# Sleep Quality in Shift-Working Nurses: Subjective and Objective Evaluation

## TL;DR

Shift-working nurses often underestimate their poor sleep quality, and objective data shows that rotating shifts lead to worse sleep outcomes.

## Contribution

This study reveals a discrepancy between subjective and objective sleep quality assessments in shift-working nurses and links rotating shifts to objectively poorer sleep.

## Key findings

- Most nurses subjectively rated their sleep as good, but all were objectively classified as poor sleepers.
- Nurses working only day shifts had better objective sleep scores and longer sleep duration compared to those on rotating shifts.
- Objective measurements showed rotating shift work is associated with significantly poorer sleep quality.

## Abstract

Public health relevance—How does this work relate to a public health issue?
Highlights the growing burden of sleep disturbances among nurses, a workforce essential for maintaining patient safety and healthcare quality.Addresses the impact of shift work on circadian health, an important determinant of long-term wellbeing and occupational functioning.

Highlights the growing burden of sleep disturbances among nurses, a workforce essential for maintaining patient safety and healthcare quality.

Addresses the impact of shift work on circadian health, an important determinant of long-term wellbeing and occupational functioning.

Public health significance—Why is this work of significance to public health?
Demonstrates a clear discrepancy between subjective and objectively measured sleep quality, underscoring the need for reliable assessment tools in occupational health.Provides evidence that shift work is associated with objectively poorer sleep, supporting public health efforts aimed at improving working conditions for healthcare workers.

Demonstrates a clear discrepancy between subjective and objectively measured sleep quality, underscoring the need for reliable assessment tools in occupational health.

Provides evidence that shift work is associated with objectively poorer sleep, supporting public health efforts aimed at improving working conditions for healthcare workers.

Public health implications—What are the key implications or messages for practitioners, policy makers and/or researchers in public health?
Calls for targeted interventions and organizational changes to improve sleep health among shift-working nurses, which may enhance performance and reduce fatigue-related errors.Emphasizes the importance of integrating wearable technology into routine occupational health monitoring to better detect and address sleep-related risks.

Calls for targeted interventions and organizational changes to improve sleep health among shift-working nurses, which may enhance performance and reduce fatigue-related errors.

Emphasizes the importance of integrating wearable technology into routine occupational health monitoring to better detect and address sleep-related risks.

Background: It is well-known that rotating shift work disrupts the circadian rhythm and sleep quality in nurses. With this study, we aimed to compare subjectively and objectively measured sleep quality in nurses, specifically focusing on any differences that arose in relation to shift work. Methods: This prospective, observational, cross-sectional study was conducted in 2025 in Croatia; a total of 140 nurses participated. Sleep was assessed using the Pittsburgh Sleep Quality Index (PSQI) and FitBit Charge 3 smartwatch, which monitored sleep over an eight-day period. Results: Most nurses rated their sleep as good or very good, but according to the PSQI questionnaire, all participants were classified as poor sleepers (PSQI > 5). Objective smartwatch measurements showed that nurses working only day shifts had higher sleep scores (median 77, IQR 75–80 vs. 73, IQR 68–76; p < 0.001), significantly longer total sleep duration (median 6.4, IQR 6.3–7.1 vs. 5.5, IQR 5.2–6.2 h; p < 0.001), and longer durations of all sleep stages compared with those working rotating shifts. Conclusions: Most nurses subjectively rated their sleep as good or very good; however, according to the PSQI questionnaire results, all were classified as poor sleepers, with no significant difference related to shift work. Objective measurements using the smartwatch indicated that rotating shift work is associated with significantly poorer sleep quality.