Study protocol for the Screen-Free Time with Friends Feasibility Trial.

BACKGROUND: Children are spending less leisure time with their friends in person and an increasing amount of time with digital screens. These changes may negatively affect children's physical and mental health. The Screen-Free Time with Friends Feasibility Trial will test the feasibility, including acceptability and compliance, of an intervention designed to reduce screen media usage and encourage physical interaction with friends during leisure time in 9-11-year-old children. METHODS: A non-randomized single-group feasibility trial will be conducted from March to October 2023 including approximately 75 children (aged 9-11 years) and 75 parents (at least 1 per child) from 3 different schools recruited from 3 different municipalities in Denmark. The Screen-Free Time with Friends intervention is a multicomponent intervention targeting families, afterschool clubs, and local communities. It has been developed using a systematic process guided by the Medical Research Council UK's framework for developing and evaluating complex interventions. With a systems perspective in mind, the intervention and implementation approach has been designed to facilitate adaptation to the specific needs of diverse local communities while maintaining the core components of the intervention. Feasibility and acceptability of the intervention will be assessed during the intervention using process evaluation inspired by the RE-AIM framework including questionnaires and interviews with the municipality project managers, research team members, local ambassadors and stakeholders, parents and school, and afterschool club personnel. In addition, participation, recruitment, retention rate, and compliance to the outcome measurements will be investigated and presented. DISCUSSION: The trial will investigate the feasibility and acceptability of the Screen-Free Time with Friends intervention, the recruitment strategy, and the planned outcome measurements. This feasibility study will investigate necessary refinements before the implementation of the intervention program in a larger cluster randomized controlled trial to evaluate its impact. CLINICALTRIALS: gov, ID: NCT05480085. Registered 29 July 2022. https://clinicaltrials.gov/ct2/show/NCT05480085?cond=Screen+free+time+with+friends&draw=2&rank=1.

The role of playgrounds in the development of children's fundamental movement skills: A scoping review.

Fundamental movement skills (FMS) are the basic skills children should develop but are low in children from high-income countries. Literature indicates that playgrounds can play an important role challenging children's balance, agility, and coordination. However, knowledge on the influence of playgrounds on children's FMS development is fragmented. The aim of the present scoping review was to create an overview of all research that is relevant when studying the influence of unstructured playground play on children's FMS. Four electronic databases (Scopus, Web of Science, SportDiscus, and PsycInfo) were searched systematically in May 2022 and October 2023 following the PRISMA guidelines, leading to a final set of 14 publications meeting the inclusion criteria. The results of these publications indicate that it is important to design playgrounds with various features targeting balance, climbing, throwing, and catching to provide opportunities for children to enhance each FMS (i.e., stability, locomotor skills, and object control skills). Also, spreading features over a large area of the playground seems to ensure ample space per child, stimulate children to use locomotor skills by moving to and from features, and to play active games without equipment. Possibly, also natural play settings develop children's FMS. These findings, however, should be read with caution. More experimental studies using objective and standardized FMS tests are needed in this research field for a more robust conclusion.

Heart rate responses, agreement and accuracy among persons with severe disabilities participating in the indirect movement program: Team Twin-an observational study.

Introduction: Heart rate (HR) monitors are rarely used by people living with disabilities (PLWD), and their accuracy is undocumented. Thus, this study aims to describe the HR response during the Team Twin co-running program and, secondly, to assess the agreement and accuracy of using HR monitors among PLWD. Methods: This 16-week single-arm observational study included 18 people with various disabilities. During the study, the subjects wore a Garmin Vivosmart 4 watch (wrist). To evaluate the agreement and accuracy we applied Garmin's HRM-DUAL™ chest-worn HR monitors for comparison with the Vivosmart 4. The HR response analysis was performed descriptively and with a mixed regression model. The HR agreement and accuracy procedure was conducted on a subsample of five subjects and analyzed using Lin's concordance analysis, Bland and Altman's limits of agreement, and Cohen's kappa analysis of intensity zone agreement. This study was prospectively registered at Clinical Trials.gov (NCT04536779). Results: The subjects had a mean age of 35 (±12.6), 61% were male, 72% had cerebral palsy were 85% had GMFCS V-IV. HR was monitored for 202:10:33 (HH:MM:SS), with a mean HR of 90 ± 17 bpm during training and race. A total of 19% of the time was spent in intensity zones between light and moderate (30%-59% HR reserve) and 1% in vigorous (60%-84% HR reserve). The remaining 80% were in the very light intensity zone (<29% HR reserve). HR was highest at the start of race and training and steadily decreased. Inter-rater agreement was high (k = 0.75), limits of agreement were between -16 and 13 bpm, and accuracy was acceptable (Rc = 0.86). Conclusion: Disability type, individual, and contextual factors will likely affect HR responses and the agreement and accuracy for PLWD. The Vivosmart 4, while overall accurate, had low precision due to high variability in the estimation. These findings implicate the methodical and practical difficulties of utilizing HR monitors to measure HR and thus physical activity in adapted sports activities for severely disabled individuals.

Device-based physical activity measures for population surveillance-issues of selection bias and reactivity.

Background: Device-based measurement in physical activity surveillance is increasing, but research design choices could increase the risk of self-selection bias and reactive behaviour. The aim of this study is to compare the self-reported physical activity profiles of four different samples: participants in a large national survey, participants in a telephone-based survey of non-responders, participants in the large national survey who accepted the invitation to device-based measuring, and the same sample during the week of monitoring. Methods: In October 2020, 163,133 Danish adults participated in a national survey and of those 39,480 signed up for device-based measurements. A balanced random sample (n = 3,750) was invited to wear an accelerometer of whom 1,525 accepted the invitation. Additionally, a short telephone-based survey on 829 non-responders to the national survey was conducted. Sociodemographic characteristics and self-reported weekly frequencies of physical activity across four domains are compared. Results: The participants in the national survey were older, more often female, and more often not working. Participants in the telephone-based survey were younger, more often doing unskilled work, and were more often active at home and at work. The participants in the device-based sample were more often active during transport and leisure in the national survey, and participants categorized in the most active category increased during the week of monitoring from 29.0% to 60.7% and from 58.5% to 81.7% for active transport and leisure activities, respectively. Conclusion: Recruiting a population representative sample for device-based measurement of physical activity is challenging, and there is a substantial risk of sample selection bias and measurement reactivity. Further research in this area is needed if device-based measures should be considered for population physical activity surveillance.

Preventing Stress among High School Students in Denmark through the Multicomponent Healthy High School Intervention-The Effectiveness at First Follow-Up.

Stress is a widespread phenomenon and young people especially are experiencing high levels of stress. School-related factors are the most frequently self-reported stressors among adolescents, but few interventions have targeted the school environment. This study evaluated the effectiveness of the Healthy High School (HHS) intervention on stress at a 9-month follow-up. The study included 5201 first-year high school students (~16 years) in Denmark. Participating schools were randomized into the HHS intervention (N = 15) or control group (N = 15). Baseline measurements were conducted in August 2016 and the follow-up was conducted in May 2017. The intervention was designed to promote well-being (primary outcome) by focusing on physical activity, meals, sleep, sense of security, and stress (secondary outcomes). The intervention comprised: structural initiatives at the school level; a teaching material; peer-led innovation workshops; and a smartphone app. The 10-item Perceived Stress Scale was used to measure stress. Intervention effects on perceived stress were estimated using an intention-to-treat approach with multiple imputations of missing data and multilevel general linear regression modelling. A total of 4577 students answered the baseline questionnaire. No statistically significant difference was found in stress between students at intervention and control schools at the follow-up (mean score: 16.7 versus 16.7, adjusted b = 0.42, 95% CI: -0.16;1.00). The HHS Study is one of the first large randomized controlled trials targeting school environmental stressors. Potential implementation failures and the failures of the program theory are discussed.

Effect of the multicomponent healthy high school intervention on meal frequency and eating habits among high school students in Denmark: a cluster randomized controlled trial.

BACKGROUND: Previous studies have shown that multicomponent interventions may improve meal frequency and eating habits in children, but evidence among young people is limited. This study evaluated the effect of the Healthy High School (HHS) intervention on daily intake of breakfast, lunch, water, fruit, and vegetables at 9-month follow-up. METHODS: The study included first-year students (≈16 years) attending high school in Denmark. Participating schools were randomized into the HHS intervention (N = 15) or control group (operating as usual) (N = 15). The intervention was designed to promote well-being (primary outcome) by focusing on healthy habits including meals, stress prevention, and strong peer relations. It included a curriculum, structural and organisational initiatives, a workshop, and a smartphone application. Students completed self-administered online questionnaires at the beginning of the school year and nine months later. To account for clustering of data, we used multilevel logistic regression analyses to estimate odds ratios (OR). We applied an intention-to-treat approach with multiple imputations of missing data. RESULTS: At baseline 4577 of 5201 students answered the questionnaire and 4512 at follow-up. In both groups the proportion of students eating breakfast decreased from approximately 50% to 40% from baseline to follow-up, and lunch frequency decreased from approximately 50% to 47%. Daily water intake, intake of fresh fruit and intake of vegetables remained unchanged from baseline to follow-up. There were no significant between group differences on any of the outcomes at first follow-up: breakfast: OR = 0.85 (95% CI: 0.65;1.10), lunch: OR = 0.96 (95% CI: 0.75;1.22), water intake: OR = 1.14 (95% CI: 0.92;1.40), intake of fresh fruit: (OR = 1.07, 95% CI: 0.84;1.37), vegetables: (OR = 1.01, 95% CI: 0.77;1.33). CONCLUSION: No evidence of an effect of the HHS intervention was found for any of the outcomes. Future studies are warranted to explore how health promoting interventions can be integrated in further education to support educational goals. Moreover, how to fit interventions to the lives and wishes of young people, by also including systems outside of the school setting. TRIAL REGISTRATION: ISRCTN, ISRCTN43284296 . Registered 28 April 2017 - retrospectively registered.

Chronic backpain among adolescents in Denmark: trends 1991-2018 and association with socioeconomic status.

Chronic backpain among adolescents is important because the prevalence is high, above 10%, and more than 10% of all adolescents experience impacts on important day-to-day activities. Chronic backpain tracks into adulthood and is associated with several health problems. The objective was to study trends in the prevalence of chronic backpain among adolescents 1991-2018, to examine the association with socioeconomic status (SES), and whether this association changed over time. The study used data from eight comparable cross-sectional school surveys of nationally representative samples of 11-15-year-olds in 1991, 1994, 1998, 2002, 2006, 2010, 2014, and 2018, which constitute the Danish arm of the international Health Behaviour in School-aged Children (HBSC) study. The participation rate was 74.6% of the eligible study population, n = 29,952. Chronic backpain was defined as self-reported backpain daily or several days a week during the last 6 months. The prevalence of chronic backpain was 11.1%, significantly increasing from 8.9% in 1991 to 11.7% in 2018. The OR for chronic backpain was 1.20 (95% CI: 1.10-1.31) in middle, and 1.56 (95% CI: 1.41-1.73) in low compared to high SES. Sensitivity analyses with two other cut-points for backpain frequency showed similar associations.Conclusion: Chronic backpain is common among adolescents and the prevalence increased from 1991 to 2018. The prevalence was highest in lower SES families. We recommend increased efforts to prevent chronic backpain. What is Known: • Chronic backpain among adolescents is common, has a high burden of disability, is associated with several health problems, and tracks into adulthood. What is New: • The prevalence of chronic backpain among adolescents in Denmark increased from 8.9% in 1991 to 11.7% in 2018. • The prevalence was highest among adolescents from lower SES families.

When Movement Moves: Study Protocol for a Multi-Method Pre/Post Evaluation Study of Two Programmes; the Danish Team Twin and Cycling Without Age.

Physical activity (PA) can improve physical, mental, and social health, leading to quality of life (QoL). However, some are unable to participate independently due to age-related impairments or disabilities. This study protocol presents the design, methods, outcomes, strengths and limitations of the study "When Movement Moves" (WMM). WMM investigates whether indirect PA in a social context, where persons are unable to participate independently, can result in outcomes similar to those of independent PA, by evaluating the effects of disabled's, elderly, volunteers', relatives' and nursing staff's participation in either the running programme (Team Twin) or cycling programme (Cycling Without Age). Both programmes seek to enhance QoL through indirect PA in a social context, making PA possible for elderly and disabled persons through PA conducted by abled-bodied volunteers. WMM is a multi-method 12-16-week pre/post evaluation with quality of life, physical, mental and social health as main outcomes. Pre/post measurements consist of questionnaires, clinical examinations, and physical and cognitive appraisal. Throughout, interviews and participant observations will be conducted. Combined results will provide essential knowledge on the effects and experiences of indirect PA. Explorative data will pave the way for further research. Findings may inform policies, guidelines and health promotion among the elderly and disabled.

What characterizes schools and students participating in health promoting school-based intervention studies? Findings from the healthy high school study.

The Healthy High School (HHS) intervention was developed to promote well-being among first-year high school students (~16 years of age) in Denmark by targeting stress, physical activity, meal habits, sleep, and sense of community. Thirty-one schools were randomly allocated to intervention (16 schools) or control (15 schools) groups in a cluster-randomized controlled trial. The purpose of this short communication was to compare characteristics of students and schools between 1) schools accepting to participate in the HHS study and non-participating schools using national survey data and 2) intervention and control schools using HHS baseline data. We included cross-sectional data from the Danish National Youth Study 2014 on 119 schools and 22,935 first-year students to characterize participating schools and students. At baseline (August 2016), students (n = 4577; 88.0%) and principals (n = 29; 96.7%) completed online questionnaires. Compared to non-participating schools, fewer HHS schools perceived their school as being popular and offered weekly sport activities outside school hours. More HHS schools had teachers engaged in health promotion activities and focused on stress prevention. The characteristics of HHS students did not differ markedly from non-participating high school students. There were no socio-demographic, outcome or contextual differences between the study arms. To ensure successful recruitment of schools it is important that the intervention meets the need of the schools and that the advantages of participation are explicit. This underlines the need for a thorough needs assessment prior to intervention development, co-creation of intervention activities with school staff, and a well-planned recruitment strategy.

School-based interventions modestly increase physical activity and cardiorespiratory fitness but are least effective for youth who need them most: an individual participant pooled analysis of 20 controlled trials.

OBJECTIVES: To determine if subpopulations of students benefit equally from school-based physical activity interventions in terms of cardiorespiratory fitness and physical activity. To examine if physical activity intensity mediates improvements in cardiorespiratory fitness. DESIGN: Pooled analysis of individual participant data from controlled trials that assessed the impact of school-based physical activity interventions on cardiorespiratory fitness and device-measured physical activity. PARTICIPANTS: Data for 6621 children and adolescents aged 4-18 years from 20 trials were included. MAIN OUTCOME MEASURES: Peak oxygen consumption (VO2Peak mL/kg/min) and minutes of moderate and vigorous physical activity. RESULTS: Interventions modestly improved students' cardiorespiratory fitness by 0.47 mL/kg/min (95% CI 0.33 to 0.61), but the effects were not distributed equally across subpopulations. Girls and older students benefited less than boys and younger students, respectively. Students with lower levels of initial fitness, and those with higher levels of baseline physical activity benefitted more than those who were initially fitter and less active, respectively. Interventions had a modest positive effect on physical activity with approximately one additional minute per day of both moderate and vigorous physical activity. Changes in vigorous, but not moderate intensity, physical activity explained a small amount (~5%) of the intervention effect on cardiorespiratory fitness. CONCLUSIONS: Future interventions should include targeted strategies to address the needs of girls and older students. Interventions may also be improved by promoting more vigorous intensity physical activity. Interventions could mitigate declining youth cardiorespiratory fitness, increase physical activity and promote cardiovascular health if they can be delivered equitably and their effects sustained at the population level.

Implementation of initiatives to prevent student stress: process evaluation findings from the Healthy High School study.

Process evaluation of public health interventions is important for understanding intervention results and can help explain why interventions succeed or fail. This study evaluated implementation of a school-based intervention combining educational and environmental strategies to prevent stress among Danish high school students. We investigated dose delivered, dose received, fidelity, appreciation, barriers and facilitators at the 15 intervention schools using mixed methods and multiple data sources: questionnaires among students, teachers and school coordinators; semi-structured interviews with school coordinators; telephone interviews with student counsellors; and focus group interviews with students and teachers. Implementation varied by schools and classes. Half of the intervention schools delivered the environmental strategies. For the educational strategies, dose delivered differed according to intervention provider. Students reported a lower dose received compared with dose delivered reported by school staff. Overall, student counsellors, school coordinators and students-especially those with low perceived stress-were satisfied with the stress preventive initiatives while teacher satisfaction varied. Five main barriers and three facilitators for implementation were identified. The use of multiple data sources and data methods created new knowledge of the implementation process which is important for the interpretation of effect evaluation and development of future interventions.

Trends in social inequality in overweight and obesity among adolescents in Denmark 1998-2018.

OBJECTIVES: The aim was to analyze trends in overweight and obesity in relation to socioeconomic position among Danish adolescents in the 20-year period 1998-2018. METHODS: The study used data on self-reported height and weight and parents' occupational social class (OSC) from 11-, 13- and 15-year-old schoolchildren in 1998, 2002, 2006, 2010, 2014 and 2018, n = 22,177. The analyses included absolute social inequality in overweight/obesity (prevalence difference between low and high OSC) and relative social inequality (OR for overweight/obesity). RESULTS: In the total sample, the prevalence of overweight and obesity was 9.7% and 1.4%, respectively, with significantly higher prevalence in low than high OSC. There were significantly increasing trends in both overweight and obesity 1998-2018 in low OSC and no significant increase in high OSC. The OR for overweight was 1.59 (1.42-1.74) in middle and 2.16 (1.89-2.46) in low OSC, OR for obesity 1.74 (1.29-2.34) in middle and 2.97 (2.15-4.11) in low OSC. Associations were not modified by survey year. CONCLUSIONS: There was a persistent absolute and relative social inequality in overweight and obesity 1998-2018 among Danish adolescents.

Study protocol of the Healthy High School study: a school-based intervention to improve well-being among high school students in Denmark.

BACKGROUND: The prevalence of low well-being, perceived stress and unhealthy behaviours is high among high school students, but few interventions have addressed these problems. The aim of this paper is to present a study protocol of a cluster randomised controlled trial evaluating the Healthy High School (HHS) intervention programme. The intervention programme is designed to improve well-being (primary outcome) by preventing 1) stress and promoting 2) sleep, 3) sense of community, 4) physical activity (PA) and 5) regular and healthy meals among high school students in Denmark. METHODS: The development of the HHS study was guided by the Intervention Mapping protocol. The intervention comprises four components: 1) a teaching material, 2) a smartphone app, 3) a catalogue focusing on environmental changes, and 4) a peer-led innovation workshop aiming at inspiring students to initiate and participate in various movement activities. The HHS study employs a cluster-randomised controlled trial design. Thirty-one high schools across Denmark were randomly allocated to intervention (16 schools) or control (15 schools) groups. The study included all first-year students (~ 16 years of age) (n = 5976 students). Timeline: Intervention: August 2016 - June 2017. Collection of questionnaire data: Baseline (August 2016), 1st follow-up (May 2017) and 2nd follow-up (April 2018). All students were invited to participate in a monthly sub-study about perceived stress using text messages for data collection (September 2016 - June 2017). PA was objectively assessed among a sub-sample of students using accelerometers (Axivity, AX3) in August 2016 and May 2017. PRIMARY OUTCOME MEASURES: Student well-being measured by the Cantril Ladder and the five item World Health Organisation Well-being Index (individual level outcomes). SECONDARY OUTCOME MEASURES: Stress (10-item Perceived Stress Scale), sleep (quantity and quality), PA (hours of moderate-to-vigorous PA per week, hours of daily sedentary time and average daily PA), meal habits (daily intake of breakfast, lunch, snacks and water), and strong sense of community in class and at school, respectively (individual level outcomes). The study encompasses process and effect evaluation as well as health economic analyses. TRIAL REGISTRATION: ISRCTN ISRCTN43284296, 28 April 2017, retrospectively registered.

Perinatal outcomes in 521 gestations after fresh and frozen cycles: a secondary outcome of a randomized controlled trial comparing GnRH antagonist versus GnRH agonist protocols.

RESEARCH QUESTION: Are perinatal outcomes different after treatment with the gonadotrophin-releasing hormone (GnRH) antagonist versus the long GnRH agonist protocol for IVF? DESIGN: Perinatal outcomes were secondary outcomes in a large Phase IV, dual-centre, open-label, randomized controlled trial to compare GnRH antagonist and long GnRH agonist protocols in women <40 years undergoing their first assisted reproductive technology treatment. Women (n = 1050) were randomized in a ratio 1:1 from January 2009 to December 2013 and followed until December 2016. All fresh and frozen embryo transfer (FET) cycles from a single oocyte aspiration, resulting in a gestation (human chorionic gonadotrophin >10 IU/l) were included (n = 521). Data were analysed to compare preterm birth [PTB] (<37 weeks), very PTB (<32 weeks), low birthweight [LBW] (<2500 g) and very LBW (<1500 g) rates among singleton live births in GnRH antagonist versus agonist protocol. RESULTS: Similar perinatal outcomes were found after both protocols. In singletons after fresh embryo transfer, mean gestational age at delivery was 39.1 ± 2.49 versus 39.3 ± 1.90 (P = 0.67) and very PTB rates 1.9% versus 0% (P = 0.17). Mean birthweight was 3264 ± 662 g in the antagonist and 3341 ± 562 g in the agonist group (P = 0.37). LBW was found in 12.4% versus 7% (P = 0.19) and very LBW in 2.9% versus 1% (P = 0.34). In FET cycles, the perinatal outcomes were similar. Small for gestational age and large for gestational age rates were similar in both protocols for singleton live births after fresh and FET. CONCLUSIONS: Perinatal outcomes are similar after the GnRH antagonist versus GnRH agonist protocols for IVF. The choice of the GnRH analogue in ovarian stimulation should be based solely on optimizing the chance of pregnancy and not on risks in perinatal outcomes.

Quality of life and psychosocial and physical well-being among 1,023 women during their first assisted reproductive technology treatment: secondary outcome to a randomized controlled trial comparing gonadotropin-releasing hormone (GnRH) antagonist and GnRH agonist protocols.

OBJECTIVE: To compare self-reported quality of life, psychosocial well-being, and physical well-being during assisted reproductive technology (ART) treatment in 1,023 women allocated to either a short GnRH antagonist or long GnRH agonist protocol. DESIGN: Secondary outcome of a prospective phase 4, open-label, randomized controlled trial. Four times during treatment a questionnaire on self-reported physical well-being was completed. Further, a questionnaire on self-reported quality of life and psychosocial well-being was completed at the day of hCG testing. SETTING: Fertility clinics at university hospitals. PATIENT(S): Women referred for their first ART treatment were randomized in a 1:1 ratio and started standardized ART protocols. INTERVENTION(S): Gonadotropin-releasing hormone analogue; 528 women allocated to a short GnRH antagonist protocol and 495 women allocated to a long GnRH agonist protocol. MAIN OUTCOME MEASURE(S): Self-reported quality of life, psychosocial well-being, and physical well-being based on questionnaires developed for women receiving ART treatment. RESULT(S): Baseline characteristics were similar, and response rates were 79.4% and 74.3% in the GnRH antagonist and GnRH agonist groups, respectively. Self-reported quality of life during ART treatment was rated similar and slightly below normal in both groups. However, women in the GnRH antagonist group felt less emotional (adjusted odds ratio [AOR] 0.69), less limited in their everyday life (AOR 0.74), experienced less unexpected crying (AOR 0.71), and rated quality of sleep better (AOR 1.55). Further, women receiving GnRH agonist treatment felt worse physically. CONCLUSION(S): Women in a short GnRH antagonist protocol rated psychosocial and physical well-being during first ART treatment better than did women in a long GnRH agonist protocol. However, the one item on self-reported general quality of life was rated similarly. CLINICAL TRIAL REGISTRATION NUMBER: NCT00756028.

Predictive value of plasma human chorionic gonadotropin measured 14 days after Day-2 single embryo transfer.

INTRODUCTION: Prediction of pregnancy outcome after in vitro fertilization is important for patients and clinicians. Early plasma human chorionic gonadotropin (p-hCG) levels are the best known predictor of pregnancy outcome, but no studies have been restricted to single embryo transfer (SET) of Day-2 embryos. The aim of the present study was to investigate the predictive value of p-hCG measured exactly 14 days after the most commonly used Day-2 SET on pregnancy, delivery, and perinatal outcome. MATERIAL AND METHODS: A retrospective analysis of prospectively collected data on 466 women who had p-hCG measured exactly 14 days after Day-2 SET during a randomized trial including 1050 unselected women (aged 18-40 years) undergoing their first in vitro fertilization/ intracytoplasmic sperm injection treatment. RESULTS: The p-hCG predicted clinical pregnancy [area under the curve (AUC) 0.953; 95% CI 0.915-0.992] significantly better than ongoing pregnancy (AUC 0.803, 95% CI 0.717-0.890) and delivery (AUC 0.772, 95% CI 0.691-0.854). Women with p-hCG levels in the lowest quartile had significantly lower clinical pregnancy, ongoing pregnancy, and delivery rates (p < 0.001), whereas the pregnancy outcome and post-clinical pregnancy loss remained similar throughout the three highest p-hCG quartiles. The p-hCG level was related to neither birthweight nor gestational age at delivery. CONCLUSIONS: Clinical pregnancy is significantly better predicted by p-hCG compared with ongoing pregnancy and delivery. Clinical pregnancy rates, ongoing pregnancy rates, and delivery rates remained similar throughout the three highest p-hCG quartiles with no trend towards "the higher the better".

Schoolyard upgrade in a randomized controlled study design-how are school interventions associated with adolescents' perception of opportunities and recess physical activity.

School recess physical activity is important for adolescent s health and development, and several studies have established evidence based on cross-sectional studies that it is influenced by the environment in the schoolyard. The aim of this study was to investigate the effect and variation across schools of a school-based intervention on students perceived opportunities for physical activity in the schoolyard, and to evaluate if an improved collective perception of opportunities was followed by an increase in PA during recess for the 13-15 year-old students. The intervention components included schoolyard renovation; mandatory outdoor recess; and increased adult supervision and support. Students collective perceptions were evaluated by a newly developed Schoolyard index (SYi) with seven items, and physical activity was objectively measured with accelerometer. We found variations in the change of student perceptions across the intervention schools, and that a one unit increase in the Schoolyard index (SYi) led to a 12% increase in recess PA. This study shows that adolescent PA during recess can be increased through a multicomponent intervention. The prospect for making an impact is low and according to the process analysis dependent on direct involvement; active and supportive adults; and varied, connected and well located facilities.

Correlates of Agreement between Accelerometry and Self-reported Physical Activity.

PURPOSE: Understanding factors that influence accurate assessment of physical activity (PA) and sedentary behavior (SB) is important to measurement development, epidemiologic studies, and interventions. This study examined agreement between self-reported (International Physical Activity Questionnaire-Long Form [IPAQ-LF]) and accelerometry-based estimates of PA and SB across six countries and identified correlates of between-method agreement. METHODS: Self-report and objective (accelerometry-based) PA and SB data were collected in 2002-2011 from 3865 adult participants in eight cities from six countries (Belgium, Czech Republic, Denmark, Spain, United Kingdom, and United States). Between-method relative agreement (correlation) and absolute disagreement (mean difference between conceptually and intensity-matched IPAQ-LF and accelerometry-based PA and SB variables) were estimated. Also, sociodemographic characteristics and PA patterns were examined as correlates of between-method agreement. RESULTS: Observed relative agreement (relationships of IPAQ-LF with accelerometry-based PA and SB variables) was small to moderate (r = 0.05-0.37) and was moderated by sociodemographic (age, sex, weight status, and education) and behavioral (PA-type) factors. The absolute disagreement was large, with participants self-reporting higher PA intensity and total time in moderate-to-vigorous-intensity PA than accelerometry. Also, self-reported sitting time was lower than accelerometry-based sedentary behavior. After adjusting for sociodemographic and behavioral factors, the absolute disagreement between pairs of IPAQ-LF and accelerometry-based PA variables remained significantly different across cities/countries. CONCLUSIONS: Present findings suggest systematic cultural and/or linguistic and sociodemographic differences in absolute agreement between the IPAQ-LF and the accelerometry-based PA and SB variables. These results have implications for the interpretation of international PA and SB data and correlate/determinant studies. They call for further efforts to improve such measures.

Activating schoolyards: study design of a quasi-experimental schoolyard intervention study.

BACKGROUND: The aim of the Activating Schoolyards Study is to develop, implement, document and assess a comprehensive schoolyard intervention to promote physical activity (PA) during school recess for primary school children (grade 4-8). The intervention is designed to implement organizational and structural changes in the physical environment. METHOD: The study builds on a quasi-experimental study design using a mixed method approach including: 1) an exploratory study aimed at providing input for the developing process; 2) an evaluation of the effect of the interventions using a combination of accelerometer, GPS and GIS; 3) a process evaluation facilitating the intervention development process and identifying barriers and facilitators in the implementation process; 4) a post-intervention end-user evaluation aimed at exploring who uses the schoolyards and how the schoolyards are used. The seven project schools (cases) were selected by means of an open competition and the interventions were developed using a participatory bottom-up approach. DISCUSSION: The participatory approach and case selection strategy make the study design novel. The use of a mixed methods design including qualitative as well as quantitative methods can be seen as a strength, as the different types of data complement each other and results of one part of the study informed the following parts. A unique aspect of our study is the use of accelerometers in combination with GPS and GIS in the effect evaluation to objectively determine where and how active the students are in the schoolyard, before and after the intervention. This provides a type of data that, to our knowledge, has not been used before in schoolyard interventions. Exploring the change in behavior in relation to specific intervention elements in the schoolyard will lead to recommendations for schools undergoing schoolyard renovations at some point in the future.