Table 1.
Description of correlates included at each time point
| Variable | Description and/or coding | Child aged 4 months Mean (SD) or tertile cut-points |
Child aged 9 months Mean (SD) or tertile cut-points |
Child aged 19 months Mean (SD) or tertile cut-points |
Child aged 3.5 yearsa Mean (SD) or tertile cut-points |
|---|---|---|---|---|---|
| Child behaviours | |||||
| Time spent being physically active with mum | Proxy-report of the amount of time in the last week. Due to distribution of the data, divided into tertiles (low, medium, high). |
Low = 0–26 Med = 29–60 High = 64–428 |
Low = 0–34 Med = 39–86 High = 94–600 |
Low = 0–60 Med = 69–120 High = 150–360 |
Low = 0–420 Med = 435–480 High = 870–2820 |
| Time spent having tummy time | Proxy-report of the amount of time in the last week. Due to distribution of the data, divided into tertiles (low, medium, high). |
Low = 0–9 Med = 10–26 High = 30–257 |
N/A | N/A | N/A |
| Time spent on the floor (T1 & T2); Time spent ‘free to move around’ (T3 & T4) | Proxy-report of the amount of time in the last week. Due to distribution of the data, divided into tertiles (low, medium, high). |
Low = 0–34 Med = 35–90 High = 94–428 |
Low = 4–120 Med = 129–240 High = 257–600 |
Low = 60–360 Med = 390–480 High = 510–1440 |
Low = 0–3360 Med = 3480–4620 High = 4680–5880 |
| Time spent with other children of a similar age | Proxy-report of the amount of time in the last week. Due to distribution of the data, divided into tertiles (low, medium, high). |
Low = 0–13 Med = 15–17 High = 19–480 |
Low = 0–17 Med = 20–34 High = 39–1371 |
Low = 0–30 Med = 60–90 High = 120–1440 |
Low = 0–600 Med = 630–1680 High = 1740–5400 |
| Time spent with older children | Proxy-report of the amount of time in the last week. Due to distribution of the data, divided into tertiles (low, medium, high). |
Low = 0–0 Med = 1–17 High = 26–343 |
Low = 0–9 Med = 17–26 High = 34–343 |
Low = 0–0 Med = 10–30 High = 60–600 |
Low = 0–0 Med = 50–420 High = 465–5580 |
| Time spent outside | Proxy-report of the amount of time in the last week. Due to distribution of the data, divided into tertiles (low, medium, high). |
Low = 0–17 Med = 19–43 High = 51–275 |
Low = 0–30 Med = 34–69 High = 77–257 |
Low = 0–60 Med = 90–120 High = 150–480 |
Low = 0–810 Med = 840–1260 High = 1320–2850 |
| Organised activity | One item assessing children’s participation in an organised activity (Yes/No) | N/A | N/A |
Yes = 49.0% No = 51.0% |
Yes = 79.5% No = 20.5% |
| Maternal beliefs | |||||
| Maternal physical activity knowledgeb | Composite score (scale 0–3) of tenc questions examining the importance of physical activity for children’s health and development | 2.51 (0.34) | N/A | 2.54 (0.35) | 2.46 (0.32) |
| Maternal physical activity viewsb | Composite score (scale 0–3) of four questions assessing mothers’ views of physically active children | 0.88 (0.43) | N/A | 0.73 (0.44) | 1.85 (0.45) |
| Maternal physical activity optimismb | Composite score (scale 0–3) of 3 questions examining the anticipated ease of engaging children in physical activity | 2.32 (0.44) | 2.48 (0.47) | 2.39 (0.45) | 2.31 (0.51) |
| Maternal physical activity self-efficacyb | Composite score (scale 0–3) of 3 questions examining mothers’ confidence for promoting physical activity | 2.49 (0.48) | 2.57 (0.47) | 2.51 (0.49) | 2.36 (0.52) |
| Maternal floor concernsb | Composite score (scale 0–3) of two questions examining perceptions of safety of floor play | 0.93 (0.54) | N/A | N/A | N/A |
| Parental behaviours | |||||
| Parental facilitation of physical activity | Summed score of questions on parental facilitation of physical activity for children (1 Never or rarely, 2 Some days each week, 3 Most days each week, 4 Every day, 5 At least once a day, 6 Several times each day), converted into weekly equivalent scoresd | 23.84 (5.76) | 24.36 (5.70) | 40.87 (12.75) | 50.05 (10.12) |
| Maternal physical activity | Mothers self-reported using the Active Australia Survey. Reported in minutes per past week. | 466.07 (355.78) | 486.35 (368.42) | 396.29 (375.29) | 398.68 (340. 72) |
| Home environment | |||||
| Physical activity equipment in home |
T1-T3: Number of age-appropriate equipment items for young children parents’ anticipate they will provide in their homeb T4: How frequently child uses age-appropriate equipment items in their home (1 Don’t have, 2 Never/rarely, 3 Less than once per week, 4 1–2 times per week, 5 3–4 times per week, 6 5–6 times per week, 7 Daily). Items at T4 were: Balls, bats/rackets, bike/ride on, climbing equipment, trampoline, swings/slides, swimming pool, skipping rope, scooter, other toys that encourage active play. |
6.53 (2.16) | 5.76 (1.18) | 8.66 (1.90) | 35.03 (9.27) |
aT4 tertiles were capped as follows: time spent with other children/older children and time spent free to move about capped at 14 h per day (mean waking time for child of this age); time outdoors and time spent being physically active with mum capped at 7 h/day (half of waking day)
bPlease refer to Hnatiuk et al., 2013 for further processing details
cAt T4, two items within this scale were dropped as they were no longer relevant due to the age of the child
dThis measure consisted of n = 2 items at T1 and T2, n = 6 items at T3 and n = 7 items at T4