The objective measurement of physical activity and sedentary behaviour in 2-3 year olds and their parents: a cross-sectional feasibility study in the bi-ethnic Born in Bradford cohort

Background: The reported lower physical activity (PA) levels of British South Asians (SA) are suggested as a key influence in their increased risk of non-communicable diseases compared to their White British peers. Differences in objectively measured PA and sedentary behaviour (SB) between these ethnic groups have been observed during childhood (ages: 8-10 years). However, no information exists on objectively measured PA/SB in younger children, or how early in life differences in these behaviours emerge. Assessing PA/SB in the Born in Bradford (BIB) cohort study provides an opportunity to address such gaps in the literature, but previous studies have found recruiting and retaining SA participants challenging, and the feasibility of using accelerometers with SA children and parents is unknown. This study investigated the feasibility of recruiting and objectively measuring the habitual PA/SB of 2-3 year old SA and White British children and parents from the BIB study. Methods: Families were informed about the study during routine BIB assessments. Consenting families were visited at home for anthropometry measurements, interviews, material delivery and collection. Participants (child and parents) were instructed to wear the ActiGraph GT3X+ for 8 days. Descriptive statistics were computed, and ethnic differences tested (Chi-square) for recruitment uptake and compliance. Results: 160 families (30 % SA) provided contact details, and 97 (22 % SA) agreed to enter the study. White British families showed lower refusal and higher intake into the study than SA (p = 0.006). Of 89 children issued with an accelerometer, 34 % complied with the 8-day protocol (significantly less SA; p = 0.015) and 75 % provided enough days (≥3) to assess habitual PA/SB (no ethnic differences). Parental rates of compliance with the protocol did not differ between ethnicities. Issues experienced with the protocol and accelerometer use, and successful implementation strategies/procedures are presented. Conclusions: Although greater efforts may be required to recruit SA, those consenting to participate were as likely as White British to provide enough data to assess habitual PA/SB. The issues and successful strategies reported in this feasibility study represent valuable information for planning future studies, and enhance recruitment and compliance with accelerometer protocols in SA and White British toddlers and parents

Reliability and validity of the early years physical activity questionnaire (EY-PAQ)

Measuring physical activity (PA) and sedentary time (ST) in young children (<5 years) is complex. Objective measures have high validity but require specialist expertise, are expensive, and can be burdensome for participants. A proxy-report instrument for young children that accurately measures PA and ST is needed. The aim of this study was to assess the reliability and validity of the Early Years Physical Activity Questionnaire (EY-PAQ). In a setting where English and Urdu are the predominant languages spoken by parents of young children, a sample of 196 parents and their young children (mean age 3.2 ± 0.8 years) from Bradford, UK took part in the study. A total of 156 (79.6%) questionnaires were completed in English and 40 (20.4%) were completed in transliterated Urdu. A total of 109 parents took part in the reliability aspect of the study, which involved completion of the EY-PAQ on two occasions (7.2 days apart; standard deviation (SD) = 1.1). All 196 participants took part in the validity aspect which involved comparison of EY-PAQ scores against accelerometry. Validty anaylsis used all data and data falling with specific MVPA and ST boundaries. Reliability was assessed using intra-class correlations (ICC) and validity by Bland–Altman plots and rank correlation coefficients. The test re-test reliability of the EY-PAQ was moderate for ST (ICC = 0.47) and fair for moderate-to-vigorous physical activity (MVPA)(ICC = 0.35). The EY-PAQ had poor agreement with accelerometer-determined ST (mean difference = −87.5 min·day−1) and good agreement for MVPA (mean difference = 7.1 min·day−1) limits of agreement were wide for all variables. The rank correlation coefficient was non-significant for ST (rho = 0.19) and significant for MVPA (rho = 0.30). The EY-PAQ has comparable validity and reliability to other PA self-report tools and is a promising population-based measure of young children’s habitual MVPA but not ST. In situations when objective methods are not possible for measurement of young children’s MVPA, the EY-PAQ may be a suitable alternative but only if boundaries are applied

ActivPAL-measured sitting levels and patterns in 9-10 year old children from a UK city.

Background: There is insufficient evidence of sitting time in UK children from validated objective measures. This study explored sitting patterns in primary school children from Bradford, UK, using the validated activPAL inclinometer. Methods: Overall, 79 children (9.8 (SD 0.3) years old, 52% boys; 70% South Asian) wore activPALs for 7 days. Total sitting time, sitting time accumulated in different bout lengths, and the proportion of wear time spent in these variables were explored and compared across different periods of the week. Results: Children spent 614 ± 112 (median ± IQR) min/day on school days and 690 ± 150 min/day on weekend days sitting. The proportion of time spent sitting was significantly higher on weekend days compared to school days (mean±SD: 74 ± 10% versus 68 ± 8%,P 30 min sitting bouts (mean±CI: 28 ± 27-33% versus 20 ± 20-22%, P 30 min) sitting bouts (mean±CI: 19 ± 16-22% versus 11 ± 10-14%, P < 0.001). Conclusions: Children spent large proportions of their waking day sitting, often accumulated in prolonged uninterrupted bouts and particularly after school and on weekends. Interventions to reduce sitting time in children are urgently needed

Reducing children's classroom sitting time using sit-to-stand desks: findings from pilot studies in UK and Australian primary schools.

BACKGROUND: This research examined the influence of sit-to-stand desks on classroom sitting time in primary school children. METHODS: Pilot controlled trials with similar intervention strategies were conducted in primary schools in Melbourne, Australia, and Bradford, UK. Sit-to-stand desks replaced all standard desks in the Australian intervention classroom. Six sit-to-stand desks replaced a bank of standard desks in the UK intervention classroom. Children were exposed to the sit-to-stand desks for 9-10 weeks. Control classrooms retained their normal seated desks. Classroom sitting time was measured at baseline and follow-up using the activPAL3 inclinometer. RESULTS: Thirty UK and 44 Australian children provided valid activPAL data at baseline and follow-up. The proportion of time spent sitting in class decreased significantly at follow-up in both intervention groups (UK: -9.8 ± 16.5% [-52.4 ± 66.6 min/day]; Australian: -9.4 ± 10% [-43.7 ± 29.9 min/day]). No significant changes in classroom sitting time were observed in the UK control group, while a significant reduction was observed in the Australian control group (-5.9 ± 11.7% [-28.2 ± 28.3 min/day]). CONCLUSIONS: Irrespective of implementation, incorporating sit-to-stand desks into classrooms appears to be an effective way of reducing classroom sitting in this diverse sample of children. Longer term efficacy trials are needed to determine effects on children's health and learning

Physical activity, sedentary time, and fatness in a biethnic sample of young children

Purpose: This study aimed to investigate associations of objectively measured physical activity (PA) and sedentary time with adiposity in a predominantly biethnic (South Asian and White British) sample of young children. Methods: The sample included 333 children age 11 months to 5 yr who provided 526 cross-sectional observations for PA and body composition. Total PA volume (vector magnitude counts per minute), daily time at multiple intensity levels (the cumulative time in activity 9500, 91000, 91500, I, 96000 counts per minute), and time spent sedentary (G820 counts per minute), in light PA (820–3907 counts per minute) and in moderate-to-vigorous PA (Q3908 counts per minute) were estimated with triaxial accelerometry. Indicators of adiposity included body mass index, waist circumference, and the sum of subscapular and triceps skinfold thicknesses. Statistical analyses were performed using multilevel regression and isotemporal substitution models adjusted for confounders. Effect modification by ethnicity was examined. Results: There was no evidence for effect modification by ethnicity (P interaction Q 0.13). In the whole sample, the accumulated time spent above 3500 counts per minute (i.e., high light-intensity PA) was inversely associated with the sum of skinfolds (A = j0.60 mm, 95% confidence interval [CI] = j1.19 to j0.021, per 20 minIdj1), and the magnitude of association increased dose dependently with PA intensity (peaking for time spent 96000 counts per minute = j1.57 mm, 95% CI = j3.01 to j0.12, per 20 minIdj1). The substitution of 20 minIdj1 of sedentary time with moderate-to-vigorous PA was associated with a lower sum of skinfolds (j0.77 mm, 95% CI = j1.46 to j0.084). Conclusions: High light-intensity PA appears to be beneficial for body composition in young South Asian and White British children, but higher-intensity PA is more advantageous

Calibration and validation of the ActiGraph GT3X+ in 2-3 year olds

Objectives: To calibrate and validate the ActiGraph GT3X+ to measure sedentary behaviour and physical activity in 2-3 year olds, using 5-s epochs; and to compare the predictive validity of the resulting cut-points with that of NHANES', Trost's, and Pate's 15-s cut-points. Design: Cross-sectional study. Methods: Eighteen children (2.86 ± 0.60 years) wore an ActiGraph GT3X+ during video-recorded semi-structured calibration activity sessions. Activity was coded following Children's Activity Rating Scale. Receiver Operating Characteristic analysis was used to derive Axis1 and vector magnitude cut-points for sedentary behaviour and moderate-to-vigorous physical activity at 5-s epochs. Agreement with Children's Activity Rating Scale was assessed with Cohen's kappa, Lin's concordance, and Bland-Altman plots. Predictive validity of all cut-points was assessed in an independent sample of 20 children (2.99 ± 0.48 years) video-recorded during free-play, using the same procedures as the calibration phase. Results: During calibration, vector magnitude cut-points (sedentary behaviour. ≤. 96.12. counts; moderate-to-vigorous physical activity. ≥. 361.94. counts) showed slightly better classification agreement with Children's Activity Rating Scale than Axis1 cut-points (sedentary behaviour. ≤. 5. counts; moderate-to-vigorous physical activity. ≥. 165. counts), but the latter showed the lowest bias in estimated sedentary behaviour and moderate-to-vigorous physical activity time. In the validation sample, 5-s Axis1 cut-points showed the best predictive validity and lowest mean differences of all cut-points between predicted and observed sedentary behaviour (-2.31%), light physical activity (-24.40%), and total physical activity time (-0.95%). Moderate-to-vigorous physical activity time was significantly overestimated by all cut-points (128.33-184.17%). Conclusions: Because moderate-to-vigorous physical activity was highly overestimated, using only the 5-s Axis1 sedentary behaviour cut-point to distinguish sedentary behaviour from total physical activity is advised. The high accuracy indicates that these cut-points are useful for epidemiological studies involving the sedentary behaviour and physical activity of 2-3 year olds

Qualitative feasibility of using three accelerometers with 2-3-year-old children and both parents

This study assessed mothers' opinions about the feasibility and acceptability of using the ActiGraph GT3X+, Actiheart, and activPAL3 with their 2- to 3-year-old children, as well as with themselves and their husbands/partners, for an 8-day period. Method: Six focus groups were run with Pakistani and White British mothers (n = 17), in English or Urdu, at Children's Centers in Bradford, United Kingdom. Each accelerometer was shown to the mothers while its characteristics and wearing procedures were explained. Mothers were then asked about their opinion on the feasibility of use with their toddlers, themselves, and husbands/partners, as well as their monitor preference. Data were transcribed verbatim and analyzed through thematic analysis. Results: The ActiGraph was the most preferred accelerometer for use with children, while the Actiheart was the least favorable. The ActiGraph was also the most preferred accelerometer for use with both mothers and fathers. Main issues raised included unsuitability of the Actiheart for fathers due to chest hair, discomfort due to the large size of the activPAL3 in relation to children's thighs, and children pulling off the Actiheart or tampering with the device if its presence was noticed (ActiGraph/Actiheart). Conclusion: The most preferred/accepted accelerometer overall was the ActiGraph GT3X+ for both children and parents. Issues raised with the devices have potential to impact recruitment and compliance rates of studies targeting this population, which highlights the importance of assessing the feasibility/acceptability of different devices with the target population ahead of planning research involving physical activity measurement