Issues related to measuring and interpreting objectively measured sedentary behavior data

The use of objective measures of sedentary behavior has increased over the past decade; however, as is the case for objectively measured physical activity, methodological decisions before and after data collection are likely to influence the outcomes. The aim of this article is to review the evidence on different methodological decisions made by researchers when examining sedentary behavior. The different issues researchers may encounter when measuring sedentary behavior have been divided into (a) activity monitor placement; (b) epochs, cut points, and non-wear time definitions; (c) criteria for sedentary behavior bouts and breaks; and (d) combining motion and posture data. This article recommends that (a) activity monitors should be placed on the thigh and combined with a data reduction approach that estimates inclination, especially in children and adults; and (b) researchers should clearly report their data processing decisions to enhance the ability to evaluate and compare studies in the future. However, the article also highlights a dearth of methodological evidence to inform the use of objective measures of sedentary behavior. Based on the gaps in the literature, research recommendations, which require addressing to develop a best practice protocol when measuring sedentary behavior objectively, have been made

Barriers and facilitators of physical activity, sedentary and sleep behaviours in 3 to 4-year-old children from low-income families : a study protocol

Background: This study will evaluate the barriers and facilitators that families experience in adhering to the 24-hour movement behaviours guidelines as outlined by World Health Organisation (WHO). Methods: The study is a mixed-methods study and will recruit between 20 to 30 low-income families with children aged 3- to 4-years living in Scotland. For the quantitative part, children will be asked to wear an Actigraph (GT3X +) accelerometer to measure physical activity, sedentary behaviour, and sleep. Parents/guardians will be asked to keep an activity diary outlining when their child has had to remove the device (i.e., showering, bathing, swimming) and record the child’s screen time each day. Once the data has been analysed, a unique activity profile chart will be sent out to each family illustrating their child’s 24-hour movement behaviours (i.e., time spent active, time spent sedentary and on screens, time spent sleeping). The activity profile will provide a day-by-day output as well as a weekly average for each of the 24-hour movement behaviours. Qualitative data will be collected using the Asynchronous Remote Communities method (ARC). The ARC involves participants completing activities using an online closed Facebook group. Parents/guardians of 3- to 4-year-old children will be asked to engage in group discussion tasks using the private and closed-group online platform (a minimum of 6 and a maximum of 8 families per discussion group). The quantitative data collated from the questionnaire and activity monitor will be presented through descriptive analysis and after the 6-week asynchronous process is complete, qualitative data will be collated and analysed using Braun and Clarke’s reflexive approach to thematic analysis. Discussion: The data collected will provide an understanding of what barriers and facilitators parent’s/guardians’ experience in relation to adhering to the 24-hour movement behaviour guidelines. This could potentially lead to the design and implementation of support and interventions to help families struggling to adhere to the guidelines

A mixed methods evaluation of a digital intervention to improve sedentary behaviour across multiple workplace settings

Background: Prolonged sedentary behaviour (SB) is associated with risk of chronic diseases. Digital interventions in SB require mixed method evaluations to understand potential for impact in real-world settings. In this study, the RE-AIM QuEST evaluation framework will be used to understand the potential of a digital health promotion application which targets reducing and breaking up SB across multiple workplace settings. Methods: Four companies and 80 employees were recruited to use a digital application. Questionnaires were used to measure SB, and additional health and work-related outcomes at baseline, one month, three month and six month follow-up. Qualitative data was collected through focus groups with employees and interviews with stakeholders. Questionnaire data was analysed using Wilcoxon Sign Rank tests and qualitative data was thematically analysed. Results: The digital application significantly increased standing time at one month for the total group and transitions per hour in one of the companies. Facilitators and barriers were identified across RE-AIM. Conclusions: Addressing the barriers which have been identified, while maintaining the positive attributes will be critical to producing an effective digital application which also has the potential for impact in the real world

Pragmatic evaluation of the Go2Play Active Play intervention on physical activity and fundamental movement skills in children

Active play is a novel approach to addressing low physical activity levels and fundamental movement skills (FMS) in children. This study aimed to determine if a new school-based, ‘Go2Play Active Play’ intervention improved school day physical activity and FMS. This was a pragmatic evaluation conducted in Scotland during 2015–16. Participants (n = 172; mean age = 7 years) were recruited from seven primary schools taking part in the 5-month intervention, plus 24 participants not receiving the intervention were recruited to act as a comparison group.189 participants had physical activity measured using an Actigraph GT3X accelerometer at baseline and again at follow-up 5 months later. A sub-sample of participants from the intervention (n = 102) and comparison (n = 21) groups had their FMS assessed using the Test of Gross Motor Development (TGMD-2) at baseline and follow-up. Changes in school day physical activity and FMS variables were examined using repeated measures ANOVA. The main effect was ‘group’ on ‘time’ from baseline to follow-up. Results indicated there was a significant interaction for mean counts per minute and percent time in sedentary behavior, light intensity physical activity and moderate to vigorous physical activity (MVPA) (all p < 0.01) for school day physical activity. There was a significant interaction for gross motor quotient (GMQ) score (p = 0.02) and percentile (p = 0.04), locomotor skills score and percentile (both p = 0.02), but no significant interaction for object control skills score (p = 0.1) and percentile (p = 0.3). The Go2Play Active Play intervention may be a promising way of improving physical activity and FMS but this needs to be confirmed in an RCT

Appropriateness of the definition of 'sedentary' in young children : whole-room calorimetry study

The present study aimed to measure the energy cost of three common sedentary activities in young children to test whether energy expended was consistent with the recent consensus definition of 'sedentary' as 'any behaviour conducted in a sitting or reclining posture and with an energy cost ≤1.5 metabolic equivalents (METs)' (Sedentary Behaviour Research Network, 2012).  This was an observational study

Practical utility and reliability of whole-room calorimetry in young children

The use of whole-room calorimetry (WRC) in young children can increase our understanding of children's energy balance. However, studies using WRC in young children are rare due to concerns about its feasibility. To assess the feasibility of WRC in young children, forty children, aged 4-6 years, were asked to follow a graded activity protocol while in a WRC. In addition, six children participated in two additional resting protocols to examine the effect of diet-induced thermogenesis on resting energy expenditure (REE) measures and the reliability of REE measurement. Refusals to participate and data loss were quantified as measures of practical utility, and REE measured after an overnight fast and after a 90-min fast were compared. In addition, both were compared to predicted BMR values using the Schofield equation. Our results showed that thirty (78·9 %) participants had acceptable data for all intensities of the activity protocol. The REE values measured after a 90-min fast (5·07 (sd 1·04) MJ/d) and an overnight fast (4·73 (sd 0·61) MJ/d) were not significantly different from each other (P = 0·472). However, both REE after an overnight fast and a 90-min fast were significantly higher than predicted BMR (3·96 (sd 0·18) MJ/d) using the Schofield equation (P = 0·024 and 0·042, respectively). We conclude that, with a developmentally sensitive approach, WRC is feasible and can be standardised adequately even in 4- to 6-year-old children. In addition, the effect of a small standardised breakfast, approximately 90 min before REE measurements, is likely to be small

Predictive validity and classification accuracy of actigraph energy expenditure equations and cut-points in young children

Objectives: Evaluate the predictive validity of ActiGraph energy expenditure equations and the classification accuracy of physical activity intensity cut-points in preschoolers. Methods: Forty children aged 4–6 years (5.3±1.0 years) completed a ~150-min room calorimeter protocol involving age-appropriate sedentary, light and moderate-to vigorous-intensity physical activities. Children wore an ActiGraph GT3X on the right mid-axillary line of the hip. Energy expenditure measured by room calorimetry and physical activity intensity classified using direct observation were the criterion methods. Energy expenditure was predicted using Pate and Puyau equations. Physical activity intensity was classified using Evenson, Sirard, Van Cauwenberghe, Pate, Puyau, and Reilly, ActiGraph cut-points. Results: The Pate equation significantly overestimated VO2 during sedentary behaviors, light physical activities and total VO2 (P<0.001). No difference was found between measured and predicted VO2 during moderate-to vigorous-intensity physical activities (P = 0.072). The Puyau equation significantly underestimated activity energy expenditure during moderate-to vigorous-intensity physical activities, light-intensity physical activities and total activity energy expenditure (P<0.0125). However, no overestimation of activity energy expenditure during sedentary behavior was found. The Evenson cut-point demonstrated significantly higher accuracy for classifying sedentary behaviors and light-intensity physical activities than others. Classification accuracy for moderate-to vigorous-intensity physical activities was significantly higher for Pate than others. Conclusion: Available ActiGraph equations do not provide accurate estimates of energy expenditure across physical activity intensities in preschoolers. Cut-points of ≤25counts⋅15 s−1 and ≥420 counts⋅15 s−1 for classifying sedentary behaviors and moderate-to vigorous-intensity physical activities, respectively, are recommended

Pilot testing of a nudge-based digital intervention (Welbot) to improve sedentary behaviour and wellbeing in the workplace

Welbot is a nudge-based digital intervention that aims to reduce sedentary behaviour and improve physical and mental wellbeing at work. The purpose of this study was to pilot test the Welbot intervention. Forty-one (6M/35F) University staff (M age = 43-years) participated in this study, which was a single arm repeated measures trial conducted over three weeks of intervention. The primary outcome was sedentary behaviour (measured subjectively and objectively) and secondary outcomes included: mental wellbeing, procrastination, depression, anxiety and stress, and work engagement. A subset of participants (n = 6) wore an ActivPAL to objectively measure activity data, while another subset of participants (n = 6) completed a qualitative semi-structured interview to ascertain experiences of using Welbot. Following the intervention, a Friedman non-parametric test revealed that participants self-reported significantly less time sitting and more time standing and objectively recorded more steps at the week-1 follow-up. A series of paired t-tests exhibited that changes in all secondary outcomes were in the expected direction. However, only improvements in depression, anxiety, and stress were significant. After using Welbot, thematic analysis demonstrated that participants perceived they had a positive behaviour change, increased awareness of unhealthy behaviours at work, and provided suggestions for intervention improvement. Overall, findings provided indications of the potential positive impact Welbot may have on employees’ wellbeing, however, limitations are noted. Recommendations for intervention improvement including personalisation (e.g., individual preferences for nudges and the option to sync Welbot with online calendars) and further research into how users engage with Welbot are provided

"Building your best day": co-producing an intervention to reduce the large and rapidly growing inequalities in childhood obesity in Scotland : Stakeholder Report Spring/Summer 2021

Stakeholder report produced as part of early intervention development work for early years obesity prevention. Four online focus groups were run with pre-school education and parenting charity representatives (n=8), senior NHS public health and health promotion staff (n=6), and caregivers (parents and early years practitioners; n=4). Thematic analysis identified seven main themes and nine sub-themes. This report describes these themes, illustrated with connected quotes and tabulates ways in which the stakeholder voice can be included in the intervention development cycle. This report begins to chart the direction of intervention development and evaluation in our pre-schooler obesity inequalities research programme into the future

Public health surveillance of physical activity in adolescents and adults in Namibia : a cross-sectional validation of activity questionnaires against accelerometry

Background: Monitoring population-level physical activity is crucial for examining adherence to global guidelines and addressing obesity. This study validated self-reported moderate-to-vigorous physical activity (MVPA) against an accurate device-based method in Namibia. Methods: Adolescent girls (n = 52, mean age 16.2 years [SD 1.6]) and adult women (n = 51, mean age 31.3 years [SD 4.7]) completed the PACE+/GPAQ self-report questionnaires and were asked to wear an Actigraph accelerometer for 7 days. Validity of self-reported MVPA was assessed using rank-order correlations between self-report and accelerometry, and classification ability of the questionnaires with Mann–Whitney tests, kappa's, sensitivity and specificity. Results: In the adolescents, Spearman's rank coefficients between self-reported MVPA (days/week) and accelerometry measured MVPA were positive but not significant (r = 0.240; P = 0.104). In the adults, self-reported MVPA (minutes/day) was moderately and significantly correlated with accelerometer-measured MVPA (r = 0.396; P = 0.008). In both groups, there was fair agreement between accelerometry and questionnaire-defined tertiles of MVPA (adolescents κ = 0.267; P = 0.010; adults κ = 0.284; P = 0.008), and measured MVPA was significantly higher in the individuals self-reporting higher MVPA than those reporting lower MVPA. Conclusions: The PACE+ and GPAQ questionnaires have a degree of validity in adolescent girls and adult females in Namibia, though more suitable for population than individual level measurement