PT  - JOURNAL ARTICLE
AU  - Fraysse, François
AU  - Grobler, Anneke C
AU  - Muller, Josh
AU  - Wake, Melissa
AU  - Olds, Timothy
TI  - Physical activity and sedentary activity: population epidemiology and concordance in Australian children aged 11–12 years and their parents
AID  - 10.1136/bmjopen-2018-023194
DP  - 2019 Jul 01
TA  - BMJ Open
PG  - 136--146
VI  - 9
IP  - Suppl 3
4099  - http://bmjopen.bmj.com/content/9/Suppl_3/136.short
4100  - http://bmjopen.bmj.com/content/9/Suppl_3/136.full
SO  - BMJ Open2019 Jul 01; 9
AB  - Objectives To describe the epidemiology and parent–child concordance of objectively measured physical activity in a population-based sample of Australian parent–child dyads.Design Cross-sectional study (Child Health CheckPoint) nested within the Longitudinal Study of Australian Children.Setting Assessment centres in seven Australian cities and eight regional towns or home visits; February 2015–March 2016.Participants Of all CheckPoint families (n=1874), 1261 children (50% girls) and 1358 parent (88% mothers) provided objectively measured activity data, comprising 1077 parent–child dyads.Outcome measures Activity behaviour was assessed by GENEActiv accelerometer. Duration of moderate-to-vigorous physical activity (MVPA) and vigorous physical activity and sedentary behaviour (SB) were derived using Cobra custom software, along with MVPA/SB fragmentation and mean daily activity. Pearson’s correlation coefficients and linear regression estimated parent–child concordance. Survey weights and methods accounted for the complex sample design and clustering.Results Although parents had average lower accelerometry counts than children (mean [SD] 209 [46] vs 284 [71] g.min), 93% of parents met MVPA daily duration guidelines on published cutpoints (mean [SD] 125 [63] min/day MVPA), compared with only 15% of children (mean 32 [27] min). Parents showed less daily SB duration (parents: 540 [101], children: 681 [69] minutes) and less fragmented accumulation of MVPA (parents: α=1.85, children: α=2.00). Parent–child correlation coefficients were 0.16 (95% CI 0.11 to 0.22) for MVPA duration, 0.10 (95% CI 0.04 to 0.16) for MVPA fragmentation, 0.16 (95% CI 0.11 to 0.22) for SB duration and 0.18 (95% CI 0.12 to 0.23) for SB fragmentation.Conclusions Standardised cutpoints are needed for objective activity measures to inform activity guidelines across the lifecourse. This may reflect large amounts of time in non-shared environments (school and work).