School health promotion and fruit and vegetable consumption in secondary schools: a repeated cross-sectional multilevel study.

BACKGROUND: Worldwide, recommendations for fruit and vegetable consumption are not met, which can cause chronic diseases. Especially adolescence is an important phase for the development of health behaviours. Therefore, in the Netherlands, the Healthy School program was established to aid schools in promoting healthy lifestyles among their students. We examined to what extent the variation between secondary schools regarding students' fruit and vegetable consumption could be explained by differences between schools regarding Healthy School certification, general school characteristics, and the school population. Additionally, we examined whether Healthy School certification was related to the outcomes, and whether the association differed for subgroups. METHODS: We performed a repeated cross-sectional multilevel study. We used data from multiple school years from the national Youth Health Monitor on secondary schools (grades 2 and 4, age ranged from approximately 12 to 18 years) of seven Public Health Services, and added data with regard to Healthy School certification, general school characteristics and school population characteristics. We included two outcomes: the number of days a student consumed fruit and vegetables per week. In total, we analysed data on 168,127 students from 256 secondary schools in the Netherlands. RESULTS: Results indicated that 2.87% of the variation in fruit consumption and 5.57% of the variation in vegetable consumption could be attributed to differences at the school-level. Characteristics related to high parental educational attainment, household income, and educational track of the students explained most of the variance between schools. Additionally, we found a small favourable association between Healthy School certification and the number of days secondary school students consumed fruit and vegetables. CONCLUSIONS: School population characteristics explained more variation between schools than Healthy School certification and general school characteristics, especially indicators of parental socioeconomic status. Nevertheless, Healthy School certification seemed to be slightly related to fruit and vegetable consumption, and might contribute to healthier dietary intake. We found small differences for some subgroups, but future research should focus on the impact in different school contexts, since we were restricted in the characteristics that could be included in this study.

A study on the applicability of the Strengths and Difficulties Questionnaire among low- and higher-educated adolescents.

Aim: The Strengths and Difficulties Questionnaire self-report (SDQ-SR) is a valid instrument for detection of emotional and behavioral problems. The aim of this study was to compare the psychometric properties of the SDQ-SR for low and higher educated adolescents, and to explore its suitability. Methods: We included 426 adolescents. We compared internal consistency for low-educated, i.e., at maximum pre-vocational secondary education, and higher educated adolescents and assessed whether the five-factor structure of the SDQ holds across educational levels. We also interviewed 24 low-educated adolescents, and 17 professionals. Results: On most SDQ subscales the low-educated adolescents had more problematic mean scores than the higher educated adolescents. Findings on the invariance factor analyses were inconsistent, with some measures showing a bad fit of the five factor model, and this occurring relatively more for the low-educated adolescents. Professionals and adolescents reported that the SDQ included difficult wordings. Discussion: Our findings imply that the scale structure of the SDQ-SR is slightly poorer for low educated adolescents. Given this caveat, psychometric properties of the SDQ-SR are generally sufficient for use, regardless of educational level.

Computerized adaptive testing to screen pre-school children for emotional and behavioral problems.

Questionnaires to detect emotional and behavioral (EB) problems in preventive child healthcare (PCH) should be short; this potentially affects their validity and reliability. Computerized adaptive testing (CAT) could overcome this weakness. The aim of this study was to (1) develop a CAT to measure EB problems among pre-school children and (2) assess the efficiency and validity of this CAT. We used a Dutch national dataset obtained from parents of pre-school children undergoing a well-child care assessment by PCH (n = 2192, response 70%). Data regarded 197 items on EB problems, based on four questionnaires, the Strengths and Difficulties Questionnaire (SDQ), the Child Behavior Checklist (CBCL), the Ages and Stages Questionnaire: Social Emotional (ASQ:SE), and the Brief Infant-Toddler Social and Emotional Assessment (BITSEA). Using 80% of the sample, we calculated item parameters necessary for a CAT and defined a cutoff for EB problems. With the remaining part of the sample, we used simulation techniques to determine the validity and efficiency of this CAT, using as criterion a total clinical score on the CBCL. Item criteria were met by 193 items. This CAT needed, on average, 16 items to identify children with EB problems. Sensitivity and specificity compared to a clinical score on the CBCL were 0.89 and 0.91, respectively, for total problems; 0.80 and 0.93 for emotional problems; and 0.94 and 0.91 for behavioral problems.    Conclusion: A CAT is very promising for the identification of EB problems in pre-school children, as it seems to yield an efficient, yet high-quality identification. This conclusion should be confirmed by real-life administration of this CAT. What is Known: • Studies indicate the validity of using computerized adaptive test (CAT) applications to identify emotional and behavioral problems in school-aged children. • Evidence is as yet limited on whether CAT applications can also be used with pre-school children. What is New: • The results of this study show that a computerized adaptive test is very promising for the identification of emotional and behavior problems in pre-school children, as it appears to yield an efficient and high-quality identification.

Behavior Change Techniques That Prevent or Decrease Obesity in Youth With a Low Socioeconomic Status: A Systematic Review and Meta-Analysis.

Background: Interventions, targeting youth, are necessary to prevent obesity later in life. Especially youth with low socioeconomic status (SES) are vulnerable to develop obesity. This meta-analysis examines the effectiveness of behavioral change techniques (BCTs) to prevent or reduce obesity among 0 to 18-year-olds with a low SES in developed countries. Method: Intervention studies were identified from systematic reviews or meta-analyses published between 2010 and 2020 and retrieved from PsycInfo, Cochrane systematic review, and PubMed. The main outcome was body mass index (BMI), and we coded the BCTs. Results: Data from 30 studies were included in the meta-analysis. The pooled postintervention effects of these studies indicated a nonsignificant decrease in BMI for the intervention group. Longer follow-up (≥12 months) showed favorable differences for intervention studies, although that BMI change was small. Subgroup analyses showed larger effects for studies with six or more BCTs. Furthermore, subgroup analyses showed a significant pooled effect in favor of the intervention for the presence of a specific BCT (problem-solving, social support, instruction on how to perform the behavior, identification of self as role model, and demonstration of the behavior), or absence of a specific BCT (information about health consequences). The intervention program duration and age group of the study population did not significantly influence the studies' effect sizes. Conclusions: Generally, the effects of interventions on BMI change among youth with low SES are small to neglectable. Studies with more than six BCTs and/or specific BCTs had a higher likelihood of decreasing BMI of youth with low SES.

Key developmental milestones helped to identify children with special educational needs and disabilities at an early stage.

AIM: Responding to developmental delay promptly is important, as it helps children to reach their full potential. This study investigated how developmental milestones predicted primary school children with special educational needs and disabilities (SEND) at an early stage. METHODS: We obtained data about 36 milestones between 12 and 45 months using the Dutch Development Instrument. Development, primary school classification and background characteristics were collected from the Dutch Preventive Child Healthcare system in Utrecht from 2008 to 2016. We investigated SEND classifications and the primary schools that the children attended at 4-12 years of age. The findings include area under the curve (AUC) data. RESULTS: Data on 30 579 children in mainstream schools and 1055 children with SEND were available. Different milestones predicted SEND classifications. Fourteen milestones and parental education predicted attendance at special needs schools with smaller classes (AUC 0.913). Nine milestones, sex, migration background and parental education predicted attendance at schools for severe communication problems (AUC 0.963). Ten milestones and parental education predicted attendance at schools for severe learning difficulties (AUC 0.995). Milestones did not accurately predict attendance at schools for severe behavioural or psychiatric problems. CONCLUSION: Milestones at 12-45 months predicted most SEND classifications at primary school age, except severe behavioural or psychiatric problems.

School health promotion and the consumption of water and sugar-sweetened beverages in secondary schools: a cross-sectional multilevel study.

BACKGROUND: Overweight among adolescents remains a serious concern worldwide and can have major health consequences in later life, such as cardiovascular diseases and cancer. Still, 33% of secondary school adolescents in the Netherlands consume sugar-sweetened beverages daily and over 26% do not consume water every day. The Dutch Healthy School program was developed to support schools in stimulating healthier lifestyles by focusing on health education, school environments, identifying students' health problems, and school policy. We examined the variation between secondary schools regarding the daily consumption of water and sugar-sweetened beverages and whether this variation can be explained by differences between schools regarding Healthy School certification, general school characteristics, and the school population. METHODS: We performed a cross-sectional multilevel study. We used data from the national Youth Health Monitor of 2019 on secondary schools (grades 8 and 10, age range about 12 to 18 years) of seven Public Health Services and combined these with information regarding Healthy School certification and general school- and school population characteristics. Our outcomes were daily consumption of water and sugar-sweetened beverages. In total, data from 51,901 adolescents from 191 schools were analysed. We calculated the intraclass correlation to examine the variation between schools regarding our outcomes. Thereafter, we examined whether we could explain this variation by the included characteristics. RESULTS: The school-level explained 4.53% of the variation in the consumption of water and 2.33% of the variation in the consumption of sugar-sweetened beverages. This small variation in water and sugar-sweetened consumption could not be explained by Healthy School certification, yet some general school- and school population characteristics did: the proportion of the school population with at least one parent with high educational attainment, the educational track of the adolescents, urbanicity (only for water consumption) and school type (only for sugar-sweetened beverages consumption). CONCLUSIONS: The low percentages of explained variation indicate that school-level characteristics in general (including Healthy School certification) do not matter substantially for the daily consumption of water and sugar-sweetened beverages. Future research should examine whether school health promotion can contribute to healthier lifestyles, and if so, under which level of implementation and school conditions.

Studies on Reliability and Measurement Error of Measurements in Medicine - From Design to Statistics Explained for Medical Researchers.

Reliability and measurement error are measurement properties that quantify the influence of specific sources of variation, such as raters, type of machine, or time, on the score of the individual measurement. Several designs can be chosen to assess reliability and measurement error of a measurement. Differences in design are due to specific choices about which sources of variation are varied over the repeated measurements in stable patients, which potential sources of variation are kept stable (ie, restricted), and about whether or not the entire measurement instrument (or measurement protocol) was repeated or only part of it. We explain how these choices determine how intraclass correlation coefficients and standard errors of measurement formulas are built for different designs by using Venn diagrams. Strategies for improving the measurement are explained, and recommendations for reporting the essentials of these studies are described. We hope that this paper will facilitate the understanding and improve the design, analysis, and reporting of future studies on reliability and measurement error of measurements.

The impact of occupational exposures on infection rates during the COVID-19 pandemic: a test-negative design study with register data of 207 034 Dutch workers.

OBJECTIVE: This study aimed to investigate the effects of occupational exposures on the risk of a positive COVID-19 test, and whether this differed across pandemic waves. METHODS: Data from 207 034 workers from The Netherlands with test data on COVID-19 from June 2020 until August 2021 were available. Occupational exposure was estimated by using the eight dimensions of a COVID-19 job exposure matrix (JEM). Personal characteristics, household composition and residence area were derived from Statistics Netherlands. A test-negative design was applied in which the risk of a positive test was analyzed in a conditional logit model. RESULTS: All eight dimensions of occupational exposure included in the JEM increased the odds of a positive test for the entire study period and three pandemic waves [OR ranging from 1.09, (95% confidence interval (CI) 1.02-1.17) to 1.77 (95% CI 1.61-1.96)]. Adjusting for a previous positive test and other covariates strongly reduced the odds to be infected, but most dimensions remained at elevated risk. Fully adjusted models showed that contaminated work spaces and face covering were mostly relevant in the first two pandemic waves, whereas income insecurity showed higher odds in the third wave. Several occupations have a higher predicted value for a positive COVID-19 test, with variation over time. Discussion Occupational exposures are associated with a higher risk of a positive test, but variations over time exist in occupations with the highest risks. These findings provide insights for interventions among workers for future pandemic waves of COVID-19 or other respiratory epidemics.

The creation of the Global Scales for Early Development (GSED) for children aged 0-3 years: combining subject matter expert judgements with big data.

INTRODUCTION: With the ratification of the Sustainable Development Goals, there is an increased emphasis on early childhood development (ECD) and well-being. The WHO led Global Scales for Early Development (GSED) project aims to provide population and programmatic level measures of ECD for 0-3 years that are valid, reliable and have psychometrically stable performance across geographical, cultural and language contexts. This paper reports on the creation of two measures: (1) the GSED Short Form (GSED-SF)-a caregiver reported measure for population-evaluation-self-administered with no training required and (2) the GSED Long Form (GSED-LF)-a directly administered/observed measure for programmatic evaluation-administered by a trained professional. METHODS: We selected 807 psychometrically best-performing items using a Rasch measurement model from an ECD measurement databank which comprised 66 075 children assessed on 2211 items from 18 ECD measures in 32 countries. From 766 of these items, in-depth subject matter expert judgements were gathered to inform final item selection. Specifically collected were data on (1) conceptual matches between pairs of items originating from different measures, (2) developmental domain(s) measured by each item and (3) perceptions of feasibility of administration of each item in diverse contexts. Prototypes were finalised through a combination of psychometric performance evaluation and expert consensus to optimally identify items. RESULTS: We created the GSED-SF (139 items) and GSED-LF (157 items) for tablet-based and paper-based assessments, with an optimal set of items that fit the Rasch model, met subject matter expert criteria, avoided conceptual overlap, covered multiple domains of child development and were feasible to implement across diverse settings. CONCLUSIONS: State-of-the-art quantitative and qualitative procedures were used to select of theoretically relevant and globally feasible items representing child development for children aged 0-3 years. GSED-SF and GSED-LF will be piloted and validated in children across diverse cultural, demographic, social and language contexts for global use.

Longitudinal individual predictions from irregular repeated measurements data.

Intensive longitudinal data can be used to explore important associations and patterns between various types of inputs and outcomes. Nonlinear relations and irregular measurement occasions can pose problems to develop an accurate model for these kinds of data. This paper focuses on the development, fitting and evaluation of a prediction model with irregular intensive longitudinal data. A three-step process for developing a prediction tool for (daily) monitoring and prediction is outlined and illustrated for intensive weight measurements in piglets. Step 1 addresses a nonlinear relation in the data by developing and applying a normalizing transformation. Step 2 addresses the intermittent nature of the time points by aligning the measurement times to a common time grid with a broken-stick model. Step 3 addresses the prediction problem by selecting and evaluating inputs and covariates in the model to obtain accurate predictions. The final model predicts future outcomes accurately, while allowing for nonlinearities between input and output and for different measurement histories of individuals. The methodology described can be used to develop a tool to deal with intensive irregular longitudinal data that uses the available information in an optimal way. The resulting tool demonstrated to perform well for piglet weight prediction and can be adapted to many different applications.

Protocol for validation of the Global Scales for Early Development (GSED) for children under 3 years of age in seven countries.

INTRODUCTION: Children's early development is affected by caregiving experiences, with lifelong health and well-being implications. Governments and civil societies need population-based measures to monitor children's early development and ensure that children receive the care needed to thrive. To this end, the WHO developed the Global Scales for Early Development (GSED) to measure children's early development up to 3 years of age. The GSED includes three measures for population and programmatic level measurement: (1) short form (SF) (caregiver report), (2) long form (LF) (direct administration) and (3) psychosocial form (PF) (caregiver report). The primary aim of this protocol is to validate the GSED SF and LF. Secondary aims are to create preliminary reference scores for the GSED SF and LF, validate an adaptive testing algorithm and assess the feasibility and preliminary validity of the GSED PF. METHODS AND ANALYSIS: We will conduct the validation in seven countries (Bangladesh, Brazil, Côte d'Ivoire, Pakistan, The Netherlands, People's Republic of China, United Republic of Tanzania), varying in geography, language, culture and income through a 1-year prospective design, combining cross-sectional and longitudinal methods with 1248 children per site, stratified by age and sex. The GSED generates an innovative common metric (Developmental Score: D-score) using the Rasch model and a Development for Age Z-score (DAZ). We will evaluate six psychometric properties of the GSED SF and LF: concurrent validity, predictive validity at 6 months, convergent and discriminant validity, and test-retest and inter-rater reliability. We will evaluate measurement invariance by comparing differential item functioning and differential test functioning across sites. ETHICS AND DISSEMINATION: This study has received ethical approval from the WHO (protocol GSED validation 004583 20.04.2020) and approval in each site. Study results will be disseminated through webinars and publications from WHO, international organisations, academic journals and conference proceedings. REGISTRATION DETAILS: Open Science Framework https://osf.io/ on 19 November 2021 (DOI 10.17605/OSF.IO/KX5T7; identifier: osf-registrations-kx5t7-v1).

Measuring Implementation of Health Promoting School (HPS) Programs: Development and Psychometric Evaluation of the HPS Implementation Questionnaire.

BACKGROUND: Implementation of Health Promoting School (HPS) programs can be challenging due to the dynamic school context. Navigating between program fidelity and adaptation, as well as integrating the program, is essential for successful implementation, and consequently, for program effects. As part of an evaluation study in the Netherlands, this study aimed to develop a measurement instrument that differentiates schools according to fidelity, adaptation, and integration of HPS implementation. METHODS: This study presents the development and psychometric evaluation of the 28-item HPS Implementation Questionnaire, covering 7 dimensions: adherence, dose, participant responsiveness, quality of delivery, program differentiation, adaptation, and integration. The questionnaire, to be filled out by school employees, was developed for primary, secondary, secondary vocational, and special needs education, in close collaboration with experts (n = 54) in school health promotion. RESULTS: Semi-structured interviews aimed at dimension clarification resulted in a list of 58 items. Items were revised, combined, and/or removed based on quantitative and qualitative feedback by the evaluation study's Community of Practice, 2-round expert consultation, and pre-tests. Psychometric evaluation (n = 535 schools), consisting of calculating Cronbach's α and confirmatory factor analysis (CFA), confirmed internal consistency (α > .72) and the 7-dimension framework. CONCLUSION: The brief yet comprehensive HPS Implementation Questionnaire offers possibilities for research into HPS implementation in various educational sectors and contexts, as well as self-monitoring by individual schools. This study provides first evidence for internal consistency and validity of the questionnaire.

Improved adjusted minimal important change took reliability of transition ratings into account.

OBJECTIVES: The anchor-based minimal important change (MIC), based on the receiver operating characteristic (ROC) analysis or predictive modeling, is biased by the proportion of improved patients. The adjusted MIC, published in 2017, adjusts the predictive MIC for this bias but does not take the reliability of the transition ratings (i.e., the anchor) into account. The aim of this study was to examine whether the transition ratings reliability affects the accuracy of the adjusted MIC and, if so, whether the adjustment can be improved. STUDY DESIGN AND SETTING: Multiple simulations of patient samples involved in anchor-based MIC studies with different characteristics of patient-reported outcome scores were used to determine the impact of reliability of the transition ratings on the MIC estimate. An improved adjustment formula was derived in an exploration set of simulated samples (number of samples = 19,440) and validated in a different set of simulated samples (number of samples = 12,960). The effect of sample size (100-1,000) was also evaluated in simulated datasets. RESULTS: Reliability of the transition ratings biased the MIC estimate if the proportion improved was different from 0.5. The improved adjustment formula performed well, especially if the proportion improved was between 0.3 and 0.7. Smaller sample sizes were at the expense of the precision of the MIC estimates. CONCLUSION: We provide an improved formula for calculating the adjusted MIC, taking into account the proportion of improved patients and the reliability of the transition ratings.

The Strengths and Difficulties Questionnaire Parent Form: Dutch norms and validity.

OBJECTIVE: This study provides Dutch national norms for the parent-reported Strengths and Difficulties Questionnaire (SDQ) for children aged 3-14 years, and assesses the test performance of the SDQ Total Difficulties Scale (TDS) and impairment Scale. We further compared Dutch SDQ norms with those of the United Kingdom (UK), to determine potential variation in country-specific norms. STUDY DESIGN: We analyzed data of 3384 children aged 3 to 14 years. The data were obtained in schools, and in the context of Preventive Child Healthcare. Parents completed the SDQ parent form and the Child Behavior Checklist (CBCL). We determined clinical (10% elevated scores) and borderline (20% elevated scores) SDQ TDS norms. We assessed the test performance (validity) of the SDQ TDS and Impairment Score using the CBCL as criterion. RESULTS: The clinical SDQ TDS norms varied between > 10 and > 14 depending on the age group. The SDQ TDS discriminated between children with and without problems, as measured by the CBCL, for all age groups (AUCs varied from 0.92 to 0.96). The SDQ Impairment Score had added value (beyond the SDQ TDS) only for the age group 12-14 years. For the Netherlands we found lower clinical SDQ TDS norms than those previously reported for the UK (i.e. > 16). CONCLUSION: The clinical SDQ TDS norms varied between > 10 and > 14 depending on the age groups. We found good test performance at these proposed norms. Dutch norms differed somewhat from UK norms. In the Netherlands, the SDQ performed better with Dutch-specific norms than with UK-specific norms.

Development and psychometric evaluation of the CO-PARTNER tool for collaboration and parent participation in neonatal care.

BACKGROUND: Active parent participation in neonatal care and collaboration between parents and professionals during infant hospitalization in the neonatal intensive care unit (NICU) is beneficial for infants and their parents. A tool is needed to support parents and to study the effects and implementation of parent-partnered models of neonatal care. METHODS: We developed and psychometrically evaluated a tool measuring active parent participation and collaboration in neonatal care within six domains: Daily Care, Medical Care, Acquiring Information, Parent Advocacy, Time Spent with Infant and Closeness and Comforting the Infant. Items were generated in focus group discussions and in-depth interviews with professionals and parents. The tool was completed at NICU-discharge by 306 parents (174 mothers and 132 fathers) of preterm infants. Subsequently, we studied structural validity with confirmatory factor analysis (CFA), construct validity, using the Average Variance Extracted and Heterotrait-Monotrait ratio of correlations, and hypothesis testing with correlations and univariate linear regression. For internal consistency we calculated composite reliability (CR). We performed multiple imputations by chained equations for missing data. RESULTS: A 31 item tool for parent participation and collaboration in neonatal care was developed. CFA revealed high factor loadings of items within each domain. Internal consistency was 0.558 to 0.938. Convergent validity and discriminant validity were strong. Higher scores correlated with less parent depressive symptoms (r = -0.141, 95%CI -0.240; -0.029, p = 0.0141), less impaired parent-infant bonding (r = -0.196, 95%CI -0.302; -0.056, p<0.0001), higher parent self-efficacy (r = 0.228, 95%CI 0.117; 0.332, p<0.0001), and higher parent satisfaction (r = 0.197, 95%CI 0.090; 0.308, p = 0.001). Parents in a family integrated care model had higher scores than in standard care (beta 6.020, 95%CI 4.144; 7.895, p<0.0001) and mothers scored higher than fathers (beta 2.103,95%CI 0.084; 4.121, p = 0.041). CONCLUSION: The CO-PARTNER tool explicitly measures parents' participation and collaboration with professionals in neonatal care incorporating their unique roles in care provision, leadership, and connection to their infant. The tool consists of 31 items within six domains with good face, content, construct and structural validity.

Costs and effects of conventional vision screening and photoscreening in the Dutch preventive child health care system.

BACKGROUND: Little is known about costs and effects of vision screening strategies to detect amblyopia. Aim of this study was to compare costs and effects of conventional (optotype) vision screening, photoscreening or a combination in children aged 3-6 years. METHODS: Population-based, cross-sectional study in preventive child health care in The Hague. Children aged 3 years (3y), 3 years and 9 months (3y9m) or 5-6 years (5/6y) received the conventional chart vision screening and a test with a photoscreener (Plusoptix S12C). Costs were based on test duration and additional costs for devices and diagnostic work-up. RESULTS: Two thousand, one hundred and forty-four children were included. The estimated costs per child screened were €17.44, €20.37 and €6.90 for conventional vision screening at 3y, 3y9m and 5/6y, respectively. For photoscreening, these estimates were €6.61, €7.52 and €9.40 and for photoscreening followed by vision screening if the result was unclear (combination) €9.32 (3y) and €9.33 (3y9m). The number of children detected with amblyopia by age were 9, 14 and 5 (conventional screening), 6, 13 and 3 (photoscreening) and 10 (3y) and 15 (3y9m) (combination), respectively. The estimated costs per child diagnosed with amblyopia were €1500, €1050 and €860 for conventional vision screening, €860, €420 and €1940 for photoscreening and €730 (3y) and €450 (3y9m) for the combination. CONCLUSIONS: Combining photoscreening with vision screening seems promising to detect amblyopia in children aged 3y/3y9m, whereas conventional screening seems preferable at 5/6y. As the number of study children with amblyopia is small, further research on the effects of these screening alternatives in detecting children with amblyopia is recommended.

Correction: Effectiveness of a Web-Based Tailored Intervention With Virtual Assistants Promoting the Acceptability of HPV Vaccination Among Mothers of Invited Girls: Randomized Controlled Trial.

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The D-score: a metric for interpreting the early development of infants and toddlers across global settings.

INTRODUCTION: Early childhood development can be described by an underlying latent construct. Global comparisons of children's development are hindered by the lack of a validated metric that is comparable across cultures and contexts, especially for children under age 3 years. We constructed and validated a new metric, the Developmental Score (D-score), using existing data from 16 longitudinal studies. METHODS: Studies had item-level developmental assessment data for children 0-48 months and longitudinal outcomes at ages >4-18 years, including measures of IQ and receptive vocabulary. Existing data from 11 low-income, middle-income and high-income countries were merged for >36 000 children. Item mapping produced 95 'equate groups' of same-skill items across 12 different assessment instruments. A statistical model was built using the Rasch model with item difficulties constrained to be equal in a subset of equate groups, linking instruments to a common scale, the D-score, a continuous metric with interval-scale properties. D-score-for-age z-scores (DAZ) were evaluated for discriminant, concurrent and predictive validity to outcomes in middle childhood to adolescence. RESULTS: Concurrent validity of DAZ with original instruments was strong (average r=0.71), with few exceptions. In approximately 70% of data rounds collected across studies, DAZ discriminated between children above/below cut-points for low birth weight (<2500 g) and stunting (-2 SD below median height-for-age). DAZ increased significantly with maternal education in 55% of data rounds. Predictive correlations of DAZ with outcomes obtained 2-16 years later were generally between 0.20 and 0.40. Correlations equalled or exceeded those obtained with original instruments despite using an average of 55% fewer items to estimate the D-score. CONCLUSION: The D-score metric enables quantitative comparisons of early childhood development across ages and sets the stage for creating simple, low-cost, global-use instruments to facilitate valid cross-national comparisons of early childhood development.

Educational inequalities in the impact of chronic diseases on exit from paid employment among older workers: a 7-year prospective study in the Netherlands.

OBJECTIVES: The study aimed to investigate the relative and absolute risks of early exit from paid employment among older workers with a chronic disease, and to assess whether these risks differ across educational groups. METHODS: Data on chronic diseases and demographics from 9160 Dutch workers aged 45-64 years were enriched with monthly information on employment status from Statistics Netherlands. Subdistribution hazard ratios (SHR) and 7-year probabilities among workers with a chronic disease of exit from paid employment through disability benefits, unemployment benefits, early retirement benefits or economic inactivity were estimated using competing risks regression analyses based on Fine and Gray's models. RESULTS: Workers with one chronic disease had a higher risk to exit paid employment through disability benefits (SHR 4.48 (95%CI 3.22 to 6.25)) compared with workers without chronic disease, and this risk further increased for multiple chronic diseases (SHR 8.91 (95%CI 6.33 to 12.55)). As occurrence of chronic diseases was highest among low educated workers, the 7-year probabilities to exit paid employment through disability benefits were highest among this group. Cardiovascular, musculoskeletal, psychological and respiratory diseases were associated with disability benefits (SHRs ranging from 2.11 (95%CI 1.45 to 3.07) to 3.26 (95%CI 2.08 to 5.12)), whereas psychological diseases were also related to unemployment (SHR 1.78 (95%CI 1.33 to 2.38)). CONCLUSIONS: Older workers with a chronic disease have a higher risk to exit paid employment through disability benefits. As multimorbidity has an additive effect, addressing multimorbidity as a risk factor for sustainable employment is needed.