# Sensor based sleep patterns and reported sleep quality in breast cancer patients undergoing neoadjuvant chemotherapy

## TL;DR

This study tracks sleep patterns in breast cancer patients during chemotherapy using sensors and finds changes in sleep duration and disturbances over time.

## Contribution

The study introduces a detailed analysis of sleep metrics during chemotherapy using sensor data and the PSQI, identifying vulnerable periods for sleep disruption.

## Key findings

- Chemotherapy may influence time spent in bed, with a decrease observed in the first seven weeks followed by a recovery.
- Sleep disturbances and insomnia symptoms increased during treatment, with 73% of patients reporting insomnia by week 15.
- Sleep timing and regularity remained unchanged despite changes in sleep duration and disturbances.

## Abstract

Breast cancer is the most diagnosed cancer in women worldwide and its treatment often leads to the onset of sleep disturbances. While much research has focused on chemotherapy’s impact on overall sleep quality through subjective measures, less attention has been given to its effects on specific sleep metrics such as duration, timing, continuity, and naps. This preliminary study addresses this gap by assessing sleep duration, timing, and regularity, using the Emfit QS device over 100 consecutive days in 24 breast cancer patients undergoing neoadjuvant chemotherapy. Additionally, we incorporated the Pittsburgh Sleep Quality Index (PSQI) to measure reported sleep quality. Our results suggest that chemotherapy may influence the duration for time spent in bed (ptrend = 0.02) measured by the Emfit QS. Duration in bed decreased over the first seven weeks (e.g., 9.3 h/day at week 1 vs. 8.5 h/day at week 8), and increased thereafter to similar amounts as those recorded in week 1 (9.0 h/day at week 15). Sleep timing and regularity, also measured by the Emfit QS, remained unchanged. Overall sleep quality, as measured by the PSQI, did not change over time. However, our analysis of the individual components of the PSQI revealed that sleep disturbances increased as treatment progressed from week 1 to week 8 (1.3 ± 0.6 to 1.7 ± 0.6; p = 0.01), concurrently with an increase in insomnia symptoms. Approximately, 33%, 63%, and 73% reported having insomnia symptoms at week 1, 8, and 15. These findings highlight critical periods during treatment when patients are vulnerable to disrupted sleep. Future research should focus on interventions to mitigate sleep disturbances, improving patient well-being and overall quality of life.

The online version contains supplementary material available at 10.1038/s41598-025-99208-0.