Research Database

Effect of intradialytic exercise on daily physical activity and sleep quality in maintenance hemodialysis patients

  • Published on Jan 23, 2018

Purpose: Physical inactivity and sleep disturbance are frequently observed and relate to poor clinical outcomes in maintenance hemodialysis patients. We aimed to investigate the effect of intradialytic exercise on daily physical activity and sleep quality, measured by an accelerometer, in maintenance hemodialysis patients. Methods: This study randomly assigned ambulatory maintenance ...


Objectively measured physical activity of hospital shift workers

  • Published on Jan 22, 2018

Objectives: Shift work may alter workers' leisure-time and occupational physical activity (PA) levels, which might be one of the potential underlying mechanisms of the negative health effects of shift work. Therefore, we compared objectively measured PA levels between hospital shift and non-shift workers. Methods: Data were used from Klokwerk+, a ...


Actigraphy-based sleep estimation in adolescents and adults: a comparison with polysomnography using two scoring algorithms

  • Published on Jan 18, 2018

Objectives: Actigraphy is widely used to estimate sleep-wake time, despite limited information regarding the comparability of different devices and algorithms. We compared estimates of sleep-wake times determined by two wrist actigraphs (GT3X+ versus Actiwatch Spectrum [AWS]) to in-home polysomnography (PSG), using two algorithms (Sadeh and Cole-Kripke) for the GT3...


Sleep patterns in children differ by ethnicity: cross-sectional and longitudinal analyses using actigraphy

  • Published on Feb 2018

Objectives: To determine whether sleep patterns (duration, timing, efficiency) differ by ethnicity. Design: Longitudinal study. Setting: Dunedin, New Zealand. Participants: A total of 939 children (48% male) aged 4-12 years (572 European, 181 Māori, 111 Pacific, 75 Asian). Measurements: All measurements were obtained at months 0, 12, and 24. Anthropometry was obtained using standard techniques, and parents completed ...


Exploring Accelerometer Versus Self-Report Sleep Assessment in Youth With Concussion

  • Published on Dec 7, 2017

Abstract: This study examines accelerometer-based and self-report assessment of sleep disturbance from a larger prospective cohort of youth 5 to 18 years of age with postconcussive injury. Twenty-one participants with self-reported sleep disturbance were evaluated using accelerometers. Participants completed the Pittsburgh Sleep Quality Index (PSQI) every 48 hours and also measured sleep via ...


Temporal and bi-directional associations between sleep duration and physical activity/sedentary time in children: An international comparison

  • Published on Jun 2018

Abstract: The purpose of this multinational and cross-sectional study was to investigate whether nighttime sleep duration was associated with physical activity (PA) and sedentary time (SED) the following day, whether daytime PA/SED were associated with sleep duration the subsequent night, and whether the associations were modified by sex and ...


Does sleep disruption mediate the effects of childhood maltreatment on brain structure?

  • Published on May 31, 2018

Background: Childhood maltreatment is associated with alterations in morphology of stress susceptible brain regions. Maltreatment is also known to markedly increase risk for psychopathology and to have an enduring disruptive effect on sleep. Objective: To determine whether abnormalities in sleep continuity have effects on brain morphometry and to evaluate the ...


Classification and Processing of 24-Hour Wrist Accelerometer Data

  • Published on 2017

Background: An important step in accelerometer data analysis is the classification of continuous, 24-hour data into sleep, wake, and non-wear time. We compared classification times and physical activity metrics across different data processing and classification methods. Methods: Participants (n = 576) from the Finnish Retirement and Aging Study (FIREA) wore an accelerometer ...



Actigraphy assessment of sleep quality among patients with acute myeloid leukaemia during induction chemotherapy

  • Published on Apr 2018

Objectives: Patients receiving induction chemotherapy for acute myeloid leukaemia (AML) anecdotally describe poor sleep, but sleep disturbances have not been well-characterised in this population. We aimed to test the feasibility of measuring sleep quality in AML inpatients using a wearable actigraphy device. Methods: Using the ActiGraph GT3X ‘watch’, we ...