±37 ms. Average step count was 9648±4623. Temperature deviation was 0.00±0.26°C. Linear regression did not indicate a strong effect of time on changes to any variables (all R2< 0.2). Conclusion Sleep and health metrics measured by a consumer wearable fell within normal ranges for USAF Airlift Squadron service members working 24-hour on-call schedules. These preliminary data suggest that on-call schedules do not seriously disturb health metrics. These data only represent current wearable users and may not generalize to service members without access to a wearable. The next step in this study is to analyze participants’ subjective fatigue and stress via a one-time online survey. Support (if any) No external support