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. 2025 Aug;34(4):e14026.
doi: 10.1111/jsr.14026. Epub 2023 Aug 26.

Pilot feasibility testing of biomathematical model recommendations for personalising sleep timing in shift workers

Prerna Varma  1 , Svetlana Postnova  2 , Andrew J K Phillips  1 , Stuart Knock  2 , Mark E Howard  1   3   4 , Shantha M W Rajaratnam  1   5   6 , Tracey L Sletten  1
Affiliations

Pilot feasibility testing of biomathematical model recommendations for personalising sleep timing in shift workers

Prerna Varma et al. J Sleep Res. 2025 Aug.

Abstract

Sleep disturbances and circadian disruption play a central role in adverse health, safety, and performance outcomes in shift workers. While biomathematical models of sleep and alertness can be used to personalise interventions for shift workers, their practical implementation is undertested. This study tested the feasibility of implementing two biomathematical models-the Phillips-Robinson Model and the Model for Arousal Dynamics-in 28 shift-working nurses, 14 in each group. The study examined the overlap and adherence between model recommendations and sleep behaviours, and changes in sleep following the implementation of recommendations. For both groups combined, the mean (SD) percentage overlap between when a model recommended an individual to sleep and when sleep was obtained was 73.62% (10.24%). Adherence between model recommendations and sleep onset and offset times was significantly higher with the Model of Arousal Dynamics compared to the Phillips-Robinson Model. For the Phillips-Robinson model, 27% of sleep onset and 35% of sleep offset times were within ± 30 min of model recommendations. For the Model of Arousal Dynamics, 49% of sleep onset, and 35% of sleep offset times were within ± 30 min of model recommendations. Compared to pre-study, significant improvements were observed post-study for sleep disturbance (Phillips-Robinson Model), and insomnia severity and sleep-related impairments (Model of Arousal Dynamics). Participants reported that using a digital, automated format for the delivery of sleep recommendations would enable greater uptake. These findings provide a positive proof-of-concept for using biomathematical models to recommend sleep in operational contexts.

Keywords: alertness; circadian rhythms; healthcare; shift‐work disorder; sleep disorder.

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Conflict of interest statement

Dr Varma has no conflicts of interest to declare. Dr Postnova was Theme and Project Leader and received grants for research from the Cooperative Research Centre for Alertness, Safety and Productivity. Dr Phillips has received research funding from Versalux and Delos, he was an investigator on projects under the Cooperative Research Centre for Alertness, Safety and Productivity, and he is co‐founder/director of Circadian Health Innovations Pty Ltd. Dr Knock has no conflicts of interest to declare. Dr Howard was Theme Leader and received grants for research from the Cooperative Research Centre for Alertness, Safety and Productivity. Dr Rajaratnam has unpaid appointments at the CRC for Alertness, Safety and Productivity, Australia, and the Sleep Health Foundation. Dr Rajaratnam also is supported on grants from Vanda Pharmaceuticals, Philips Respironics, Cephalon, Rio Tinto, BHP Billiton, and Shell. Dr Rajaratnam also has received other support from Optalert, Compumedics, Teva Pharmaceuticals and Circadian Therapeutics, through his institution. He is a member of the National Sleep Foundation Sleep Timing Variability Consensus Panel, for which he was paid an honorarium through his institution. Dr Sletten was a Project Leader and received grants for research from the Cooperative Research Centre for Alertness, Safety and Productivity. [Correction added on 16 October 2023, after first online publication: Conflict of Interest Statement was updated in this version.]

Figures

FIGURE 1
FIGURE 1
Example raster plots showing recommendations (dark blue) and actual sleep (grey) of participants assigned to the Phillips–Robinson Model and the Model of Arousal Dynamics. Shift rotations for participants in both examples were aligned, illustrated in orange, and personal commitments are in yellow.
FIGURE 2
FIGURE 2
The proportion of sleep onset and offset times between ≤30, 31–60, 61–90, 91–120, >120 min of model recommendations during the Habitual Week and Recommendation Week for both models.
FIGURE 3
FIGURE 3
Differences in sleep duration, insomnia symptoms, sleep‐related impairment, and sleep from pre‐ and post‐study across both models. *p < 0.05; **p < 0.01; ***p < 0.001.
FIGURE 4
FIGURE 4
Themes from participants’ feedback to improve the practicality and implementation of sleep recommendations from models.
See this image and copyright information in PMC

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