Petra Jurić

Objective: The aim of this study was to examine the effectiveness of a real‐world, population‐scaled, school‐based physical activity (PA) intervention that provided two to three additional physical education lessons per week to children aged 6 to 14 years in Slovenia.Methods: More than 34,000 participants from over 200 schools were compared with a similar number of nonparticipants from the same schools. Generalized estimating equations were used to estimate the effects of differing levels of exposure to the intervention (i.e., from 1–5 years) on BMI in children with normal weight, overweight, or obesity at baseline.Results: BMI was lower in the intervention group, irrespective of participation duration or baseline weight status. The difference in BMI increased with the program duration, with maximal effects being seen after 3 to 4 years of participation, and was consistently larger for children with obesity (peaking at 1.4 kg/m² [95% CI: 1.0–1.9] for girls with obesity and peaking at 0.9 kg/m² [95% CI: 0.6–1.3] for boys with obesity). The program started to become effective at reversing obesity after 3 years, whereas the lowest numbers needed to treat (NNTs) were observed after 5 years (NNTs = 17 for girls and 12 for boys).Conclusions: The population‐scaled, school‐based PA intervention was effective in preventing and treating obesity. The effects were the greatest in children initially presenting with obesity, such that the program was able to benefit children needing support the most.

Background: A large number of wearable activity monitor models are released and used each year by consumers and researchers. As more studies are being carried out on children and adolescents in terms of sedentary behavior (SB) assessment, knowledge about accurate and precise monitoring devices becomes increasingly important. Objective: The main aim of this systematic review was to investigate and communicate findings on the accuracy and precision of consumer-grade physical activity monitors in assessing the time spent in SB in children and adolescents. Methods: Searches of PubMed (MEDLINE), Scopus, SPORTDiscus (full text), ProQuest, Open Access Theses and Dissertations, DART Europe E-theses Portal, and Networked Digital Library of Theses and Dissertations electronic databases were performed. All relevant studies that compared different types of consumer-grade monitors using a comparison method in the assessment of SB, published in European languages from 2015 onward were considered for inclusion. The risk of bias was estimated using Consensus-Based Standards for the Selection of Health Status Measurement Instruments. For enabling comparisons of accuracy measures within the studied outcome domain, measurement accuracy interpretation was based on group mean or percentage error values and 90% CI. Acceptable limits were predefined as –10% to +10% error in controlled and free-living settings. For determining the number of studies with group error percentages that fall within or outside one of the sides from previously defined acceptable limits, two 1-sided tests of equivalence were carried out, and the direction of measurement error was examined. Results: A total of 8 studies complied with the predefined inclusion criteria, and 3 studies provided acceptable data for quantitative analyses. In terms of the presented accuracy comparisons, 14 were subsequently identified, with 6 of these comparisons being acceptable in terms of quantitative analysis. The results of the Cochran Q test indicated that the included studies did not share a common effect size (Q5=82.86; P<.001). I2, which represents the percentage of total variation across studies due to heterogeneity, amounted to 94%. The summary effect size based on the random effects model was not statistically significant (effect size=14.36, SE 12.04, 90% CI −5.45 to 34.17; P=.23). According to the equivalence test results, consumer-grade physical activity monitors did not generate equivalent estimates of SB in relation to the comparison methods. Majority of the studies (3/7, 43%) that reported the mean absolute percentage errors have reported values of <30%. Conclusions: This is the first study that has attempted to synthesize available evidence on the accuracy and precision of consumer-grade physical activity monitors in measuring SB in children and adolescents. We found very few studies on the accuracy and almost no evidence on the precision of wearable activity monitors. The presented results highlight the large heterogeneity in this area of research. Trial Registration: PROSPERO CRD42021251922; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=251922

BACKGROUND Vast numbers of physical activity monitor models are being released each year and are being used by everyday consumers and researchers as well. As more studies are carried out on children and adolescents in terms of sedentary behaviour (SB) assessment, knowledge improvement about valid monitoring methods is important. OBJECTIVE Main aim of the systematic review was to investigate and communicate the findings on the accuracy of consumer-grade physical activity monitors in terms of assessing SB in children and adolescents. METHODS Searches of PubMed (MEDLINE), Scopus, SPORTDiscus (with Full Text), ProQuest, Open Access Theses and Dissertations, DART (Europe E-theses Portal), and Networked Digital Library of Theses and Dissertations electronic databases were performed. All relevant studies that compared different types of consumer-grade monitors against a comparison method in the assessment of SB, published in European languages from 2015 onwards were considered for inclusion. Risk of bias was estimated by Consensus-Based Standards for the Selection of Health Status Measurement Instruments. To enable comparisons of accuracy measures within the studied outcome domain measurement accuracy interpretation was based on group mean or percentage error values as well as 90% confidence intervals (CI). Acceptable limits were predefined as ±10% percentage error in controlled and free-living settings. To determine the number of studies with group error percentages that fall within or outside one of the sides from previously defined acceptable limits, two one-sided tests (TOST) of equivalence were carried out with the direction of measurement error also examined. RESULTS A total number of 8 studies complied with the predefined inclusion criteria, and 3 studies provided acceptable data for quantitative analyses. In terms of presented accuracy comparisons, 14 were subsequently identified with 6 of those comparisons being acceptable in terms of quantitative analysis. Results of the Cochran Q test indicated that the included studies do not share a common effect size [Q (df = 5) = 82.86; p < 0.0001]. I2 as it represents the percentage of total variation across studies that is due to heterogeneity amounted to 94%. Summary effect size based on the random effects model was not statistically significant (ES = 14.36; SE = 12.04; 90%CI = -5.45, 34.17; p = 0.23). According to equivalence tests results, consumer-grade physical activity monitors did not generate equivalent estimates of SB in relation to comparison methods. Majority of the studies that reported MAPEs have reported values less than 30%. CONCLUSIONS This is one of the only studies that focused solely on the accuracy of consumer-grade physical activity monitors when measuring SB in children and adolescents, representing a need for more research in the future. The presented results highlight heterogeneity in this area of research, of which utilized devices and cut-off points defining SB are emphasized. This study should inform the researchers, consumers, and clinicians on the measurement accuracy of widely attainable physical activity monitors when measuring SB in children and adolescents.