ABSTRACT
This study aims to assess the prevalence of different modes of commuting to school and work for 10-12year-olds and their parents; to assess the associations with demographic variables (country, sex, parental education and ethnicity) and with weight status in eight European countries. As part of the ENERGY project a cross-sectional survey was conducted in 2010 in which modes of commuting and socio-demographic variables for children (N=7903) and one of their parents (n=6455) were measured by questionnaires. Children's weight and height were objectively measured; parents self-reported their weight and height. Logistic multilevel regression analyses assessed the associations between mode of commuting and overweight. Differences between countries and differences in mode of commuting according to demographic variables were tested using χ2-test and Marascuilo's Post-hoc analysis. There were marked differences between countries, especially regarding cycling to school, which was common in The Netherlands and Norway and rare in Greece and Spain. Demographic variables were associated with mode of commuting in children and parents. Mode of commuting was not associated with being overweight in children, after adjustment for demographic variables. Bicycling to work, but not other modes of commuting, was significantly inversely associated with being overweight among parents (OR=0.74 (95%CI 0.57-0.97)). Interventions targeting active commuting may promote cycling, and should take into account the differences regarding demographic variables.
Subject(s)
Body Weight/physiology , Overweight/epidemiology , Schools , Transportation/statistics & numerical data , Workplace , Adolescent , Bicycling/statistics & numerical data , Child , Cross-Sectional Studies , Europe/epidemiology , Family Characteristics , Female , Humans , Male , Parents , Surveys and QuestionnairesABSTRACT
OBJECTIVE: The purpose of the present study was to investigate the associations of family sociodemographic characteristics with children's weight status and whether these potential associations are mediated by children's breakfast habits. DESIGN: A school-based survey among 10-12-year-old children was conducted in eight European countries. Children's weight and height were measured and breakfast habits and family sociodemographic characteristics were self-reported by 5444 children and their parents. International Obesity Task Force cut-off points were used to categorize children as overweight/obese or normal weight. Mediation analyses were used to test the potential mediating effect of children's breakfast consumption on the associations between family sociodemographic characteristics and children's overweight/obesity. SETTING: Schools in eight European countries participating in the ENERGY (EuropeaN Energy balance Research to prevent excessive weight Gain among Youth) project. SUBJECTS: Children aged 10-12 years and their parents (n 5444). RESULTS: Children's reported daily breakfast consumption varied from 56 % in Slovenia to 92 % in Spain on weekdays and from 79 % in Greece to 93 % in Norway on weekends. Children of native parents, with both parents employed and with at least one parent having more than 14 years of education were more likely to consume breakfast daily and less likely to be overweight/obese. Finally, mediation analyses revealed that the association of parental nationality and parental educational status with children's overweight/obesity was partially mediated by children's daily breakfast consumption. CONCLUSIONS: The study shows that the lower likelihood of being overweight/obese among 10-12-year-old children of native background and higher parental educational status was partially mediated by children's daily breakfast consumption.
Subject(s)
Breakfast , Child Nutritional Physiological Phenomena , Family , Feeding Behavior , Overweight/epidemiology , Pediatric Obesity/epidemiology , Body Mass Index , Breakfast/ethnology , Child , Child Nutritional Physiological Phenomena/ethnology , Cohort Studies , Cross-Sectional Studies , Educational Status , Emigrants and Immigrants/education , Energy Intake/ethnology , Energy Metabolism , Europe/epidemiology , Family/ethnology , Feeding Behavior/ethnology , Female , Humans , Male , Nutrition Surveys , Overweight/ethnology , Overweight/prevention & control , Parents/education , Pediatric Obesity/ethnology , Pediatric Obesity/prevention & control , Prevalence , Socioeconomic FactorsABSTRACT
OBJECTIVE: To investigate the magnitude and country-specific differences in underestimation of children's weight status by children and their parents in Europe and to further explore its associations with family characteristics and sociodemographic factors. DESIGN: Children's weight and height were objectively measured. Parental anthropometric and sociodemographic data were self-reported. Children and their parents were asked to comment on children's weight status based on five-point Likert-type scales, ranging from 'I am much too thin' to 'I am much too fat' (children) and 'My child's weight is way too little' to 'My child's weight is way too much' (parents). These data were combined with children's actual weight status, in order to assess underestimation of children's weight status by children themselves and by their parents, respectively. Chi-square tests and multilevel logistic regression analyses were conducted to examine the aims of the current study. SETTING: Eight European countries participating in the ENERGY (EuropeaN Energy balance Research to prevent excessive weight Gain among Youth) project. SUBJECTS: A school-based survey among 6113 children aged 10-12 years and their parents. RESULTS: In the total sample, 42·9 % of overweight/obese children and 27·6 % of parents of overweight/obese children underestimated their and their children's weight status, respectively. A higher likelihood for this underestimation of weight status by children and their parents was observed in Eastern and Southern compared with Central/Northern countries. Overweight or obese parents (OR=1·81; 95 % CI 1·39, 2·35 and OR=1·78, 95 % CI 1·22, 2·60), parents of boys (OR=1·32; 95 % CI 1·05, 1·67) and children from overweight/obese (OR=1·60; 95 % CI 1·29, 1·98 and OR=1·76; 95 % CI 1·29, 2·41) or unemployed parents (OR=1·53; 95 % CI 1·22, 1·92) were more likely to underestimate children's weight status. CONCLUSIONS: Children of overweight or obese parents, those from Eastern and Southern Europe, boys, younger children and children with unemployed parents were more likely to underestimate their actual weight status. Overweight or obese parents and parents of boys were more likely to underestimate the actual weight status of their children. In obesity prevention such underestimation may be a barrier for behavioural change.
Subject(s)
Energy Intake , Energy Metabolism , Obesity/epidemiology , Overweight/epidemiology , Weight Gain , Body Mass Index , Child , Cross-Sectional Studies , Europe/epidemiology , Female , Humans , Logistic Models , Male , Obesity/prevention & control , Overweight/prevention & control , Socioeconomic Factors , Surveys and QuestionnairesABSTRACT
OBJECTIVE: The main objective was to assess the relationship of breakfast skipping, television (TV) viewing at breakfast and breakfast without TV with weight status among parents of 10-12-year-olds in eight European countries. DESIGN: A cross-sectional survey assessed breakfast eating and TV viewing at breakfast by three frequency questions and parents were categorized into: (i) breakfast skippers; (ii) breakfast with TV (TV watchers at breakfast); and (iii) breakfast without TV (breakfast eaters who do not watch TV during breakfast). Self-reported weight and height were used to categorize weight status as underweight, normal weight, overweight and obese. Multinomial logistic regression analyses were conducted with weight status as the dependent variable and breakfast habits as predictors, adjusting for sex, ethnicity and level of education. SETTING: The survey was conducted in 2010 in 199 primary schools across eight European countries participating in the ENERGY (EuropeaN Energy balance Research to prevent excessive weight Gain among Youth) cross-sectional study. SUBJECTS: Parents (n 6512) of 10-12-year-olds responded to the questionnaire. RESULTS: In the total study sample, with breakfast without TV as the reference group and adjusting for sex, ethnicity and level of education, the OR of being respectively overweight or obese (compared with normal weight) was 1.2 (95% CI 1.0, 1.4) or 1.8 (95% CI 1.5, 2.3) for breakfast skippers. The OR of being respectively underweight or obese was 0.5 (95% CI 0.2, 0.9) or 1.4 (95% CI 1.1, 1.8) for breakfast with TV. CONCLUSIONS: Breakfast skippers were significantly more likely to be overweight and obese, and those eating breakfast while watching TV were significantly more likely to be obese and less likely to be underweight.
Subject(s)
Body Weight , Breakfast , Feeding Behavior , Television , Child , Cross-Sectional Studies , Energy Metabolism , Ethnicity , Europe , Female , Health Behavior , Humans , Male , Obesity/epidemiology , Obesity/prevention & control , Overweight/epidemiology , Overweight/prevention & control , Parents/education , Surveys and QuestionnairesABSTRACT
BACKGROUND: To explore differences in personal and home environmental factors that are regarded as determinants of energy balance-related behaviors (EBRBs) according to parental education and ethnic background among 10-12 year old schoolchildren across Europe. METHODS: A school-based survey among 10-12 year olds was conducted in eight countries across Europe. A range of personal and home environment variables relevant for soft drink consumption, daily breakfast, sport participation and TV time was assessed by means of child report. Personal factors included attitude, health beliefs, and preference/liking. Home environment factors included parental subjective norm, modeling, support, practices and home availability. Children were classified based on parental education (i.e., low vs. high) and ethnic background (i.e., native vs. non-native). Data from 6018 children originating from 83 schools were included in the analyses. RESULTS: Multilevel logistic regression analyses showed that the majority of the factors tested -and especially home environment variables- were more favorable among children from higher educated parents and from native ethnicity. None of the personal and home environment factors was found to be more favorable among children from lower educated parents or non-native ethnicity. CONCLUSIONS: The present study indicates that schoolchildren from lower educated and non-native parents across Europe have EBRB-related beliefs and are exposed to home environments that are less favorable for engagement in healthy EBRBs.
Subject(s)
Ethnicity/statistics & numerical data , Health Behavior , Health Knowledge, Attitudes, Practice , Obesity/prevention & control , Parents , Breakfast , Carbonated Beverages/statistics & numerical data , Child , Cross-Sectional Studies , Educational Status , Energy Intake , Europe , Exercise , Female , Humans , Male , Sports/statistics & numerical data , Television/statistics & numerical dataABSTRACT
BACKGROUND: Polymorphism rs1049434 characterizes the nonsynonymous exchange of adenosine (A) by thymidine (T) in the gene for monocarboxylate transporter 1 (MCT1). We tested whether T-allele carriers of rs1049434 demonstrate increased accumulation of markers of metabolic strain. METHODS: Physically active, healthy, young male subjects (n = 22) conducted a power-matched one-legged cycling exercise to exhaustion. Metabolic substrates in capillary blood, selected metabolic compounds, and indices for the slow oxidative phenotype of vastus lateralis muscle were quantified in samples collected before and after exercise. The genotypes of the rs1049434 polymorphism were determined with polymerase chain reactions. RESULTS: One-legged exercise affected the concentration of muscle metabolites entering the tricarboxylic acid cycle, such as acetyl-co-enzyme A (+448%) and acetyl-L-carnitine (+548%), muscle glycogen (-59%), and adenosine monophosphate (-39%), 30 min post-exercise. Exercise-related variability in the muscular concentration of glycogen, long-chain acyl co-enzyme As and a triglyceride, nicotinamide adenine dinucleotide (NADH), and adenosine monophosphate (AMP) interacted with rs1049434. T-allele carriers demonstrated a 39% lesser reduction in glycogen after exercise than non-carriers when NADH increased only in the non-carriers. Muscle lactate concentration was 150% higher, blood triacyl-glyceride concentration was 53% lower, and slow fiber percentage was 20% lower in T-allele carriers. DISCUSSION: The observations suggest a higher anaerobic glycolytic strain during exhaustive exercise and a lowered lipid handling in T-allele non-carriers.
Subject(s)
Alleles , Exercise , Monocarboxylic Acid Transporters , Polymorphism, Single Nucleotide , Symporters , Humans , Male , Monocarboxylic Acid Transporters/genetics , Monocarboxylic Acid Transporters/metabolism , Adult , Symporters/genetics , Symporters/metabolism , Young Adult , Muscle, Skeletal/metabolism , Glycogen/metabolism , GenotypeABSTRACT
Objectives: This study aims to quantify the cross-sectional and prospective associations between quality of life (QoL) and moderate-to-vigorous physical activity (MVPA). Methods: This study was based on the Swiss children's Objectively measured PHYsical Activity cohort. The primary endpoint is the overall QoL score and its six dimensions. The main predictor is the average time spent in MVPA per day. Linear mixed effects and linear regression models respectively were used to investigate the cross-sectional and prospective associations between MVPA and QoL. Results: There were 352 participants in the study with complete data from baseline (2013-2015) and follow-up (2019). MVPA was positively associated with overall QoL and physical wellbeing (p = 0.023 and 0.002 respectively). The between-subject MVPA was positively associated with the overall QoL, physical wellbeing, and social wellbeing (p = 0.030, 0.017, and 0.028 respectively). Within-subject MVPA was positively associated with physical wellbeing and functioning at school (p = 0.039 and 0.013 respectively). Baseline MVPA was not associated with QoL 5 years later. Conclusion: Future longitudinal studies should employ shorter follow-up times and repeat measurements to assess the PA and QoL association.
Subject(s)
Accelerometry , Quality of Life , Child , Humans , Adolescent , Cross-Sectional Studies , Ethnicity , ExerciseABSTRACT
BACKGROUND: To assess the association of eating meals, and never watching TV while eating meals, with weight status among children, ages 10-12 years across Europe. METHODS: 7915 children (mean age: 11.5 years) in eight European countries (Belgium, Greece, Hungary, the Netherlands, Norway, Slovenia, Spain and Switzerland) completed a questionnaire at school. Data on meals eaten the day before questionnaire administration and the frequency of eating meals while watching TV were collected. Height and weight of the children were objectively assessed. Multinomial and binary regression analyses were conducted to test associations of eating meals (adjusted for gender and ethnicity) and never watching TV while eating meals (adjusted for gender, ethnicity and total TV time) with overweight/obesity, and to test for country- and socio-demographic differences. RESULTS: The proportions of children reporting eating breakfast, lunch and dinner were 85%, 96%, and 93% respectively, and 55%, 46% and 32% reported to never watch TV at breakfast, lunch and dinner respectively. The children who ate breakfast (OR = 0.6 (95% CI 0.5-0.7)) and dinner (OR = 0.4 (95% CI 0.3-0.5)), had lower odds of being overweight compared to those who did not. The children who never watched TV at lunch (OR = 0.7 (95% CI 0.7-0.8)) and dinner (OR = 0.8 (95% CI 0.7-0.9)) had lower odds of being overweight compared to those who watched TV at the respective meals. CONCLUSIONS: The odds of being overweight was lower for children who ate breakfast and dinner compared to those who did not eat the respective meals. The odds of being overweight was lower for children who reported to never watch TV at lunch and dinner compared to those who did. A focus towards meal frequency and watching TV during meals in longitudinal and interventions studies in prevention of overweight and obesity, may contribute to a better understanding of causality.
Subject(s)
Body Weight , Feeding Behavior , Meals , Television , Body Mass Index , Child , Cross-Sectional Studies , Energy Intake , Europe , Female , Humans , Male , Overweight/epidemiology , Pediatric Obesity/epidemiology , Surveys and QuestionnairesABSTRACT
BACKGROUND: Overweight in children and adolescents have increased significantly and are a major public health problem. To allow international comparisons, Switzerland joined the European study 'ENERGY' cross sectional survey consortium that investigated the prevalence of overweight and obesity as well as selected dietary, physical and sedentary behaviors of 10-12 years old pupils across seven other countries in Europe. The aims of the present study was to compare body composition and energy-balance related behaviors of Swiss schoolchildren to those of the seven European ENERGY-countries and to analyze overweight and energy-balance related behaviors of Swiss children according to socio-demographic factors. METHODS: A school-based cross-sectional study among 10-12 year old children was conducted in Switzerland and seven other European countries using a standardized protocol. Body height, weight and waist-circumference were measured by trained research assistants. Energy-balance related behaviors -i.e. selected dietary, physical activity and screen-viewing behaviors were assessed by questionnaires. Weight status and behaviors in Switzerland were compared to the seven European ENERGY countries. Within the Swiss sample, analyses stratified by gender, parental education and ethnicity were performed. RESULTS: Data of 546 Swiss children (mean age 11.6±0.8y, 48% girls) were obtained and compared to the ENERGY- results (N=7.148; mean age 11.5±0.8y, 48% girls). In Switzerland significantly less children were overweight (13.9%) or obese (2.3%) compared to the average across the ENERGY-countries (23.7% and 4.7%, respectively), and were even somewhat lower than the ENERGY countries with the lowest prevalence. Sugar sweetened beverage intakes and breakfast habits of Swiss children did not differ significantly from those of ENERGY. However, the mean time devoted by Swiss children to walking or cycling to school and attending sports activities was significantly higher and screen time significantly lower compared to the other ENERGY-countries. Within the Swiss, sample relatively large and consistent differences were observed between children from native and non-native ethnicity. CONCLUSIONS: The prevalence of overweight and obesity among Swiss children are substantial but significantly lower compared to all other European ENERGY-Partners, probably due to the fact that Swiss children were found to be more active and less sedentary comparing to the rest of the European sample.
Subject(s)
Body Composition , Health Behavior , Obesity/epidemiology , Overweight/epidemiology , Body Mass Index , Breakfast , Child , Cross-Sectional Studies , Energy Metabolism , Europe/epidemiology , Feeding Behavior , Female , Humans , Male , Parents/education , Prevalence , Reproducibility of Results , Sedentary Behavior , Socioeconomic Factors , Surveys and Questionnaires , Switzerland/epidemiology , Waist CircumferenceABSTRACT
COVID-19 restrictions and the instructions to stay at home (SaH) may have had an impact on child behavior including physical activity (PA) and health-related quality of life (HRQoL) in Switzerland. Therefore, we investigated PA and HRQoL during and after the SaH in 57 Swiss school children aged 7 to 12 years (M = 10.44; SD = 1.34). PA was measured using accelerometry (Actigraph GT3X) and HRQoL using the Kid-KINDLR questionnaire. During and post data was compared using paired sample t-tests. Independent t-tests were used to compare the HRQoL of physically active children with non-physically active children. PA in light (d = -0.56), moderate (d = -0.44), moderate-to-vigorous (d = -0.28) as well as overall HRQoL (d = -0.66), psychological well-being (d = -0.48), self-esteem (d = -0.39), friends (d = -0.70) and everyday functioning (d = -0.44), were significantly lower during SaH than afterwards. Children who adhered to PA recommendations (+60 min of moderate-to-vigorous PA) during SaH had a better overall HRQoL (d = 0.61) and psychological well-being (d = 0.56) than those who did not. Since PA levels and HRQoL were lower during SaH compared to afterwards, it seems that the restrictions negatively impacted children's PA and HRQoL. During future SaHs, promoting children's PA and HRQoL seems important.
Subject(s)
COVID-19 , Quality of Life , Accelerometry , COVID-19/epidemiology , Child , Exercise/psychology , Humans , SARS-CoV-2 , Switzerland/epidemiologyABSTRACT
BACKGROUND: The COVID-19 pandemic and the resulting containment measures had and still have a profound impact on everyday life. Both the fear of infection and the imposed restrictions can have biopsychosocial consequences. The aim of the present study was to analyze whether there is a difference in the health-related quality of life (HRQoL) of primary school children in 2014/15 compared to in 2020, the first year of the COVID-19 pandemic. METHODS: The present study included 1,712 children aged 5 to 11 years who either participated in the baseline assessment of the SOPHYA cohort study in 2014/15 or were newly recruited during follow-up of the cohort in 2020. In both surveys, the children invited for participation were identified based on registry data. HRQoL was assessed with the validated KINDL-R questionnaire, which scores HRQoL along six different dimensions. RESULTS: The overall scores (82.4 [81.8; 83.0] vs. 79.6 [79,1; 80.2]), and in particular the emotional well-being scores (85.6 [84.6; 86.6] vs. 83.3 [82.4; 84.2]), were lower during the year of the pandemic (2020) compared to the survey year 2014/15. The highest decrease between 2014/15 and 2020 in the adjusted models was seen for the youngest age group (-3.9 points), followed by children from families with a high income (-3.2 points), girls (-3.1 points), Swiss citizens (-3.1 points) and children from the German-speaking part of Switzerland (-3.1 points). HRQoL was particularly low during periods with restrictions and at the height of the COVID-19 waves in 2020. CONCLUSION: The SOPHYA-study showed that HRQoL, and especially emotional well-being, was lower in 5 to 11-year-old children in Switzerland during the first year of the pandemic compared to the results from the survey conducted in 2014/15. In the year of the pandemic, the scores were lowest at the height of the COVID-19 waves and their associated restrictions. As it cannot be distinguished whether fear of the disease itself or the restrictions caused this decrease in HRQoL, containment policies should keep COVID-19 infections as low as possible, but still enable children to profit from protective factors such as leisure activities, physical activity and social contact.
Subject(s)
COVID-19 , Quality of Life , Child , Child, Preschool , Cohort Studies , Cross-Sectional Studies , Female , Humans , Pandemics , SARS-CoV-2 , Schools , Surveys and Questionnaires , Switzerland/epidemiologyABSTRACT
OBJECTIVES: We tested whether objectively assessed neighbourhood characteristics are associated with moderate-to vigorous physical activity (MVPA) and cycling in Swiss children and adolescents and assessed the mediating role of the perception of the environment. METHODS: The cross-sectional analyses were based on data of 1306 participants aged 6-16 years of the population-based SOPHYA study. MVPA was measured by accelerometry, time spent cycling and the perceived environment by questionnaire. Objective environmental parameters at the residential address were GIS derived. In all analyses, personal, social and environmental factors were considered. RESULTS: MVPA showed significant positive associations with perceived personal safety and perceived access to green spaces but not with respective objective parameters. Objectively assessed main street density and shorter distance to the next public transport were associated with less cycling in adolescents. Parents' perceptions did not mediate the observed associations of the objectively assessed environment with MVPA and cycling. CONCLUSIONS: Associations between the environment and physical activity differ by domain. In spatial planning efforts to improve objective environments should be complemented with efforts to increase parental sense of security.
Subject(s)
Environment Design/statistics & numerical data , Exercise/psychology , Residence Characteristics/statistics & numerical data , Accelerometry , Adolescent , Child , Cross-Sectional Studies , Female , Humans , Male , Surveys and Questionnaires , SwitzerlandABSTRACT
Identifying correlates of sedentary behaviour across all levels of the ecological model and understanding their interrelations is a promising method to plan effective interventions. The present study examined whether the objectively assessed and the perceived neighbourhood are associated with children’s sedentary behaviour time (SBT). A comprehensive set of factors at different levels of influence across the ecological model were taken into account and analysed for mediating and modifying effects. Analyses were based on 1306 children and adolescents (6â»16 years) participating in the population-based SOPHYA-study. Accelerometers were used to assess SBT, the perceived environment was examined by a validated parental questionnaire, and objective environmental data were allocated using GIS (ArcMap 10.2, Esri, Redlands, CA, USA) for each family’s residential address. A high perceived safety was associated with less SBT. Boys, those whose residential neighbourhood was characterized by dead ends in urban areas, a low main street density in the neighbourhood of children and greenness were less likely to exhibit SBT. The association of the objective environment with the respective parental perceptions was low and no significant mediating effect was found for the perceived environment. We conclude for land-use planning to reduce sedentary behaviour objective environments should be complemented with efforts to increase parental sense of security.
Subject(s)
Child Behavior/psychology , Environment Design/statistics & numerical data , Exercise , Health Behavior/physiology , Residence Characteristics/statistics & numerical data , Sedentary Behavior , Adolescent , Child , Cross-Sectional Studies , Female , Health Surveys , Humans , Male , Recreation , Surveys and Questionnaires , Switzerland/epidemiologyABSTRACT
OBJECTIVE: We evaluated whether regional differences in physical activity (PA) and sedentary behaviour (SB) existed along language boundaries within Switzerland and whether potential differences would be explained by socio-demographics or environmental characteristics. METHODS: We combined data of 611 children aged 4 to 7 years from four regional studies. PA and SB were assessed by accelerometers. Information about the socio-demographic background was obtained by questionnaires. Objective neighbourhood attributes could be linked to home addresses. Multivariate regression models were used to test associations between PA and SB and socio-demographic characteristics and neighbourhood attributes. RESULTS: Children from the German compared to the French-speaking region were more physically active and less sedentary (by 10-15 %, p < 0.01). Although German-speaking children lived in a more favourable environment and a higher socioeconomic neighbourhood (differences p < 0.001), these characteristics did not explain the differences in PA behaviour between French and German speaking. CONCLUSIONS: Factors related to the language region, which might be culturally rooted were among the strongest correlates of PA and SB among Swiss children, independent of individual, social and environmental factors.
Subject(s)
Culture , Environment , Exercise , Residence Characteristics/statistics & numerical data , Sedentary Behavior/ethnology , Accelerometry , Child , Child, Preschool , Female , Humans , Male , Socioeconomic Factors , Switzerland/epidemiologyABSTRACT
BACKGROUND: Neighborhood attributes are modifiable determinants of physical activity (PA) and sedentary behavior (SB). We tested whether the objectively-assessed built and social environment was associated with PA and SB in Swiss youth and whether sex, age and the socioeconomic position (Swiss-SEP) modified such associations. METHODS: We combined data of 1742 youth (ages 4 to 17) from seven studies conducted within Switzerland between 2005-2010. All youth provided accelerometer data and a home address, which was linked to objective environmental data and the Swiss-SEP-index. Associations between neighborhood attributes and PA were analyzed by multivariable multilevel regression analyses. RESULTS: The extent of green areas and building density was positively associated with PA in the total sample (p < 0.05). Factors representing centrally located areas, and more schoolchildren living nearby tended to increase PA in secondary schoolchildren, boys and those from lower-ranked socioeconomic areas. In primary schoolchildren, the extent of green areas was positively associated with PA (p = 0.05). Associations between neighborhood attributes and PA were more pronounced in youth from low socioeconomic areas. CONCLUSIONS: The results indicate that some associations between neighborhood attributes and PA differ by age, sex and socioeconomic area. This should be taken into account when planning interventions to increase childhood PA.
ABSTRACT
PURPOSE: Awareness of being monitored can influence participants' habitual physical activity (PA) behavior. This reactivity effect may threaten the validity of PA assessment. Reports on reactivity when measuring the PA of children and adolescents have been inconsistent. The aim of this study was to investigate whether PA outcomes measured by accelerometer devices differ from measurement day to measurement day and whether the day of the week and the day on which measurement started influence these differences. METHODS: Accelerometer data (counts per minute [cpm]) of children and adolescents (n = 2081) pooled from eight studies in Switzerland with at least 10 h of daily valid recording were investigated for effects of measurement day, day of the week, and start day using mixed linear regression. RESULTS: The first measurement day was the most active day. Counts per minute were significantly higher than on the second to the sixth day, but not on the seventh day. Differences in the age-adjusted means between the first and consecutive days ranged from 23 to 45 cpm (3.6%-7.1%). In preschoolchildren, the differences almost reached 10%. The start day significantly influenced PA outcome measures. CONCLUSIONS: Reactivity to accelerometer measurement of PA is likely to be present to an extent of approximately 5% on the first day and may introduce a relevant bias to accelerometer-based studies. In preschoolchildren, the effects are larger than those in elementary and secondary schoolchildren. As the day of the week and the start day significantly influence PA estimates, researchers should plan for at least one familiarization day in school-age children and randomly assign start days.