Publications

Accurate assessment of physical activity (PA) in children and adolescents is required to establish PA levels, monitor changes and inform public healthy policy. This study systematically reviews the literature to determine the extent of agreement between indirect (e.g., questionnaire) and direct (e.g., accelerometry) assessments of PA in pediatric populations (<or=19 years).Literature was identified through searching electronic databases (e.g., MEDLINE, EMBASE), websites of relevant organizations and conference abstracts until April 2007. Studies were included if they collected indirect and direct measures of PA in pediatric populations and were reported in English. Quality of included studies was appraised using a modified Downs and Black tool.A total of 83 studies were included; 24 describing comparable data and 59 including a correlation analysis. The majority of correlations reported between indirect and direct measures were low-to-moderate (range: -0.56 to 0.89). Overall, 72% of the indirect measures overestimated the directly measured values. Combined gender, as well as male- and female-only data comparing indirect measures to accelerometery, heart rate monitoring or direct observation, all reported an overestimation by indirect method. A similar trend was observed in combined gender data comparing indirect measures with doubly labelled water; however, the opposite trend was observed in the male- and female-only data with a slight underestimation by indirect measure.Substantial discrepancies and moderate correlations between indirect methods and direct measures of assessing PA in pediatric populations are of concern, especially when trying to establish relationships with health outcomes.

<h3>Introduction</h3> Canadians9 red blood cell (RBC) folate has shifted towards high concentrations (&gt;1360 nmol/l based on the 97th percentile of Americans post-fortification (NHANES)). Determinants of these high concentrations are poorly understood, though an association has been posited between high intakes of folic acid and adverse health outcomes. This research investigated determinants of high folate concentrations in Canadians. <h3>Methods</h3> RBC folate concentrations from the nationally representative Canadian Health Measures Survey were examined in participants aged 6–79 years (N=5248). The population was described using frequencies and percentages. Sociodemographic, behavioural and clinical determinants of high RBC folate concentrations were examined using univariate and separate multiple logistic regression models controlling for age and household income. <h3>Results</h3> The greatest proportion of high concentrations occurred in females (42.5%), higher age groups (6–11 years (36.4%), 12–19 years (25.6%), 20–39 years (32.9%), 40–59 years (44.5%), 60–79 years (53.6%)) and higher income quartiles (33.5% (Q1), 37.6% (Q2), 41.6% (Q3), 46.6% (Q4)). Folic acid containing supplement users had a greater prevalence of high concentrations (62.8%) than non-users (37.2%). Prevalence of high concentrations climbed with increasing intake of fruit/vegetables (&gt;3 times per day (46.8%)) and grain products (&gt;3 times per day (45.5%)). Never smokers (39.5%) and former smokers (49.1%) had a greater prevalence of high concentrations than daily smokers (28.4%). Detailed regression results will be presented at the conference. <h3>Conclusion</h3> Determinants of high folate concentrations should be considered when refining folic acid supplementation and fortification policies. Future research on the relationship between high folate concentrations and health outcomes is warranted.

Objectives In light of a shift to considering the integration of movement behaviors, the purpose of this study was to examine an extended multi-component theory of planned behavior (TPB) framework to predict parent support and parent perceived behavior of the Canadian 24-h movement behaviors in children and youth including light physical activity (LPA), moderate to vigorous physical activity (MVPA), sleep, and screen-time. Design Cross-sectional survey. Method A representative sample of Canadian parents (N = 1208) with children aged 5–17 years of age, completed measures of TPB, support behaviors, and the four child health behaviors via a panel survey. Results Controlling for child age, structural equation models showed that child health behavior was predicted by parental support of that behavior (10–27% of variance explained) and intention and perceived capability to support explained support behaviors (42–53% variance explained). The TPB antecedents of intention, however, differed by each health behavior. Conclusions Parental support behaviors are related to perceived child/youth behavior. Parental support is partly dependent on intention and perceptions of parental capability but the interventions to promote the underlying social cognitions behind parental support may be different for MVPA, LPA, sleep, and screen time restriction.

Objective This study describes the distributions of body mass index (BMI) and movement behaviors among schoolchildren from 13 countries across a continuum of human development. Methods Data were from a cross‐sectional study of 9‐11‐year‐old children (n = 8055) recruited from 269 urban schools in 13 countries, and an additional 7 rural schools in one of these countries (Mozambique). BMI was derived from objectively measured heights and weights. Moderate‐ to vigorous‐intensity physical activity (MVPA), sedentary time (SED), and sleep duration were assessed by waist‐worn Actigraph GT3X+ accelerometers. Linear models were used to describe the distributions of BMI z‐scores, MVPA, SED, and sleep among sites across varying Human Development Indices (HDIs). Results Mean MVPA, SED, and sleep duration were 63.1 ± 27.3 minutes/day, 508.7 ± 72.4 minutes/day, and 8.8 ± 0.9 hours/night, respectively. Overall, 2.1% of the sample were thin, 19.5% overweight, and 11.7% were obese. Density curves (BMI z‐scores and SED) for urban children in Mozambique showed significantly higher mean values compared with rural children. Boys had significantly higher mean MVPA compared with girls. Mean BMI z‐scores were positively associated ( β = .02; P = .004) with HDI, mean daily MVPA minutes were negatively associated ( β = −.38; P = .025) with HDI, and mean SED time was positively associated with HDI ( β = 1.18; P = .049). No significant association ( β = .01; P = .29) was observed between sleep duration and HDI. Conclusion Our findings show distinct differences in BMI and movement behavior profiles between urban and rural children in Mozambique. Mean BMI z‐scores, MVPA, and SED differed by country HDI. These findings support the need to include both rural and urban participants in study samples.

Background: Previous work has shown little association between self-report and directly measured physical activity. The objective of this study was to investigate the relationships between self-reported and directly assessed measures of physical activity and sedentary time by weight status in Kenyan children.Methods: Direct assessment of body weight, physical activity and sedentary time of 563 children was collected through anthropometry and accelerometry, while self-reported assessment was achieved by administering a questionnaire.Results: Under/healthy weight children had significantly higher directly measured mean daily minutes of moderate-to-vigorous physical activity (MVPA) compared to overweight/obese children (39 vs 20 minutes); had lower mean weekend-day minutes of sedentary time (346 vs 365 minutes); had a higher proportion who met accepted physical activity guidelines (15.3% vs 2.6%); and a higher number reported using active transportation to/from school (49.2% vs 32.4%). Self-reported time spent outside before and after school and active transport to/from school were significantly associated with mean weekday minutes of MVPA (r-value range = 0.12–0.36), but only for the under/healthy weight children.Conclusions: The results of this study found a number of differences in the accumulation of MVPA and sedentary time by weight status and weak-to-moderate correlations between self-report and direct measures of weekday and weekend-day physical activity among the under/healthy weight children.

&lt;p&gt;&lt;strong&gt;Background&lt;/strong&gt;&lt;/p&gt; &lt;p&gt;Healthy childhood development is fostered through sufficient physical activity (PA; including time outdoors), limiting sedentary behaviours (SB), and adequate sleep; collectively known as movement behaviours. Though the COVID-19 virus outbreak has changed the daily lives of children and youth, it is unknown to what extent related restrictions may compromise the ability to play and meet movement behaviour recommendations. This secondary data analysis examined the immediate impacts of COVID-19 restrictions on movement and play behaviours in children and youth.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Methods&lt;/strong&gt;&lt;/p&gt; &lt;p&gt;A national sample of Canadian parents (&lt;em&gt;n&lt;/em&gt; = 1472) of children (5–11 years) or youth (12–17 years) (54% girls) completed an online survey that assessed immediate changes in child movement and play behaviours during the COVID-19 outbreak. Behaviours included PA and play, SB, and sleep. Family demographics and parental factors that may influence movement behaviours were assessed. Correlations between behaviours and demographic and parental factors were determined. For open-ended questions, word frequency distributions were reported.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Results&lt;/strong&gt;&lt;/p&gt; &lt;p&gt;Only 4.8% (2.8% girls, 6.5% boys) of children and 0.6% (0.8% girls, 0.5% boys) of youth were meeting combined movement behaviour guidelines during COVID-19 restrictions. Children and youth had lower PA levels, less outside time, higher SB (including leisure screen time), and more sleep during the outbreak. Parental encouragement and support, parental engagement in PA, and family dog ownership were positively associated with healthy movement behaviours. Although families spent less time in PA and more time in SB, several parents reported adopting new hobbies or accessing new resources.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Conclusions&lt;/strong&gt;&lt;/p&gt; &lt;p&gt;This study provides evidence of immediate collateral consequences of the COVID-19 outbreak, demonstrating an adverse impact on the movement and play behaviours of Canadian children and youth. These findings can guide efforts to preserve and promote child health during the COVID-19 outbreak and crisis recovery period, and to inform strategies to mitigate potential harm during future pandemics.&lt;/p&gt;

Objectives: This study investigated associations between weather conditions, physical activity, and sedentary time in primary school-aged children in Australia and Canada. Methods: Cross-sectional data on 9–11-year-old children from the Australian ( n = 491) and Canadian ( n = 524) sites of the International Study of Childhood Obesity, Lifestyle and the Environment were used. Minutes of daily moderate-to-vigorous-physical-activity (MVPA) and sedentary time were determined from 7-day, 24-h accelerometry (Actigraph GT3X+ triaxial accelerometer). Day-matched weather data (temperature, rainfall, snowfall, relative humidity, wind speed) were obtained from the closest weather station to participants’ schools. Covariates included parental highest education level, day type, sex, and BMI z-scores. Generalized mixed model analyses allowing for clustering of participants within schools were completed. Scatterplots with Loess curves were created for maximum temperature, MVPA, and sedentary time. Results: Daily maximum temperature was significantly associated with MVPA and sedentary time in Australia (MVPA p = .05, sedentary p = .01) and Canada ( p &lt; .001, p = .001). Rainfall was negatively associated with MVPA in Australia ( p &lt; .001) and positively associated with sedentary time in Canada ( p = .02). Conclusions: MVPA and sedentary time appear to be optimal when the maximum temperature ranges between 20°C and 25°C in both countries. The findings have implications for study design and interpretation for surveillance and intervention studies.

This study describes and compares the percentages of Canadian children and youth who adhere to different operational definitions of the moderate-to-vigorous physical activity (MVPA) recommendation of 60 minutes per day.Data for 6- to 17-year-olds (n = 5,608) were collected from 2007 through 2015 as part of the Canadian Health Measures Survey. MVPA was measured using the Actical accelerometer. The MVPA recommendation was operationalized as accumulating 60 minutes of MVPA every day, on most days, and on average.Data from the most recent cycle of the Canadian Health Measures Survey indicate that 7% of children and youth accumulated at least 60 minutes of MVPA on at least 6 out of 7 days, and 33% achieved a weekly average of at least 60 minutes per day. Boys accumulated more MVPA than did girls, and 6- to 11-year-olds accumulated more MVPA than did 12- to 17-year-olds. Regardless of how adherence to the recommendation is operationalized, MVPA levels among Canadian children and youth did not change over the 9-year period from 2007 to 2015.The majority of Canadian children do not meet the physical activity recommendation, regardless of the operational definition used. However, the discrepancies between results based on different interpretations of the 60-minutes-per-day recommendation highlight the importance of explicitly reporting how recommendations are operationalized to avoid misinterpreting trends and comparisons.

Objective The aim of this study is to examine the associations of total sedentary time and patterns of sedentary time with cardiometabolic biomarkers in a large representative sample of Canadian adults. Methods The study is based on 4935 adults aged 20–79years, from the 2007/09 and 2009/11 Canadian Health Measures Survey. Total sedentary time, patterns of sedentary time (≥20minute prolonged sedentary bouts, number of sedentary breaks), and moderate- to vigorous-intensity physical activity (MVPA) were accelerometer-derived. Waist circumference, systolic and diastolic blood pressure, high-density lipoprotein (HDL) cholesterol, and C-reactive protein were measured. Triglycerides, low-density lipoprotein (LDL) cholesterol, insulin, and glucose were also measured in a fasting sub-sample (n =2551). Results Total sedentary time and time in ≥20minute prolonged sedentary bouts were associated with higher insulin and lower diastolic blood pressure levels (P <0.05). On average, each additional 10 breaks/day was associated with 0.83 (95%CI: 1.35, 0.31) cm lower waist circumference, 0.32 (0.62, 0.02) mmHg lower systolic blood pressure, 0.01 (0.00, 0.02) mmol/l higher HDL-cholesterol, 3.72 (1.34, 6.13) % lower triglycerides, 0.57 (0.23, 0.92) % lower glucose, and 4.19 (1.80, 6.63) % lower insulin. Conclusion These findings in a large representative sample of Canadian adults indicate that breaking up sedentary time may be particularly important for cardiometabolic health.

To assess the validity of the new Actical accelerometer step count function.Actical step counts were compared according to two criterion standards. 1) Eight Acticals were assessed using a mechanical shaker table under six different testing conditions. 2) Thirty-eight volunteers (aged 9-59 yr) wore eight Acticals and eight Actigraphs during treadmill walking (50 and 83 m.min(-1)) and running (133 m.min(-1)) for 6 min at each speed. Steps were counted during the second and fourth minutes of each speed by a trained observer.The correlation between Actical step counts and the mechanical shaker step counts was excellent (r = 1.0). Compared with visually counted steps, both the Actical and Actigraph step counts were significantly different at 50 m.min(-1); however, no significant differences were evident at 83 and 133 m.min(-1). The criterion-related validity correlations (r) for the Actical and Actigraph, respectively, were 0.73 and 0.52 at the slow walk condition and 0.99 and 0.99 at the normal walk and run conditions.The new step count function of the Actical accelerometer provides valid estimates of step counts at 83 and 133 m.min(-1) on a range of healthy participants.

Background The American Academy of Pediatrics recommends developmental screening at multiple visits using both a general developmental tool and an autism spectrum disorder (ASD)-specific tool. The Canadian Paediatric Society recommends screening at a single visit at 18 months. There is no consensus on which tool is best suited for one-time screening. The Infant Toddler Checklist (ITC) identifies children who are at risk for communication impairment, may detect ASD, and may be a useful screening tool at the 18-month visit. Objectives To examine the screening test accuracy of the ITC at the 18-month visit to predict school readiness at kindergarten age. Design/Methods This prospective cohort study included children who attended primary care health supervision visits in Toronto, Canada. Parents completed the ITC at the 18-month visit and teachers completed the Early Development Instrument (EDI - a population-level measure of school readiness in kindergarten) at 4-6 years. An ITC screen is positive if there is concern for expressive speech delay (speech composite below the 10th percentile) and/or other communication delay (social composite, symbolic composite or the total score below the 10th percentile). Children were considered overall vulnerable on the EDI if at least one of five domains was below the 10th percentile of the Ontario population: language and cognitive development; physical health and well-being; social competence; emotional maturity; communication skills and general knowledge. We calculated screening test properties with 95% confidence intervals (CIs), using EDI vulnerability as the criterion measure. We used multivariable regression models to examine the association between the ITC and EDI domains. Results Of 293 children, 30 (10%) had a positive ITC. At follow-up, 54 (18%) children had a teacher-reported EDI vulnerability. The specificity (range, 87%-96%) and negative predictive value (range, 83%-95%) for the ITC were high; false positive rate was low (range, 4%-13%); sensitivity was low (range, 11%-37%). A positive ITC was associated with a lower score in EDI language and cognitive development (b= -0.62, 95% CI: -1.25, -0.18; P=0.046) and EDI communication skills and general knowledge (b= -1.08, 95% CI: -2.10, -0.17; P=0.036). We found no evidence of an association between ITC and EDI vulnerability. Conclusion The ITC at 18 months had high specificity (87%-96%) suggesting that most children with a negative ITC will demonstrate school readiness at 4-6 years. False positive rates were low, minimizing over-diagnosis. The ITC, with its focus on speech and language, communication disorders and ASD, may be a candidate for screening at the 18-month visit.

No abstract is provided for this article.