Investigation of consistency in sleep quality evaluation using a Fitbit device compared to a structured questionnaire among breastfeeding mothers in Ho Chi Minh City, Vietnam

BACKGROUND A new health monitoring device called Fitbit Charge 6 has appeared on the Vietnamese market. This study aimed to evaluate the consistency between Fitbit Charge 6 and structured interview questions in measuring sleep quality among breastfeeding mothers.

RESEARCH DESIGN AND METHODS A cross-sectional study utilizing random convenience sampling was conducted in Ho Chi Minh City, Vietnam, involving 208 breastfeeding women one month postpartum. The participants used the Fitbit Charge 6 device continuously for four days and three nights to gather daily sleep information; then, they were administered a structured sleep questionnaire via home interviews.

RESULTS The correlation between the total sleep time (TST) recorded by both the device and interview was weak (r = 0.28), as was the correlation for short nap duration (r = 0.25). The agreement between the Fitbit Sleep Score and sleep satisfaction from the questionnaire was 79.9%, with a notably low kappa coefficient (0.02), indicating a lack of strong agreement.

CONCLUSION The Fitbit Charge 6 did not show reliable correlation with the subjective sleep data reported by one-month postpartum breastfeeding women. Further research employing rigorous comparative studies is necessary to assess the validity and reliability of sleep data collection methods for this demographic.