Stef van Buuren

Nederlandse Organisatie voor Wetenschappelijk Onderzoek, 's-Gravenhage, South Holland, Netherlands

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Publications (181)369.64 Total impact

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    Gerko Vink · Goran Lazendic · Stef Van Buuren

    Full-text · Article · Dec 2015 · Psychological Test and Assessment Modeling
  • Stef van Buuren · Diederik J.D. Wijnmalen

    No preview · Article · Sep 2015 · Journal of applied measurement
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    ABSTRACT: In preterm infants, poor postnatal growth is associated with adverse neuro-cognitive outcomes; conversely rapid postnatal growth is supposedly harmful for future development of metabolic diseases. In this systematic review, observational studies reported consistent positive associations between postnatal weight or head growth and neuro-cognitive outcomes, however there was limited evidence from the few intervention studies. Evidence linking postnatal weight gain to later adiposity and other cardiovascular disease risk factors in preterm infants was also limited. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Full-text · Article · Jul 2015 · Acta Paediatrica
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    ABSTRACT: Curve matching is a new big data technique to predict an outcome given earlier measurements. Here we apply curve matching to predict the future growth of a specific child, the target child. The method searches in large datasets of longitudinal growth data for other children who are similar to the target child in terms of factors that influence growth. The observed growth curves of these matched children provide valuable insights into the future growth of the target child. The TNO Groeivoorspeller (TNO Growth Predictor) plots the expected growth of the target child, as well as the uncertainty of the prediction. Curve matching is a general technique that can also be used for other health measures. The key requirement is the availability of relevant longitudinal data on the outcome and its determinants.
    Full-text · Article · Jul 2015 · Nederlands tijdschrift voor geneeskunde
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    ABSTRACT: Objectives To reanalyze the between-population variance in height, weight, and body mass index (BMI), and to provide a globally applicable technique for generating synthetic growth reference charts.Methods Using a baseline set of 196 female and 197 male growth studies published since 1831, common factors of height, weight, and BMI are extracted via Principal Components separately for height, weight, and BMI. Combining information from single growth studies and the common factors using in principle a Bayesian rationale allows for provision of completed reference charts.ResultsThe suggested approach can be used for generating synthetic growth reference charts with LMS values for height, weight, and BMI, from birth to maturity, from any limited set of height and weight measurements of a given population.Conclusion Generating synthetic growth reference charts by incorporating information from a large set of reference growth studies seems suitable for populations with no autochthonous references at hand yet. Am. J. Hum. Biol., 2015. © 2015 Wiley Periodicals, Inc.
    No preview · Article · Jun 2015 · American Journal of Human Biology
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    Full-text · Dataset · May 2015
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    ABSTRACT: Objectives To study trends in height of Turkish and Moroccan immigrant children living in The Netherlands, to investigate the association between height and background characteristics in these children, and to calculate height-for-age-references data for these groups. Design Nationwide cross-sectional data collection from children aged 0 to 18 years by trained professionals in 1997 and 2009. The study population consisted of 2,822 Turkish 2,779 Moroccan, and 13,705 Dutch origin children in 1997and 2,548 Turkish, 2,594 Moroccan, and 11,255 Dutch origin children in 2009. Main outcome measures: Mean height in cm, and mean height standard deviation scores. Results In 2009, mean height at the age of 18y was similar for Turkish and Moroccan children: 177 cm for boys and 163 cm for girls, which was 2 to 3 cm taller than in 1997. Still, Turkish and Moroccan adolescents were 5.5 cm (boys) to 7 cm (girls) shorter than their Dutch peers. No significant differences were found in mean height standard deviation scores across the educational level of the parents, geographical region, primary language spoken at home, and immigrant generation. Conclusions While the secular height increase in Dutch children came to a halt, the trend in Turkish and Moroccan children living in The Netherlands continued. However, large differences in height between Turkish and Moroccan children and Dutch children remain. We found no association with the background characteristics. We recommend the use of the new growth charts for children of Turkish and Moroccan origin who have a height-for-age below -2SD on the growth chart for Dutch children.
    Full-text · Article · May 2015 · PLoS ONE
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    ABSTRACT: Monitoring overweight in risk groups is necessary. Our aim is to assess the trend in overweight and obesity in Turkish and Moroccan children in the Netherlands since 1997 and to monitor the levels of lifestyle-related behaviours in 2009. We selected cross-sectional data of Turkish and Moroccan children aged 2-18 years from two national Growth Studies performed in 1997 and 2009 in the Netherlands. Lifestyle-related behaviours were obtained in the 2009 study by questionnaire. In 2009, 31.9% of Turkish and 26.6% of Moroccan children had overweight, whereas this was, respectively, 26.7% and 19.6% in 1997. Already at 2 years, 21.1% in Turkish and 22.7% in Moroccan children had overweight in 2009. The prevalence of obesity was above 4% from 3 years onwards. High (i.e. ≥25%) prevalence rates of unhealthy lifestyle-related behaviours were found for not having breakfast (26-49%) among Turkish and Moroccan adolescent (i.e. 15-18 years) girls, consuming no fruit (29-45%) and watching TV/PC ≥2 h (35-72%) among all Turkish and Moroccan adolescents, no walking/cycling to school/day care among preschool children (2-4 years) (28-56%) and adolescents (34-94%), drinking ≥2 glasses of sweet beverages (44-74%) and being <1 h physically active (29-65%) among all children. An upward trend of overweight and obesity occurred in Turkish and Moroccan children. Already at 2 years of age, one out of five Turkish and Moroccan children had overweight, which calls for early prevention with attention to specific lifestyle-related behaviours. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.
    Full-text · Article · Apr 2015 · The European Journal of Public Health
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    ABSTRACT: Introduction Lifestyle Triple P is a general parenting intervention which focuses on preventing further excessive weight gain in overweight and obese children. The objective of the current study was to assess the effectiveness of the Lifestyle Triple P intervention in the Netherlands. Method We used a parallel randomized controlled design to test the effectiveness of the intervention. In total, 86 child-parent triads (children 4-8 years old, overweight or obese) were recruited and randomly assigned (allocation ratio 1:1) to the Lifestyle Triple P intervention or the control condition. Parents in the intervention condition received a 14-week intervention consisting of ten 90-minute group sessions and four individual telephone sessions. Primary outcome measure was the children' s body composition (BMI z-scores, waist circumference and skinfolds). The research assistant who performed the measurements was blinded for group assignment. Secondary outcome measures were the children's dietary behavior and physical activity level, parenting practices, parental feeding style, parenting style, and parental self-efficacy. Outcome measures were assessed at baseline and 4 months (shortterm) and 12 months (long-term) after baseline. Multilevel multiple regression analyses were conducted to determine the effect of the intervention on primary and secondary outcome measures. Results No intervention effects were found on children's body composition. Analyses of secondary outcomes showed positive short-term intervention effects on children's soft-drink consumption and parental responsibility regarding physical activity, encouragement to eat, psychological control, and efficacy and satisfaction with parenting. Longer-term intervention effects were found on parent 's report of children's time spent on sedentary behavior and playing outside, parental monitoring food intake, and responsibility regarding nutrition. Conclusion Although the Lifestyle Triple P intervention showed positive effects on some parent reported child behaviors and parenting measures, no effects were visible on children's body composition or objectively measured physical activity. Several adjustments of the intervention content are recommended, for example including a booster session.
    Full-text · Article · Apr 2015 · PLoS ONE
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    ABSTRACT: This study was conducted to (1) identify improvements in care quality and well-being of patients with chronic obstructive pulmonary disease in the Netherlands and (2) investigate the longitudinal relationship between these factors. This longitudinal study was conducted among patients diagnosed with chronic obstructive pulmonary disease enrolled in the Kennemer Lucht care programme in the Netherlands. Biomarker data (lung capacity) were collected at patients' health care practices in 2012. Complete case analysis was conducted, and the multiple imputation technique allowed us to report pooled results from imputed datasets. Surveys were filled out by 548/1303 (42%) patients at T0 (2012) and 569/996 (57%) remaining participants at T1. Quality of care improved significantly (p < 0.05). Analyses adjusted for well-being at T0, age, educational level, marital status, gender, lung function and health behaviours showed that patients' assessments of the quality of chronic care delivery at T0 (p < 0.01) and changes therein (p < 0.001) predicted patients' well-being at T1. These results clearly show that the quality of care and changes therein are important for the well-being of patients with chronic obstructive pulmonary disease in the primary care setting. To improve quality of care for chronically ill patients, multicomponent interventions may be needed.
    Full-text · Article · Apr 2015 · International journal of integrated care
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    ABSTRACT: Twenty-five scientists met at Aschauhof, Altenhof, Germany, to discuss various aspects of the complex network of modern health screening, focusing on current scientific topics including medical sciences, human biology, and mathematics; on problems in implementing these results at the practical level of physicians, nurses, technicians, and engineers; and the level of administrative and political decisions. Whereas major scientific advancements have been published in the understanding and the bio-statistical evaluation of anthropometric screening parameters such as serial measurements of height and weight for preventive medical check-ups, BMI screening and surveillance in schools, etc., the implementation of these advancements into current health screening concepts, strategies and decision-making is poor. Fear of discrimination, misperception of body image, behavioural responses and political concerns, meanwhile dominate and negatively interfere with the implementation of recent scientific results into public health screening concepts and practices.
    Full-text · Article · Mar 2015 · Pediatric endocrinology reviews: PER
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    Full-text · Dataset · Feb 2015
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    Full-text · Dataset · Feb 2015
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    Full-text · Dataset · Feb 2015
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    ABSTRACT: Accurate calculations of testicular volume standard deviation (SD) scores are not currently available. We constructed LMS-smoothed age-reference charts for testicular volume in healthy boys. The LMS method was used to calculate reference data, based on testicular volumes from ultrasonography and Prader orchidometer of 769 healthy Dutch boys aged six months to 19 years. We also explored the association between testicular growth and pubic hair development and data were compared to orchidometric testicular volumes from the 1997 Dutch nationwide growth study. The LMS-smoothed reference charts showed that no revision of the definition of normal onset of male puberty - from nine to 14-years-of-age - was warranted. In healthy boys, the pubic hair stage SD scores corresponded with testicular volume SD scores (r=0.394). However, testes were relatively small for pubic hair stage in Klinefelter syndrome and relatively large in immunoglobulin superfamily member 1 deficiency syndrome. The age-corrected SD scores for testicular volume will aid in the diagnosis and follow up of abnormalities in the timing and progression of male puberty and in research evaluations. The SD scores can be compared with pubic hair SD scores to identify discrepancies between cell functions that result in relative microorchidism or macroorchidism. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    No preview · Article · Feb 2015 · Acta paediatrica (Oslo, Norway: 1992). Supplement
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    ABSTRACT: Individual participant data meta-analyses (IPD-MA) are increasingly used for developing and validating multivariable (diagnostic or prognostic) risk prediction models. Unfortunately, some predictors or even outcomes may not have been measured in each study and are thus systematically missing in some individual studies of the IPD-MA. As a consequence, it is no longer possible to evaluate between-study heterogeneity and to estimate study-specific predictor effects, or to include all individual studies, which severely hampers the development and validation of prediction models. Here, we describe a novel approach for imputing systematically missing data and adopt a generalized linear mixed model to allow for between-study heterogeneity. This approach can be viewed as an extension of Resche-Rigon's method (Stat Med 2013), relaxing their assumptions regarding variance components and allowing imputation of linear and nonlinear predictors. We illustrate our approach using a case study with IPD-MA of 13 studies to develop and validate a diagnostic prediction model for the presence of deep venous thrombosis. We compare the results after applying four methods for dealing with systematically missing predictors in one or more individual studies: complete case analysis where studies with systematically missing predictors are removed, traditional multiple imputation ignoring heterogeneity across studies, stratified multiple imputation accounting for heterogeneity in predictor prevalence, and multilevel multiple imputation (MLMI) fully accounting for between-study heterogeneity. We conclude that MLMI may substantially improve the estimation of between-study heterogeneity parameters and allow for imputation of systematically missing predictors in IPD-MA aimed at the development and validation of prediction models. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    No preview · Article · Feb 2015 · Statistics in Medicine
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    ABSTRACT: To derive regional weight-for-age growth references to help optimize age-based dosing of antimalarials in Africa, the Americas, South-East Asia and the Western Pacific. A weight-for-age database was constructed from pre-existing population-based anthropometric data obtained from household surveys and research groups. It contained data collected between 1995 and 2012 on 1 263 119 individuals (909 368 female, 353 751 male) older than 14 days and younger than 50 years in 64 malaria-endemic countries. Regional growth references were generated using a generalized additive model for location, scale and shape by combining data with varying distributions from a range of sources. Countries were weighted by their population at risk of malaria to enable references to be used in optimizing the dosing of antimalarials. Large differences in weight-for-age distributions existed between the regions and between the regions and global growth standards. For example, the average adult male from the Americas weighed 68.1 kg - 6.0 kg more than males in South-East Asia and the Western Pacific (average: 62.1 kg). For adult women, the difference was over 10.4 kg: the average was 60.4 kg in the Americas and 50.0 kg in South-East Asia and the Western Pacific. There were substantial variations in weight-for-age growth curves between malaria-endemic areas. The growth reference charts derived here can be used to guide the evidence-based optimization of aged-based dosing regimens for antimalarials and other drugs often prescribed by age.
    Full-text · Article · Feb 2015 · Bulletin of the World Health Organisation
  • Stef van Buuren
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    ABSTRACT: Longitudinal growth data are valuable for predicting and interpreting future growth of individual children. This note explores the idea of 'curve matching', a new technique to improve prediction of future growth of an individual child. The key idea is to find existing children in existing databases that are similar to the current child. The growth patterns of the matched children suggest how the current child might evolve in the future. This paper describes the various conceptual and practical issues that need to be addressed before the idea can take off. A demo implementation is available at http://vps.stefvanbuuren.nl:3838/frisodemo/. © 2014 S. Karger AG, Basel.
    No preview · Article · Nov 2014 · Annals of Nutrition and Metabolism
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    Gerko Vink · Stef van Buuren
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    ABSTRACT: Current pooling rules for multiply imputed data assume infinite populations. In some situations this assumption is not feasible as every unit in the population has been observed, potentially leading to over-covered population estimates. We simplify the existing pooling rules for situations where the sampling variance is not of interest. We compare these rules to the conventional pooling rules and demonstrate their use in a situation where there is no sampling variance. Using the standard pooling rules in situations where sampling variance should not be considered, leads to overestimation of the variance of the estimates of interest, especially when the amount of missingness is not very large. As a result, populations estimates are over-covered, which may lead to a loss of statistical power. We conclude that the theory of multiple imputation can be extended to the situation where the sample happens to be the population. The simplified pooling rules can be easily implemented to obtain valid inference in cases where we have observed essentially all units and in simulation studies addressing the missingness mechanism only.
    Full-text · Article · Sep 2014
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    ABSTRACT: Background: Although children both at the upper and lower tail of the body mass index (BMI) distribution are at greater health risk, relatively little is known about the development of thinness prevalence rates in developed countries over time. We studied trends in childhood thinness and assessed changes in the BMI distribution since the onset of the obesity epidemic. Methods: Growth data from 54 814 children aged 2-18 years of Dutch, Turkish and Moroccan origin living in The Netherlands were used. Anthropometric measurements were performed during nationwide cross-sectional growth studies in 1980 (only Dutch), 1997 and 2009. Prevalence rates of thinness grades I, II and III were calculated according to international cut-offs. BMI distributions for 1980, 1997 and 2009 were compared. Results: Since 1980, thinness (all grades combined) reduced significantly from 14.0% to 9.8% in children of Dutch origin, but the proportion of extremely thin children (grade III) remained constant. Thinness in children of Moroccan origin decreased significantly from 8.8% to 6.2% between 1997 and 2009. No significant difference was observed in children of Turkish origin (5.4% in 1997 vs. 5.7% in 2009). Thinness occurred most often in children aged 2-5 years. There were no differences between boys and girls. The BMI distribution widened since 1980, mainly due to an upward shift of the upper centiles. Conclusion: Since the onset of the obesity epidemic, prevalence rates of thinness decreased. However, we found a small but persistent group of extremely thin children. More research is needed to gain insight into their health status.
    Full-text · Article · Aug 2014 · The European Journal of Public Health

Publication Stats

7k Citations
369.64 Total Impact Points

Institutions

  • 2012-2015
    • Nederlandse Organisatie voor Wetenschappelijk Onderzoek
      's-Gravenhage, South Holland, Netherlands
    • University of Applied Sciences Leiden
      Leyden, South Holland, Netherlands
  • 2006-2015
    • Utrecht University
      • Department of Methodology and Statistics
      Utrecht, Utrecht, Netherlands
    • Harvard University
      Cambridge, Massachusetts, United States
    • VU University Amsterdam
      Amsterdamo, North Holland, Netherlands
  • 2010-2013
    • TNO
      Delft, South Holland, Netherlands
  • 2005-2009
    • Centraal Bureau voor de Statistiek
      's-Gravenhage, South Holland, Netherlands
    • Liverpool School of Tropical Medicine
      • Child and Reproductive Health Group
      Liverpool, England, United Kingdom
  • 2000-2005
    • Leiden University Medical Centre
      • Department of Pediatrics
      Leyden, South Holland, Netherlands