A system dynamics approach to understand Dutch adolescents' sleep health using a causal loop diagram.

BACKGROUND: Healthy sleep is crucial for the physical and mental wellbeing of adolescents. However, many adolescents suffer from poor sleep health. Little is known about how to effectively improve adolescent sleep health as it is shaped by a complex adaptive system of many interacting factors. This study aims to provide insights into the system dynamics underlying adolescent sleep health and to identify impactful leverage points for sleep health promotion interventions. METHODS: Three rounds of single-actor workshops, applying Group Model Building techniques, were held with adolescents (n = 23, 12-15 years), parents (n = 14) and relevant professionals (n = 26). The workshops resulted in a multi-actor Causal Loop Diagram (CLD) visualizing the system dynamics underlying adolescent sleep health. This CLD was supplemented with evidence from the literature. Subsystems, feedback loops and underlying causal mechanisms were identified to understand overarching system dynamics. Potential leverage points for action were identified applying the Action Scales Model (ASM). RESULTS: The resulting CLD comprised six subsystems around the following themes: (1) School environment; (2) Mental wellbeing; (3) Digital environment; (4) Family & Home environment; (5) Health behaviors & Leisure activities; (6) Personal system. Within and between these subsystems, 16 reinforcing and 7 balancing feedback loops were identified. Approximately 60 potential leverage points on different levels of the system were identified as well. CONCLUSIONS: The multi-actor CLD and identified system dynamics illustrate the complexity of adolescent sleep health and supports the need for developing a coherent package of activities targeting different leverage points at all system levels to induce system change.

Qualitative multi-stakeholder evaluation of the adoption, implementation and sustainment of the school-based dietary intervention "Jump-in".

BACKGROUND: Comprehensive school-based programs applying the WHO Health Promoting School Model have the potential to initiate and sustain behavior change and impact health. However, since they often include intervention efforts on a school's policies, physical environment, curriculum, health care and involving parents and communities, they significantly 'intrude' on a complex system that is aimed primarily at education, not health promotion. More insights into and concrete strategies are therefore needed regarding their adoption, implementation, and sustainment processes to address the challenge to sustainable implementation of HPS initiatives in a primarily educational setting. This study consequently evaluates adoption, implementation and sustainment processes of Amsterdam's Jump-in healthy nutrition HPS intervention from a multi-stakeholder perspective. METHODS: We conducted semi-structured interviews and focus groups with all involved stakeholders (n = 131), i.e., Jump-in health promotion professionals (n = 5), school principals (n = 7), at-school Jump-in coordinators (n = 7), teachers (n = 20), parents (n = 50, 9 groups) and children (n = 42, 7 groups) from 10 primary schools that enrolled in Jump-in in the school year 2016-2017. Included schools had a higher prevalence of overweight and/or obesity than the Dutch average and they were all located in Amsterdam's low-SEP neighborhoods. Data were analyzed using a directed content analysis, in which the Determinants of Innovation Model was used for obtaining theory-based predetermined codes, supplemented with new codes emerging from the data. RESULTS: During intervention adoption, all stakeholders emphasized the importance of parental support, and accompanying workshops and promotional materials. Additionally, parents and teachers indicated that a shared responsibility for children's health and nuanced framing of health messages were important. During implementation, all stakeholders needed clear guidelines and support structures. Teachers and children highlighted the importance of peer influence, social norms, and uniform application of guidelines. School staff also found further tailoring of the intervention and dealing with financial constraints important. For long-term intervention sustainment, incorporating the intervention policies into the school statutes was crucial according to health promotion professionals. CONCLUSIONS: This qualitative evaluation provides valuable insights into factors influencing the adoption, implementation, and sustainment processes of dietary interventions, such as the importance of transparent and consistent intervention guidelines, clear communication regarding the rationale behind intervention guidelines, and, stakeholders' involvement in decision-making.

Development of an action programme tackling obesity-related behaviours in adolescents: a participatory system dynamics approach.

System dynamics approaches are increasingly addressing the complexity of public health problems such as childhood overweight and obesity. These approaches often use system mapping methods, such as the construction of causal loop diagrams, to gain an understanding of the system of interest. However, there is limited practical guidance on how such a system understanding can inform the development of an action programme that can facilitate systems changes. The Lifestyle Innovations Based on Youth Knowledge and Experience (LIKE) programme combines system dynamics and participatory action research to improve obesity-related behaviours, including diet, physical activity, sleep and sedentary behaviour, in 10-14-year-old adolescents in Amsterdam, the Netherlands. This paper illustrates how we used a previously obtained understanding of the system of obesity-related behaviours in adolescents to develop an action programme to facilitate systems changes. A team of evaluation researchers guided interdisciplinary action-groups throughout the process of identifying mechanisms, applying the Intervention Level Framework to identify leverage points and arriving at action ideas with aligning theories of change. The LIKE action programme consisted of 8 mechanisms, 9 leverage points and 14 action ideas which targeted the system's structure and function within multiple subsystems. This illustrates the feasibility of developing actions targeting higher system levels within the confines of a research project timeframe when sufficient and dedicated effort in this process is invested. Furthermore, the system dynamics action programme presented in this study contributes towards the development and implementation of public health programmes that aim to facilitate systems changes in practice.

Adolescent sleep duration: associations with social-cognitive determinants and the mediating role of sleep hygiene practices.

Insufficient sleep duration among adolescents is a widespread public health problem. Gaining better insight into social-cognitive determinants associated with adolescent sleep duration is necessary for developing effective preventive interventions to support healthy sleep. This study aimed to explore whether social-cognitive determinants regarding sufficient sleep duration were associated with sleep duration, and if these associations were mediated by collective sleep hygiene practices. Furthermore, we examined these associations for social-cognitive determinants related to not using media before bedtime and doing relaxing activities and considered whether these associations were mediated by specific sleep hygiene practices. Data were collected amongst second- and third-grade adolescents from 10 Dutch high schools. A total of 878 adolescents (mean [SD] age 13.3 [0.71] years) completed data on sleep duration, social-cognitive determinants of the Theory of Planned Behaviour (i.e., attitude, subjective norms from parents, subjective norms from peers, perceived behavioural control, intention), and sleep hygiene practices. Single- and multivariable path models were constructed and mediation by sleep hygiene practices was analysed by Monte Carlo simulation. All social-cognitive determinants except for subjective norms from peers were associated with longer sleep duration (p < 0.01). Sleep hygiene practices mediated all associations between social-cognitive determinants and sleep duration (mediation ranging from 16% to 72%). Although some of the significant associations and mediation disappeared in the multivariable model, behavioural arousal was the strongest mediator, but collective sleep hygiene practices and cognitive/emotional arousal also explained parts of the associations. The findings indicate that social-cognitive factors should not be overlooked when targeting adolescent sleep duration.

The effects of the COVID-19 lockdowns on motor skill development of 6- and 7-year old children in the Netherlands: a longitudinal study.

BACKGROUND: The closing of schools and sports clubs during the COVID-19 lockdown raised questions about the possible impact on children's motor skill development. Therefore, we compared motor skill development over a one-year period among four different cohorts of primary school children of which two experienced no lockdowns during the study period (control cohorts) and two cohorts experienced one or two lockdowns during the study period (lockdown cohorts). METHODS: A total of 992 children from 9 primary schools in Amsterdam (the Netherlands) participated in this study (age 5 - 7; 47.5% boys, 52.5% girls). Their motor skill competence was assessed twice, first in grade 3 (T1) and thereafter in grade 4 (T2). Children in control group 1 and lockdown group 1 were assessed a third time after two years (T3). Motor skill competence was assessed using the 4-Skills Test, which includes 4 components of motor skill: jumping force (locomotion), jumping coordination (coordination), bouncing ball (object control) and standing still (stability). Mixed factorial ANOVA's were used to analyse our data. RESULTS: No significant differences in motor skill development over the study period between the lockdown groups and control groups (p > 0.05) were found, but a difference was found between the two lockdown groups: lockdown group 2 developed significantly better than lockdown group 1 (p = 0.008). While socioeconomic status was an effect modifier, sex and motor ability did not modify the effects of the lockdowns. CONCLUSIONS: The COVID-19 lockdowns in the Netherlands did not negatively affect motor skill development of young children in our study. Due to the complexity of the factors related to the pandemic lockdowns and the dynamic systems involved in motor skill development of children, caution must be taken with drawing general conclusions. Therefore, children's motor skill development should be closely monitored in the upcoming years and attention should be paid to individual differences.

Correlates of inadequate sleep health among primary school children.

The aim of the present study was to explore potential factors of inadequate sleep health (i.e. sleep duration, quality, and timing) of school-aged children. Data were collected among 382 primary school children (aged 4-13 years) and their parents. Personal characteristics (i.e. age, sex), individual lifestyle behaviours (i.e. screen use, sleep hygiene behaviour), social and community factors (i.e. parental sleep-related practices, parental barriers, perceived ethnicity), and living conditions (i.e. parental educational level, sleep environment) were assessed with a parental questionnaire. Sleep duration, quality, and timing were assessed with a sleep diary. Associations were analysed using linear mixed models and logistic regression analyses. In total, 332 children, with a mean (range) age of 7.5 (4-13) years, were included in the analyses. The mean sleep duration was 632 min/night, the mean sleep quality score was 40, on a scale from 10 to 50, and 25% had a bedtime that varied >40 min between weekdays. Factors negatively associated with children's sleep health included older age, perceived non-Dutch cultural background, lower parental pre-sleep emotional support, the parental barrier to get their child to bed on time when siblings have a later bedtime, high parental educational level, sleeping in a darkened bedroom, and being brought to bed after falling asleep. On average, children in the present study had adequate sleep health. The factors found to be associated with children's sleep health are useful for future healthy sleep research and intervention development.

Predictors of Changes in Sleep Duration in Dutch Primary Schoolchildren: the ChecKid Study.

BACKGROUND: Healthy sleep duration is essential to health and well-being in childhood and later life. Unfortunately, recent evidence shows a decline in sleep duration among children. Although effective interventions promoting healthy sleep duration require insight into its predictors, data on these factors are scarce. This study therefore investigated (i) which individual (lifestyle), social and cultural factors, and living conditions and (ii) which changes in these factors might be associated with the changes in sleep duration of Dutch primary schoolchildren observed over time. METHOD: Data from the ChecKid study was used, a dynamic cohort study among 4-13-year-old children living in the city of Zwolle, the Netherlands. Associations between changes in sleep duration and individual (lifestyle) factors (i.e., age, sex, physical activity behavior, sugar-sweetened beverage consumption, screen behavior), social and cultural factors (i.e., parental rules, ethnicity), and living conditions (i.e., parental education, presence of screens in the bedroom, household size) were analyzed using multivariable linear regression. RESULTS: A total of 1180 children participated, aged 6.6 ± 1.4 years in 2009. Mean sleep duration decreased from 11.4 ± 0.5 h/night in 2009 to 11.0 ± 0.5 h/night in 2012. Older children, boys, children who used screens after dinner, children with greater computer/game console use, and children whose parents had low levels of education had a greater decrease in sleep duration. CONCLUSIONS: This article reports on one of the first large, longitudinal cohort studies on predictors of child sleep duration. The results of the study can inform future interventions aimed at promoting healthy sleep in primary schoolchildren.

Independent and sensitive gait parameters for objective evaluation in knee and hip osteoarthritis using wearable sensors.

BACKGROUND: Although it is well-established that osteoarthritis (OA) impairs daily-life gait, objective gait assessments are not part of routine clinical evaluation. Wearable inertial sensors provide an easily accessible and fast way to routinely evaluate gait quality in clinical settings. However, during these assessments, more complex and meaningful aspects of daily-life gait, including turning, dual-task performance, and upper body motion, are often overlooked. The aim of this study was therefore to investigate turning, dual-task performance, and upper body motion in individuals with knee or hip OA in addition to more commonly assessed spatiotemporal gait parameters using wearable sensors. METHODS: Gait was compared between individuals with unilateral knee (n = 25) or hip OA (n = 26) scheduled for joint replacement, and healthy controls (n = 27). For 2 min, participants walked back and forth along a 6-m trajectory making 180° turns, with and without a secondary cognitive task. Gait parameters were collected using 4 inertial measurement units on the feet and trunk. To test if dual-task gait, turning, and upper body motion had added value above spatiotemporal parameters, a factor analysis was conducted. Effect sizes were computed as standardized mean difference between OA groups and healthy controls to identify parameters from these gait domains that were sensitive to knee or hip OA. RESULTS: Four independent domains of gait were obtained: speed-spatial, speed-temporal, dual-task cost, and upper body motion. Turning parameters constituted a gait domain together with cadence. From the domains that were obtained, stride length (speed-spatial) and cadence (speed-temporal) had the strongest effect sizes for both knee and hip OA. Upper body motion (lumbar sagittal range of motion), showed a strong effect size when comparing hip OA with healthy controls. Parameters reflecting dual-task cost were not sensitive to knee or hip OA. CONCLUSIONS: Besides more commonly reported spatiotemporal parameters, only upper body motion provided non-redundant and sensitive parameters representing gait adaptations in individuals with hip OA. Turning parameters were sensitive to knee and hip OA, but were not independent from speed-related gait parameters. Dual-task parameters had limited additional value for evaluating gait in knee and hip OA, although dual-task cost constituted a separate gait domain. Future steps should include testing responsiveness of these gait domains to interventions aiming to improve mobility.

Preparing for an orthopedic consultation using an eHealth tool: a randomized controlled trial in patients with hip and knee osteoarthritis.

BACKGROUND: To evaluate the effect of a stand-alone mobile and web-based educational intervention (eHealth tool) compared to usual preparation of a first orthopedic consultation of patients with hip or knee osteoarthritis (OA) on patients' satisfaction. METHODS: A two-armed randomized controlled trial involving 286 patients with (suspicion of) hip or knee OA, randomly allocated to either receiving an educational eHealth tool to prepare their upcoming consultation (n = 144) or usual care (n = 142). Satisfaction with the consultation on three subscales (range 1-4) of the Consumer Quality Index (CQI - primary outcome) and knowledge (assessed using 22 statements on OA, range 0-22), treatment beliefs (assessed by the Treatment beliefs in OsteoArthritis questionnaire, range 1-5), assessment of patient's involvement in consultation by the surgeon (assessed on a 5-point Likert scale) and patient satisfaction with the outcome of the consultation (numeric rating scale), were assessed. RESULTS: No differences between groups were observed on the 3 subscales of the CQI (group difference (95% CI): communication 0.009 (- 0.10, 0.12), conduct - 0.02 (- 0.12, 0.07) and information provision 0.02 (- 0.18, 0.21)). Between group differences (95% CI) were in favor of the intervention group for knowledge (1.4 (0.6, 2.2)), negative beliefs regarding physical activities (- 0.19 (- 0.37, - 0.002) and pain medication (- 0.30 (- 0.49, - 0.01)). We found no differences on other secondary outcomes. CONCLUSIONS: An educational eHealth tool to prepare a first orthopedic consultation for hip or knee OA does not result in higher patient satisfaction with the consultation, but it does influence cognitions about osteoarthritis. TRIAL REGISTRATION: Dutch Trial Register (trial number NTR6262). Registered 30 January 2017.

Anatomical superficial medial collateral ligament reconstruction with posteromedial capsule reefing successfully restores valgus knee laxity.

The goal of this study was to present the results of an anatomical superficial medial collateral ligament (sMCL) reconstruction combined with reefing of the posteromedial capsule in a series of 10 patients with symptomatic valgus instability complaints in combined injuries of the knee. All patients under- went an sMCL reconstruction with reefing of the posteromedial capsule. If cruciate ligament insuf- ficiency was present, this was reconstructed as well. Pre- and postoperatively, multiple subjective knee outcome scores were obtained, and valgus stress radiographs objectively evaluated laxity. Median valgus laxity of the injured knee on valgus stress radiographs improved significantly. There was no statistically significant difference between post- operative valgus laxity of the injured knee and valgus laxity of the uninjured knee. All subjective knee outcome scores improved significantly compared with the preoperative situation. The described procedure restores valgus laxity to a level comparable to the uninjured knee.

Associations between overweight and mental health problems among adolescents, and the mediating role of victimization.

BACKGROUND: Evidence has not been conclusive on whether adolescent overweight is associated with mental health, possibly caused by indirect, yet untested associations. Therefore, the purpose of this study was to examine the association between overweight or obesity and mental health problems among adolescents, and to determine whether victimization plays a mediating role in these associations. METHODS: Self-reported data on mental health and victimization and objectively measured Body Mass Index data were used, using three cohorts (2010-2011 until 2012-2013) and an interval between the measurement waves of two years later. We performed a multi-level mediation analysis with a two-level structure to incorporate the clustering of the measurements within individuals. The study population consisted of 13,740 secondary school students, 13-14 years old at the first measurement moment, in Amsterdam, the Netherlands. RESULTS: Compared to their normal-weight peers, adolescents with overweight or obesity reported psychosocial problems and suicidal thoughts more often. Victimization was a significant mediator in the relationship between having overweight, and psychosocial problems (indirect effect OR: 2.3; 95% CI 1.5, 3.7 and direct effect OR: 1.4; 95% CI 1.2, 1.7) or suicidal thoughts (indirect effect OR: 2.1; 95% CI 1.4, 3.2 and direct effect OR: 1.3; 95% CI 1.1, 1.5). The associations between obesity, and psychosocial problems (indirect OR: 6.2; 95% CI 2.8, 14.7 and direct effect OR: 1.4; 95% CI 1.0, 2.0), or suicidal thoughts (indirect OR: 4.5; 95% CI 2.3, 9.1 and direct effect OR: 1.5; 95% CI 1.1, 2.0) were even stronger. CONCLUSIONS: Overweight and obesity were significantly associated with mental health problems in adolescents, and victimization played a mediating role in this association. Victimization and mental health should be integrated into prevention programs that address healthy weight development. Moreover, overweight should be given more attention in programs to prevent victimization and promote adolescent mental health.

Preliminary effects of a regional approached multidisciplinary educational program on healthcare utilization in patients with hip or knee osteoarthritis: an observational study.

BACKGROUND: Providing relevant information on disease and self-management helps patients to seek timely contact with care providers and become actively involved in their own care process. Therefore, health professionals from primary care, multiple hospitals and health organisations jointly decided to develop an educational program on osteoarthritis (OA). The objective of the present study was to determine preliminary effects of this OA educational program on healthcare utilization and clinical outcomes. METHODS: We developed an educational group-based program consisting of 2 meetings of 1.5 h, provided by a physiotherapist, a general practitioner (GP) and orthopaedic surgeon or specialized nurse. The program included education on OA, (expectations regarding) treatment options and self-management. Patients were recruited through searching the GPs' electronic patients records and advertisements in local newspapers. At baseline and at 3 months follow-up participating OA patients completed questionnaires. Paired-sample t-tests, McNemar's test and Wilcoxon Signed-Rank test were used to estimate the preliminary effects of the program. RESULTS: A total of 146 participants in 3 districts attended the sessions, of whom 143 agreed to participate in this study; mean age 69.1 years (SD10.2).107 (75%) participants completed both baseline and follow up assessments. The proportion of participants who had visited their GP in the 3 months after the program was lower than 3 months previous to the program (40% versus 25%, p-value 0.01). Also, we observed a decrease in proportion of patients who visited the physio- and exercise therapist, (36.1% versus 25.0%, p-value 0.02). Both illness perceptions and knowledge on OA and treatment options changed positively (Δ-1.8, 95%CI:0.4-3.4, and Δ2.4, 95%CI:-3.0 - -1.6 respectively). No changes in BMI, pain, functioning and self-efficacy were found. However, a trend towards an increase in physical activity was observed. CONCLUSIONS: Our results show that a multidisciplinary educational program may result in a decrease in healthcare utilization and has a positive effect on illness perceptions and knowledge on OA due to clear and consistent information on OA and it treatment options. TRIAL REGISTRATION: Netherlands Trial Register ( NTR5472 ). Registered 22 September 2015.

Interventions that stimulate healthy sleep in school-aged children: a systematic literature review.

Background: Healthy sleep among children has social, physical and mental health benefits. As most of today's children do not meet the healthy sleep recommendations, effective interventions are urgently needed. This systematic review summarizes the characteristics and effectiveness of interventions aiming to stimulate healthy sleeping in a general population of school-aged children. Methods: The search engines PubMed, Embase, Web of Science, PsycInfo and the Cochrane Database Library were systematically searched up to March 2016. We included all studies evaluating interventions targeting healthy sleep duration and/or bedtime routines of children aged 4­12 years. All steps in this systematic review, i.e. search, study selection, quality assessment and data extraction, were performed following CRD Guidelines and reported according to the PRISMA Statement. Results: Eleven studies were included, of which only two were of strong quality. The interventions varied in terms of targeted determinants and intervention setting. Overall, no evidence was found favoring a particular intervention strategy. One intervention that delayed school start time and two multi-behavioral interventions that targeted both the school and home setting showed promising effects in terms of increasing sleep duration. Conclusion: Due to few high quality studies, evidence for the effectiveness of any particular intervention strategy to stimulate healthy sleep in children is still inconclusive. However, the more effective interventions in stimulating healthy sleep duration and adherence to regular bedtimes were mostly multi-behavioral interventions that included creating daily healthy routines and combined intervention settings (e.g. home and school). In conclusion, high-quality studies evaluating systematically developed interventions are needed to move this field forward.

Associations of health behaviors, school performance and psychosocial problems in adolescents in The Netherlands.

School-based health-promoting interventions show promising results in improving various health outcomes of adolescents. Unfortunately, much is still unknown about the relations between health behaviors and school performances, while improving these would give schools a stronger incentive to invest in health promotion. This paper presents the associations of several health behaviors with school performances and studies the mediating effects of psychosocial problems. Health behavior and socio-demographic data were gathered from 905 Dutch high school students via an online survey, completed in-class. These data were matched with school records of the students' overall grade average (GA) on the three core subjects in Dutch high schools (Dutch, English and Math). The associations between health behaviors and school performances, and the potentially mediating effects of psychosocial problems, were studied via mixed-effects regression models. Smoking, being bullied, compulsive and excessive internet use and low physical activity were directly associated with lower school grades. Additionally, being bullied, bullying, smoking, excessive and compulsive internet use were associated with students' grades via mediation of psychosocial problems. This means that lower school grades were (also) associated with those behaviors through the effects of psychosocial problems in those students. This study showed the strong links between health behaviors and academic achievements among adolescents. Schools and health promoters should be educated more on these relations, so that they are aware of this common interest to get more support for health-promoting interventions. Additionally, the role of psychosocial problems in the relations between behaviors and school performances should be studied further in future research.

A Controlled Health Promoting School Study in the Netherlands: Effects After 1 and 2 Years of Intervention.

PURPOSE: Many unhealthy behavioral habits often originate in adolescence. In the literature, the school-based whole school approach is stated be the most promising way to promote healthy behavior. Herein, interventions are evidence based and integrated into the curriculum, while embedded in complementary healthy school policies and environment. This study evaluates the effects of such an intervention on Dutch high schools. METHODS: Two Dutch high schools and two controls were followed to evaluate the intervention's effects on health behaviors, body mass index, and psychosocial problems after 1 year (N = 969) and 2 years (N = 605). Outcomes were measured via self-report surveys and analyzed with mixed methods regression analyses. To complement information on intervention effects, structured interviews were held with a representative sample of teachers per intervention school to map their respective whole school approach implementation success. RESULTS: After 2 years, one intervention school showed significant improvements: Body mass index and excessive screen time use were reduced. In the other intervention school, priority targets did not improve. These findings reflected their respective success in intervention implementation, for example, differences in intervention integration and tailoring. CONCLUSIONS: This study shows that it is feasible for schools to implement a comprehensive Health Promoting School intervention themselves and that, when successful, effects in terms of improving behaviors and health outcomes are promising. The process evaluation helped understand these findings in context.

Unhealthy behaviors in adolescents: multibehavioral associations with psychosocial problems.

BACKGROUND: Several unhealthy behaviors are associated with psychosocial health in adolescents. Previous studies have shown that different adolescent health behaviors cluster, and, in order to understand these associations, it is important to investigate the relations between individual behaviors and psychosocial problems. PURPOSE: This study addressed the research question "Are adolescent health behaviors associated with psychosocial problems, and to what extent do certain health behaviors confound the relations between other health behaviors and psychosocial problems in adolescents?" METHODS: Self-reported questionnaire data on a broad range of health behaviors and demographics were collected from 2,690 high school students in the Netherlands in September 2012. RESULTS: After adjustment for demographic characteristics, nearly all unhealthy behaviors were found to be significantly associated with psychosocial problems. However, after correction for confounding by other behaviors, psychosocial problems were associated with fewer behaviors, namely compulsive internet use and videogame playing, smoking, cannabis use, and being bullied. These associations differed in boys and girls. CONCLUSIONS: In multibehavioral analyses adjusted for behavioral clustering, which can cause considerable interbehavioral confounding, several behaviors were associated with psychosocial problems in adolescents. This approach to behavior analysis provides a better insight into behaviors and psychosocial health, and the specific associations identified can be utilized when designing effective prevention programs, such as health-promoting school interventions.

The Effects of the Jump-In Whole-School Intervention on the Weight Development of Children in Amsterdam, the Netherlands.

BACKGROUND: This study assessed the effects of the "Jump-in" whole-school intervention in Amsterdam, the Netherlands, on children's weight development by comparing children exposed to the intervention and controls from 3 other large Dutch cities. Jump-in is a comprehensive intervention that aims to stimulate healthy nutrition and physical activity in children at primary schools in Amsterdam. In addition, the relationship between the intervention's implementation degree and its effectiveness was studied. METHODS: Demographic and anthropometric data, collected by youth health care professionals via routine health checks at T0 (2014) and T1 (2019), were used to analyze possible intervention effects by comparing the weight development of children exposed to the Jump-in intervention versus unexposed controls. Implementation logs from health promotion professionals were used to determine intervention effects per implementation degree. Multilevel regression analyses were used for all analyses. RESULTS: In total, 4299 children were included mean age ± 5.5 years (T0), 10.6 years (T1), and ≈50% boys/girls at both times. Receiving the fully implemented intervention resulted in a decline in standardized body-mass index (zBMI) compared to the controls (-0.23, confidence interval [CI] -0.33, -0.13). It also led to higher odds to move into a healthier weight category over time (odds ratio [OR] 1.36, CI 1.06, 1.74), yet no statistically significant shift towards a healthy weight was found. CONCLUSIONS: Relative to the controls, children exposed to the intervention showed positive zBMI developments, with stronger effects when the implementation degree was higher. Despite positive results, creating more impact might require the further integration of school-based programs into whole-systems approaches that include other energy-balance behaviors.

Clustering of health-related behaviors, health outcomes and demographics in Dutch adolescents: a cross-sectional study.

BACKGROUND: Recent studies show several health-related behaviors to cluster in adolescents. This has important implications for public health. Interrelated behaviors have been shown to be most effectively targeted by multimodal interventions addressing wider-ranging improvements in lifestyle instead of via separate interventions targeting individual behaviors. However, few previous studies have taken into account a broad, multi-disciplinary range of health-related behaviors and connected these behavioral patterns to health-related outcomes. This paper presents an analysis of the clustering of a broad range of health-related behaviors with relevant demographic factors and several health-related outcomes in adolescents. METHODS: Self-report questionnaire data were collected from a sample of 2,690 Dutch high school adolescents. Behavioral patterns were deducted via Principal Components Analysis. Subsequently a Two-Step Cluster Analysis was used to identify groups of adolescents with similar behavioral patterns and health-related outcomes. RESULTS: Four distinct behavioral patterns describe the analyzed individual behaviors: 1- risk-prone behavior, 2- bully behavior, 3- problematic screen time use, and 4- sedentary behavior. Subsequent cluster analysis identified four clusters of adolescents. Multi-problem behavior was associated with problematic physical and psychosocial health outcomes, as opposed to those exerting relatively few unhealthy behaviors. These associations were relatively independent of demographics such as ethnicity, gender and socio-economic status. CONCLUSIONS: The results show that health-related behaviors tend to cluster, indicating that specific behavioral patterns underlie individual health behaviors. In addition, specific patterns of health-related behaviors were associated with specific health outcomes and demographic factors. In general, unhealthy behavior on account of multiple health-related behaviors was associated with both poor psychosocial and physical health. These findings have significant meaning for future public health programs, which should be more tailored with use of such knowledge on behavioral clustering via e.g. Transfer Learning.

Long-term results of cemented total hip arthroplasty in patients younger than 30 years and the outcome of subsequent revisions.

BACKGROUND: The number of total hip arthroplasties in patients under 30 years is increasing over the years. Almost all of them will face at least one or more future revisions in their life. Therefore, the implant used should have a high survival rate, and needs to be easily revisable resulting in a low re-revision rate. Several studies have evaluated the outcome of total hip arthroplasties in patients under 30 years. However, only a few reported on the follow-up outcome of 10 years or more. In addition, none of these reports published data of the subsequent revisions of these implants within their original report. METHODS: We studied historically prospective collected data of 48 consecutive patients (69 hips) younger than 30 years, treated with a cemented primary total hip prosthesis between 1988 and 2004. Since the last evaluation of this cohort, two patients were lost to follow-up. For all hip revisions in this cohort, again cemented implants were used, mostly in combination with bone impaction grafting. Kaplan-Meier survival curves at 10- and 15 years for the primary total hip arthroplasties and revisions were determined. RESULTS: The mean age at time of primary surgery was 25 years (range, 16 to 29 years). Mean follow-up of the primary hips was 11.5 years (range, 7 to 23 years). During follow-up 13 revisions were performed; in 3 cases a two-stage total revision was performed for septic loosening and 9 cups were revised for aseptic loosening. There were no aseptic stem revisions. The 10 and 15-year survival rates with endpoint revision for aseptic loosening of the primary total hip were 90% (95% CI: 79 to 96) and 82% (95% CI: 65 to 92) respectively. None of our 13 subsequent revisions needed a re-revision within 10 years after re-implantation. CONCLUSIONS: Cemented total hip implants in patients under 30 years have an encouraging outcome at 10 and 15 years after surgery in these young patients. The 13 revised hips, treated with bone grafting and the third generation cement technique, were performing well with no re-revisions within ten years after surgery.