Table 2.
Determinants of outdoor time in children and youth.
| Author (Year) | Potential Determinants Examined | Main Results |
|---|---|---|
| Studies Beginning in Early Childhood (<5 Years) | ||
| Arcury (2017) [34] | Gender, age, people per bedroom, number of inappropriate media (having a TV in view at meals and having a TV in the child’s bedroom), number of age-appropriate toys, limiting screen time, frequency of visits to play spaces | Compared to baseline, the mean time mothers estimated their child playing in the yard or park was 29.9 min/day greater at year 1 and 20.1 min/day greater at year 2 (both p = 0.001). For each additional month of age at baseline (B = 1.0 min/day, p = 0.049) and each age-appropriate toy (B = 12.3, p = 0.001), children spent more time playing in the yard or park. Each unit increase in the limiting screen time score was associated with less OP: B = −6.4, p = 0.016. |
| Cameron (2019) [35] | Influence of peer groups (i.e., partner, friends, mothers’ group, and family) on child’s nutrition, TV time, and PA | No association between influence of any peer group and time spent outside (all p > 0.05). |
| Davison (2011) [36] | Exposure to community guide and group sessions | Odds of playing outdoors > 60 min per day for the intervention site at follow-up compared to baseline was OR = 1.68 (95% CI = 1.19–2.37, p = 0.003). The adjusted OR for the intervention site at follow-up vs. comparison sites was 2.79 (95% CI = 1.94–4.02, p < 0.001). |
| Essery (2008) [37] | Effect of newsletter or booklet intervention on child feeding practices and physical activity | There was a significant increase in OP reported by the newsletter (p < 0.01) and booklet (p < 0.01) groups between baseline and post-test. |
| Händel (2017) [38] | Healthy Start Intervention, focused on changing diet, PA, sleep, and stress management | Participants in the intervention group spent more time on sports and outdoor activities combined at follow-up (intervention: 400 min/wk (95% CI: 341, 459) vs. control group: 321 min/wk (95% CI: 277, 366); p = 0.02). OP did not differ between groups post-intervention (intervention: 316 min/wk (95% CI: 264, 368) vs. 265 (95% CI: 209, 321); p = 0.19). |
| Hesketh (2015) [39] | Age, child sex, and mother’s education | OT increased from 25.7 to 90.0 min/day from 4 to 20 months of age (p < 0.001). Children of university-educated mothers engaged in more OT at all 3 time points (all p < 0.05). |
| Hnatiuk (2013) [40] | Age | Outdoor time increased from 46.93 ± 46.64 to 61.10 ± 48.35 min/week (p < 0.001). |
| Honda-Barros (2019) [41] | Age, gender, maternal education, school type (private vs. public), school shift (afternoon vs. morning), parent participation in PA with children, excess weight, and OP at baseline | Children who participated in PA with their parents were more likely to spend ≥60 min/day in OP (OR = 1.79; 95% CI = 1.27–2.54, p < 0.01). Children who spent ≥ 60 min/day in OP at baseline were more likely to maintain this behaviour after reaching school age (OR = 1.45; 95% CI = 1.02–2.07; p = 0.04). Children with excess weight at baseline engaged in less OP (OR = 0.56; 95% CI = 0.39–0.80; p < 0.01). |
| Huang (2021) [42] | Age | Over 2 years, the proportion of children who played outdoors ≥ 7 times a week decreased from 67.4 to 62.1%, and the proportion who played outdoors ≥ 60 min decreased from 53.3 to 38.8% (both p < 0.001). |
| Li (2022) [43] | Age, child sex, household size and income, pregnancy depression score, screen use, phone use, maternal and parental age, race, education level, and occupation | OT varied significantly with age (p < 0.001), with an increase from 12 to 18 months followed by a gradual decrease. Children from older and more educated fathers had an increase in OT over time (p < 0.05). |
| Lumeng (2017) [44] | Exposure to 1 of 3 interventions: (1) Head Start program + Preschool Obesity Prevention Series (targeting obesity prevention behaviours) + Incredible Years Series (IYS) (program to improve children’s self-regulation); (2) Head Start + Preschool Obesity Prevention Series; or (3) Head Start only | There were no differences in OT between children assigned to different interventions (intervention 2 vs. 3: change from baseline = −0.08 h/day, p = 0.48; intervention 1 vs. 3: change from baseline = 0.12 h/day, p = 0.25; intervention 2 vs. 1: change from baseline = 0.19 h/day, p = 0.06). |
| Sääkslahti (2004) [45] | Age, season, and exposure to intervention (parents of children in the intervention group received information and concrete suggestions on how, when, and where to encourage their child’s PA) | OP varied with intervention (p = 0.041), age (p = 0.016), and season (=12.72, p < 0.001). There were also combined relationships with age and season (p < 0.001), as well as intervention, age, and season (p < 0.001). The age-dependent increase was stronger in the intervention group. Children in the intervention group played more outdoors (p = 0.041) and less indoors (p = 0.049) than controls. |
| Shah (2017) [46] | Age, gender, future likely myopia, and number of myopic parents | Girls spent less time outdoors than boys (β = −0.04), but the difference was not significant (p = 0.14). Through the study period, children with one or two myopic parents spent an average of ~0.1 SD units per day less time outdoor than children whose parents were both non-myopic (p < 0.01). OT decreased with age, but the difference was not significant (β = 0.007; p = 0.073). |
| Tandon (2019) [47] | Exposure to interventions (Active Play! and Outdoor Play!) | In the preschool childcare centres receiving the Active Play! intervention, increases in outdoor child-initiated activity (18.8 min/day; 95% CI: 12.6, 25.0; p < 0.001), teacher-led activity (2.5 min/day; 0.1, 4.9; p = 0.04), and total OT (21.4 min/day; 14.6, 28.3; p < 0.001) were found. In the Outdoor Play! intervention group, OT increased by 24 min/day (95% CI: 19.3, 28.6; p < 0.001). Outdoor child-initiated activity increased (23.8 min/day; 19.1, 28.4), and outdoor teacher-initiated activity did not change significantly. The only significant post-intervention difference between interventions favoured Active Play! and was for outdoor teacher-led time (2.6 min/day; 4.5, 0.7; p = 0.008). |
| Thiering (2016) [48] | Birth in a rural (Wesel) vs. urban area (Munich) | Adolescents born in Wesel spent more time outside in the summer than those in Munich (χ2 = 46.94; p < 0.00001) a based on the frequencies reported in Table 1. |
| Xu (2016) [49] | Age, sleep patterns (bedtime, sleep duration, sleep latency, sleep time > 10 h/day, and waking at night) | Over time, there was an increase in children’s mean OP time (p < 0.0001). |
| Studies beginning in childhood (5–11 years) | ||
| Avol (1998) [50] | Gender and ambient ozone concentration | On average, boys spent ~37 min longer outside in the spring than girls (p < 0.001) and ~22 min more outside in the summer (p = 0.04). |
| Bacha (2010) [51] | Parent-perceived neighbourhood safety (classified in tertiles) | No difference in OT between tertiles of parent-perceived neighbourhood safety (p = 0.90). |
| Bagordo (2017) [52] | Season, parental education, and father’s occupational level | 70.3% of children played outdoors for >1 h/day at follow-up (spring) vs. 33% at baseline (winter) (p < 0.001). Children whose parents had <26 combined years of education were more likely (59.7% vs. 48.7%) to engage in >1 h/day of OP (p < 0.001). Children whose fathers had level III or IV occupations (service worker or unemployed, respectively) were more likely (57.4% vs. 48.1%) to engage in >1 h/day of OP (p < 0.001). |
| Buller (2020) [53] | Exposure to intervention on sun safety | In schools where principals implemented sun safety practices, parents reported that children spent less time outdoors between 10 am and 4 pm over one week (mean = 14.78 vs. 16.32 h; p = 0.033). |
| Christiana (2017) [54] | Exposure to outdoor PA prescription intervention and season | No difference in frequency of OT between groups and frequency of achieving ≥60 min of outdoor PA (p ≥ 0.29). OT declined from baseline (August) to follow-up (November/December; p < 0.01); authors attributed this finding to seasonality. |
| Cleland (2008) [55] | Seasons, age, and gender | OT was higher during warmer vs. cooler months at Time 1 and Time 2 (p < 0.01). OT was higher in older boys vs. older girls in both seasons at both time points. OT during warmer months declined between Time 1 and 2 among older boys (p < 0.01), OT on weekends in the warmer months declined among older girls (p < 0.01), and OT on weekdays in the colder months increased among older girls (p < 0.01). |
| Cleland (2010) [56] | Outdoor tendencies, indoor tendencies, parental encouragement, social opportunities, rules and restrictions, parental belief that child must be supervised when playing outside, parent report that there are no adults to supervise child while playing outside after school, dog ownership, number of siblings, yard size, home PA opportunities, access to local destinations, and weather as barrier (individual items: cold/dark in the winter; heat in the summer) | For younger boys, “high” indoor tendencies were associated with less OT (−168 min/wk; 95% CI = −324, −13), while “high” social opportunities were associated with more OT over 5 years (170 min/wk; 95% CI = 26, 314). Among older boys, higher indoor tendencies (“medium”: −215 min/wk; 95% CI = −311, −119; “high”: −324; 95% CI = −472, −176) and a lack of adult supervision (−47 min/wk; 95% CI = −91, −3) were associated with less OT, while “high” outdoor tendencies were associated with more OT over 5 years (123 min/wk; 95% CI = 40, 207). Among younger girls, higher indoor tendencies were associated with less OT (“medium”: −188 min/wk; 95% CI = −356, −21; “high”: −247 min/wk; 95% CI = −374, −120), while “high” parental encouragement was associated with more OT over 5 years (234 min/wk; 95% CI = 30, 438). Among older girls, “medium” outdoor tendencies (200 min/wk; 95% CI = 27, 374) and “high” parental encouragement were associated with more OT (151 min/wk; 95% CI = 67, 236), while a lack of adult supervision was associated with less OT (−34 min/wk; 95% CI= −60, −9). |
| Cortinez-O’Ryan (2017) [57] | Exposure to an evening street closure intervention (twice a week for 12 weeks) | There were significant increases in median number of weekdays with OP (from 2 to 3; p < 0.01), after-school OP time (from 60 to 90 min; p = 0.02), and weekly after-school OP time in the experimental neighbourhood (from 120 to 300; p = 0.01). No changes were observed in the control neighbourhood. |
| Flynn (2017) [58] | Exposure to intervention: family resource workbook and 3 group sessions | During the program, families increased their time spent being active together by an average of 111 min/week above baseline. Outdoor PA time was higher than baseline in 3 out of 4 weeks (p < 0.05). Mean length of a family outdoor PA bout was significantly greater than at baseline for all 4 weeks of the program. Families increased the mean length of their family outdoor PA bouts by ~41 min/bout. Frequency of family outdoor PA bouts did not change significantly. |
| Ford (2002) [59] | Behavioural vs. counselling (control) intervention to reduce children’s television viewing | Compared to the control group, the behavioural intervention led to a medium-to-large increase in OT (change of 1.0 ± 5.9 vs. −4.7 ± 9.4 h/wk; Cohen’s d = 0.71); however, this difference was not statistically significant (p = 0.057). |
| Gerards (2015) [60] | Exposure to the “Lifestyle Triple P” intervention | The increase in OT between baseline and first follow-up (4 months) was not significant (B = 2.85; 95% CI= −0.16, 5.86; p = 0.063; Cohen’s d = 0.56). Significant increase was found at the final (12 month) follow-up (B = 1.94; 95% CI = 0.04, 3.84; p < 0.05; Cohen’s d = 0.55). |
| Handy (2008) [61] | Parental preference for and perceptions of neighbourhood characteristics ((1) nearby amenities; (2) neighbourhood upkeep; (3) large back yard; (4) large front yard; (5) living in a cul-de-sac rather than on a through street; (6) low traffic on neighbourhood streets; (7) parks and open spaces nearby; (8) sidewalks through neighbourhood; (9) lots of interaction among neighbours; (10) lots of people out and about in the neighbourhood; (11) low crime rate in neighbourhood; (12) safe neighbourhood for children to play). Perceived changes in abovementioned characteristics, age of children in the household, parental education, household income, changes in household size, changes in number of children in household, changes in income, type of housing (apartment vs. other) suburban vs. traditional neighbourhood | After residential relocation, 52.7% of parents reported no change in OP frequency, 15.7% reported a decline, and 31.5% reported an increase. Preference for a safe neighbourhood for kids to play was associated with more OP (β = 0.147; p = 0.028). Changes in 4 perceived neighbourhood characteristics were also associated with more OP: cul-de-sac interacted with the presence of children ages 6–12 years (β = 0.170 p = 0.014), large front yards (β = 0.200; p = 0.005), low crime (β = 0.290; p = 0.002), and interaction among neighbors (β = 0.189; p = 0.008). Parents with children aged 12–16 were more likely to report no change in OP vs. those with younger children. Households with children aged 5–12 were more likely to report an increase in OP (β = 0.234; p = 0.001) than households with older children. |
| He (2015) [12] | Exposure to outdoor play intervention (additional outdoor activity class; 40 min/school day) | No difference in OT between children in intervention and control schools at baseline and 1-, 2-, and 3-year follow-ups (all p > 0.20). |
| Kemp (2022) [62] | Age | Time spent in “other outdoor/nature activities” (the time use category that included OT) did not change with age (all p > 0.05). |
| Li (2021) [63] | COVID-19 (number of days/week that children practised 4 preventive public health measures) | For each additional day/week that children adhered to public health measures, OT decreased by 17.2 min/day in the unadjusted model (95% CI = −22.07, −12.40; p < 0.001) and by 12.5 min/day in the adjusted model (95% CI = −18.25, −6.79; p < 0.001). Adherence to each individual measure was associated with less OT in both the unadjusted and adjusted models (p < 0.05), except for limiting the number of visitors. |
| Milne (2000) [64] | Exposure to school-based multicomponent intervention with specially designed curriculum (“medium” intervention) vs. exposure to multicomponent intervention plus program materials over the summer holidays and low-cost sun-protective swimwear (“high” intervention) compared to standard health curriculum (“control”) | Adjusted mean OT during the summer holidays between 11 am and 2 pm was highest in the control group (28.4 h) vs. the high intervention group (22.3 h) and the moderate group (24.1 h) (p = 0.01). Children in the moderate group tended to spend less time outside in both periods. Adjusted mean OT between 8 am and 4 pm was 111 h for the control group (95% CI: 103.9, 118.5), 113 h for the moderate group (104.6, 121.6), and 108.7 h for the high group (99.4, 118.5), with no differences between groups (p = 0.8). |
| Milne (2007) [65] | School-based sun protection curriculum over 4 years; children were encouraged to reduce sun exposure by staying indoors during the middle of the day, when solar ultraviolet radiation is highest, and to protect themselves when outdoors by using shade, clothing, hats, and sunscreen | The median OT in each group (control, “moderate” intervention, and “high” intervention) was similar after 2 years. There was no association between study group and total OT at either age 10 or age 12. |
| Nigg (2021) [66] | Age, OP (past behaviour), MVPA, TV, and computer/gaming time in previous survey waves | OP decreased from 5.93 ± 1.43 days/week at Time 1 to 1.14 ± 1.85 days/week at Time 3. OP at Time 1 was associated with more OP at Time 2, which was positively associated with OP at Time 3 (p < 0.05). |
| Ngo (2009) [67] | Exposure to intervention: structured weekend outdoor activities and incentives for children to increase their daily steps via pedometers | At the 6-month follow-up, a mean of 14.75 h/wk of OT was reported in the questionnaire for the intervention group vs. 12.40 h/wk for the control group (p = 0.04). At the 9-month follow-up, parents in the intervention and control groups reported 15.95 vs. 14.34 h/wk outdoors (p = 0.29). Mean OT from the diary was 6.98 h/wk and 7.93 h/wk for the control and intervention groups, respectively (p = 0.12). |
| Nordvall-Lassen (2018) [68] | “Moderate” preterm (32–36 weeks of gestation) vs. term birth | No difference in odds of reporting different weekly durations of OT based on birth status (OR for 4–6 h = 1.13 (95% CI = 0.59–1.74), OR for 7–13 h = 1.14 (0.61–1.70), OR for 14–20 h = 1.15 (0.52–1.67), and OR for 21–60 h = 1.20 (0.35–2.22)). |
| Ostrin (2018) [69] | Seasons (spring, summer, and fall) and parental outdoor time | Children were more exposed to outdoor light (lux) in the summer (110.5 ± 45.8 min/day) vs. spring (94.2 ± 30.4 min/day) or fall (72.2 ± 31.0 min/day, p < 0.0001). Children received the highest mean daily light exposure during the summer vs. spring and fall seasons (p < 0.0001). Parent and child OT were significantly correlated (r = 0.76, p = 0.0002). |
| Remmers (2014a) [70] | Gender, age, and parental and environmental factors, including accessibility of PA-related places, attitude towards child PA, concern regarding child PA, restriction of screen time, social capital, functionality, traffic safety, attractiveness, perceived responsibility, pressure, and monitoring | Children spent on average ~60 more minutes in OP per week at 7 vs. 5 years of age (both boys and girls) (p < 0.01). At both time points, boys spent significantly more time in OP than girls (p < 0.01), and there were significant differences in OP duration between all seasons (p < 0.01; but season was examined as a random effect, and the direction of association was not reported). Significant regression coefficients (β) for parental factors were accessibility of PA-related places within 10 min walking distance of home with 0.05 (95% CI = 0.01, 0.09), positive parental attitude towards child PA with 0.09 (0.05, 0.13), concern regarding child PA with −0.04 (−0.09, −0.001), restriction of screen time with −0.21 (−0.26, −0.17), and social capital with 0.07 (0.03, 0.11). |
| Remmers (2014b) [71] | Socio-demographic characteristics (child age, gender, ethnicity, and BMI and parental age, ethnicity, BMI, and education), family environment (parental attitude, family attitude, perceived difficulty, habit strength and intention to improve OP, presence of rules, presence of monitoring, presence of active encouragement, and child autonomy), and parent-perceived physical environment (safety perception during daytime and evenings, friendliness for children, attractiveness for children, and safety of OP without supervision) | Parents with high vs. low education reported that their child played outside 28.40 min/day less (95% CI = −55.66, −1.14) at age 7. Parents who indicated difficulty towards improving OP reported 22.11 (−33.41, −10.81) less minutes of OP. Parents with a habit towards improving OP (23.99; 95% CI = 14.61, 33.61), the presence of rules regarding OP (16.46; 95% CI = 9.26 to 23.67), and modelling from the respondent’s partner (1.85; 95% CI = 0.27, 3.42) were associated with more min/day of OP. Parental active encouragement of OP at baseline was associated with 8.91 (−17.33 to −0.48) less minutes of OP at age 7. Higher child age was related to more OP at baseline, but this attenuated significantly over time (p[interaction] < 0.01). |
| Sadeh-Sharvit (2020) [72] | Exposure to intervention (online 6-session parent-based prevention program after bariatric surgery) | Children spent less time outdoors at follow-up as reported by parents with bariatric surgery (baseline: 125.63 (58.88) min/day; follow-up: 103.00 (61.40); Hedges’ g = 0.36 (−0.64, 1.35)) or partners (baseline: 102.86 (58.71) min/day; follow-up: 97.50 (102.10); Hedges’ g = 0.06 (−1.05, 1.18)). As 95% CIs cross 0, differences were not significant. |
| Sanchez-Tocino (2019) [73] | Age and gender | There were no significant differences in hours spent on outdoors activities by age or gender (p > 0.05). |
| Schneor (2021) [74] | COVID-19 restrictions | Daily OT decreased from 1.8 ± 1.0 h to 0.7 ± 0.7 h (p = 0.001). In the subsample followed up after restrictions were removed, OT returned to pre-pandemic levels (1.8 ± 0.8 h). |
| Shepherd-Baniga (2014) [75] | Farmworker vs. non-farmworker status and agricultural seasons (thinning vs. pre-thinning) | Children spend 9 h/wk more outside during the thinning (summer) vs. pre-thinning season (spring) (95% CI: −13.0, −5.1, p < 0.001). In the thinning season, mean OT was 30.2 ± 20.8 h/wk for farmworker children vs. 24.2 ± 16.7 h/wk for non-farmworker children (p = 0.004). |
| Sum (2022) [76] | COVID-19 restrictions and household income | 64.1% of parents reported significant decreases in OP or exercise due to the COVID-19 lockdown (p < 0.001). Each 1,000-Singapore-dollar decrease in income before the lockdown was associated with higher odds of reporting the elimination of all OP or exercise (OR = 1.09; 95% CI = 1.01, 1.19; p = 0.03). |
| Van Griecken (2014) [77] | Exposure to a healthy lifestyle counselling intervention to parents of overweight 5-year-olds | Proportion of children playing outside ≥ 1 h/day decreased in the intervention (93.3 to 77.1%; p < 0.001) and control groups (94.3 to 77.1%; p < 0.001), with no difference between groups (OR = 1.11; 95% CI = 0.60, 2.06). There was no significant difference in OP, expressed in min/day, at follow-up (β = 8.22; 95% CI = −15.77, 32.22) between groups. |
| Van Stralen (2012) [78] | Exposure to JUMP-in school-based intervention targeting sports participation and outdoor play. Also examined the effect of OP at baseline and child-perceived pros and cons, social pressure, social support, social modelling, self-efficacy, planning skills, barriers, enjoyment, and habit strength related to OP | No significant intervention effect in the weekly frequency of OP (B= −0.30; 95% CI= −0.79, 0.19). Significant positive associations were found between social support (b = 0.04; 95% CI: 0.01–0.08), self-efficacy (b = 0.15; 95% CI: 0.00–0.30), enjoyment (b = 0.21; 95% CI: 0.14–0.28), and habit strength (b = 0.38; 95% CI: 0.18–0.58) and OP. In their Figure 3, the authors show that OP at Time 1 (b = 0.17) and planning skills (b = 0.15) were significantly associated with more OP at Time 2 (but did not provide the p-value). |
| Walker (2021) [79] | Participation in a child-centred play therapy intervention | There were no differences in OT on weekdays and weekend days between baseline and the end of the intervention (all p > 0.20) |
| Wolters (2022) [80] | Age | OT was higher at baseline vs. the last follow-up: 2.41 ± 1.39 vs. 1.80 ± 1.29 h/day (t = 13.63; p < 0.0001 based on the values reported in Table 2) b |
| Studies beginning in adolescence (12–17 years) | ||
| Dunton (2007) [81] | Gender, age, time of week, and season | Compared with girls, boys were more likely to report exercising in outdoor settings (p = 0.002) and walking in outdoor settings (p < 0.001). Walking in an outdoor setting decreased during high school (7% per year, p = 0.019), but outdoor exercising did not (p = 0.189). Students were more likely to exercise or walk outdoors on weekend days vs. weekdays (p < 0.001). Students were more likely to walk or exercise outdoors in the fall and spring seasons vs. the winter (all p < 0.05) and to walk outdoors in the spring vs. fall season (p = 0.010). |
| Evenson (2018) [82] | Age | The number of park visits identified by GPS during the 6-day monitoring period increased from 73 to 83 (p < 0.02). Mean duration of park visits decreased from 63.9 to 38.4 min (p < 0.03). |
| French (2013) [83] | Age, ethnicity, and gender | In the young cohort, OT decreased by just over 1 h/wk from baseline to follow-up, accompanied by a decline in outdoor leisure (both p ≤ 0.001). Time spent on organized outdoor sports increased (p < 0.0001). In the older cohort, there was a significant decrease in OT and outdoor sporting activities (p < 0.0001), but not in outdoor leisure time (p = 0.06). Boys spent ~2.5 h/wk more outdoors than girls in both cohorts at baseline and follow-up (all p < 0.0001). The decrease in OT between baseline and follow-up was significant for girls in both cohorts (younger, p = 0.006; older p < 0.0001) and for boys in the older cohort (p = 0.001), but not in the younger cohort (p = 0.052). The decline in OT with age was seen in European Caucasian participants (younger cohort: p = 0.001; older cohort: p < 0.0001), but not in East Asian participants (younger cohort: p = 0.7; older cohort: p = 0.07). |
| Gopinath (2013) [84] | Birth weight (categorized in quartiles) | In 12-year-olds, an increase in outdoor PA (~1 h/wk) was observed with increasing birth weight after adjustment for covariates (from the lowest to highest quartile; ptrend = 0.02). Among 17- to 18-year-olds, higher birth weight was associated with higher outdoor PA (~1 h/wk, p = 0.04). In multivariable models, each SD (573.5 g) increase in birth weight was associated with a 15 min/wk increase in outdoor PA (p = 0.01). Twelve-year-olds in the high- vs. very-low-birth-weight group (>4000 vs. <2000 g) spent ~1.3 h/wk more in outdoor PA (ptrend = 0.02). |
| Lin (2017) [85] | Age and gender | Among all students combined, there was a decrease in leisure OT (8.5 ± 7.7 vs. 9.9 ± 7.0 h/wk, p = 0.02). For primary students, there was an increase in outdoor sports time (3.5 ± 4.3 vs. 2.4 ± 3.0 h/wk, p = 0.02). For secondary students, there was a non-significant decrease in total OT (10.9 ± 8.8 vs. 12.7 ± 9.8 h/wk, p = 0.09). Girls spent less time outdoors than boys (baseline: 11.9 ± 7.9 vs. 14.4 ± 9.5 h/wk, p = 0.03; follow-up: 10.5 ± 8.2 vs. 13.9 ± 9.6 h/wk, p = 0.005) and less time in outdoor sports (baseline: 2.4 ± 2.8 vs. 4.0 ± 5.2 h/wk, p = 0.006; follow-up: 2.3 ± 3.1 vs. 5.1 ± 5.0 h/wk, p < 0.001). |
| Miller (2017) [86] | Parental perceptions of neighbourhood danger, perceived neighbourhood support, parental monitoring (in general), and OT at baseline | There was a positive correlation between the percent time spent outside at Times 1 and 2 (r = 0.480). Increased levels of parental monitoring at Time 1 was associated with increased OT at Time 2 (coeff = 0.7508, p = 0.0109). |
| Watowicz (2012) [87] | Recent parental weight loss surgery | Control group participants were significantly more likely than those whose parents underwent weight loss surgery to report ≥1 h/day of OP (55.8 vs. 31.6%, p = 0.01). |
Note: When potential determinants are not mentioned in the third column, this means that they were not significantly associated with outdoor time. B = unstandardized regression coefficient; β = standardized regression coefficient; CI = confidence interval; coeff = coefficient; OP = outdoor play; OR = odds ratio; OT = outdoor time; PA = physical activity; SE = standard error. a Chi-square test performed by the review team based on reported frequencies using an online calculator (https://www.socscistatistics.com/tests/chisquare2/default2.aspx, accessed on 1 December 2022). b t-test performed by the review team based on reported means and standard deviations using an online calculator (https://www.graphpad.com/quickcalcs/ttest1/, accessed on 1 December 2022).