Stef van Buuren's research while affiliated with Utrecht University and other places

Publications (220)

Article
Full-text available
Background Multiple imputation is frequently used to address missing data when conducting statistical analyses. There is a paucity of research into the performance of multiple imputation when the prevalence of missing data is very high. Our objective was to assess the performance of multiple imputation when estimating a logistic regression model wh...
Preprint
Curve matching is a prediction technique that relies on predictive mean matching, which matches donors that are most similar to a target based on the predictive distance. Even though this approach leads to high prediction accuracy, the predictive distance may make matches look unconvincing, as the profiles of the matched donors can substantially di...
Chapter
Predictive mean matching (PMM) is an easy-to-use and versatile univariate imputation approach. It is robust against transformations of the incomplete variable and violation of the normal model. However, univariate imputation methods cannot directly preserve multivariate relations in the imputed data. We wish to extend PMM to a multivariate method t...
Preprint
Background: Combining existing data sets for meta-analyses enables analyses across multiple contexts and conditions. However, the use of different measurement instruments in different studies hampers comparability. This paper proposes a novel method to link tools administered across multiple studies. Methods: The proposed methodology starts by form...
Article
Full-text available
Background Loss to follow-up is a major challenge for very preterm (VPT) cohorts; attrition is associated with social disadvantage and parents with impaired children may participate less in research. We investigated the impact of loss to follow-up on the estimated prevalence of neurodevelopmental impairment in a VPT cohort using different methodolo...
Preprint
Full-text available
Iterative imputation is a popular tool to accommodate missing data. While it is widely accepted that valid inferences can be obtained with this technique, these inferences all rely on algorithmic convergence. There is no consensus on how to evaluate the convergence properties of the method. Our study provides insight into identifying non-convergenc...
Article
Full-text available
Aim We investigated timing of survival differences and effects on morbidity for fetuses alive at maternal admission to hospital delivered at 22 to 26 weeks' gestational age (GA). Methods Data for from the EXPRESS (Sweden, 2004-07), EPICure-2 (England, 2006), and EPIPAGE- 2 (France, 2011) cohorts were harmonised. Survival, stratified by GA, was ana...
Article
Full-text available
The purpose of this study was to develop and test personalized predictions for functional recovery after Total Knee Arthroplasty (TKA) surgery, using a novel neighbors-based prediction approach. We used data from 397 patients with TKA to develop the prediction methodology and then tested the predictions in a temporally distinct sample of 202 patien...
Preprint
Full-text available
This study evaluates changes in neonatal morbidity and care practices of very preterm (VP) infants born in the Netherlands in the 1980s and 2000s and analyzes whether these changes were associated with infant and maternal characteristics, risk factors during pregnancy, and obstetrical outcomes. The community-based cohorts of POPS (1983) and LOLLIPO...
Article
Full-text available
The chapter familiarises the reader with an intuitive yet powerful methodology to tune instruments to a common unit, presenting a fresh approach that expresses measurements made by different instruments on the D-score scale. As a result, the reader may compare D-scores between ages, children or cohorts. It shows how to exploit common developmental...
Article
Full-text available
The chapter equips the reader with a basic understanding of robust psychometric methods that are needed to turn developmental milestones into measurements, introducing the fundamental issues in defining a unit for child development and demonstrates the relevant quantitative methodology. It reviews quantitative approaches to measuring child developm...
Article
Full-text available
Multiple imputation is a recommended technique to deal with missing data. We study the problem where the investigator has already created imputations before the arrival of the next wave of data. The newly arriving data contain missing values that need to be imputed. The standard method (RE-IMPUTE) is to combine the new and old data before imputatio...
Article
Full-text available
Physiologic data from anesthesia monitors are automatically captured. Yet erroneous data are stored in the process as well. While this is not interfering with clinical care, research can be affected. Researchers should find ways to remove artifacts. The aim of the present study was to compare different artifact annotation strategies, and to assess...
Article
Full-text available
Missing data is a common occurrence in clinical research. Missing data occurs when the value of the variables of interest are not measured or recorded for all subjects in the sample. Common approaches to addressing the presence of missing data include complete-case analyses, in which subjects with missing data are excluded, or mean-value imputation...
Article
Full-text available
Background: Clinicians and patients lack an evidence-based framework by which to judge individual-level recovery following total knee arthroplasty (TKA) surgery, thus impeding personalized treatment approaches for this elective surgery. Our study aimed to develop and validate a reference chart for monitoring recovery of knee flexion following TKA...
Article
What we already know about this topic: Electronically collected data are increasingly used for clinical research, but include artifacts and other errorsHow best to filter electronically recorded intraoperative blood pressure remains unknown WHAT THIS ARTICLE TELLS US THAT IS NEW: The authors identified 38 papers describing blood pressure artifact-...
Article
Full-text available
Background: Intraoperative blood pressure has been suggested as a key factor for safe pediatric anesthesia. However, there is not much insight into factors that discriminate between children with low and normal pre-incision blood pressure. Our aim was to explore if children who have a low blood pressure during anesthesia are different than those w...
Article
Full-text available
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-sco...
Preprint
Multiple imputation is a highly recommended technique to deal with missing data, but the application to longitudinal datasets can be done in multiple ways. When a new wave of longitudinal data arrives, we can treat the combined data of multiple waves as a new missing data problem and overwrite existing imputations with new values (re-imputation). A...
Article
Full-text available
Background Gestational weight gain differs according to pre-pregnancy body mass index and is related to the risks of adverse maternal and child health outcomes. Gestational weight gain charts for women in different pre-pregnancy body mass index groups enable identification of women and offspring at risk for adverse health outcomes. We aimed to cons...
Article
We investigated how different graphical representations convey the underlying uncertainty distribution in ensemble predictions. In ensemble predictions, a set of forecasts is produced, indicating the range of possible future states. Adopting a use case from life sciences, we asked non-expert participants to compare ensemble predictions of the growt...
Article
Full-text available
In healthcare cost‐effectiveness analysis, probability distributions are typically skewed and missing data are frequent. Bootstrap and multiple imputation are well‐established resampling methods for handling skewed and missing data. However, it is not clear how these techniques should be combined. This paper addresses combining multiple imputation...
Article
We systematically reviewed papers published in English between 1994 and October 2015 on how postnatal weight gain and growth affect neurodevelopment and metabolic outcomes in term-born small-for-gestational-age (SGA) infants. Two randomised trials reported that enriched infant formulas that promoted early growth also increased fat mass, lean mass a...
Article
Full-text available
We systematically reviewed papers published in English between 1994 and October 2015 on how postnatal weight gain and growth affect neurodevelopment and metabolic outcomes in term-born small-for-gestational-age (SGA) infants. Two randomised trials reported that enriched infant formulas that promoted early growth also increased fat mass, lean mass a...
Article
Full-text available
Background/aims: Childhood stunting is a prevalent problem in low- and middle-income countries and is associated with long-term adverse neurodevelopment and health outcomes. In this review, we define indicators of growth, discuss key challenges in their analysis and application, and offer suggestions for indicator selection in clinical research co...
Article
Full-text available
We present and compare multiple imputation methods for multilevel continuous and binary data where variables are systematically and sporadically missing. We particularly focus on three recent approaches: the joint modelling approach of Quartagno and Carpenter (2016a) and the fully conditional specification approaches of Jolani et al. (2015) and Res...
Article
Full-text available
Gifi was the nom de plume for a group of researchers led by Jan de Leeuw at the University of Leiden. Between 1970 and 1990 the group produced a stream of theoretical papers and computer programs in the area of nonlinear multivariate analysis that were very innovative. In an informal way this paper discusses the so-called Gifi system of nonlinear m...
Article
Full-text available
Background: Although noninvasive blood pressure (NIBP) monitoring during anesthesia is a standard of care, reference ranges for blood pressure in anesthetized children are not available. We developed sex- and age-specific reference ranges for NIBP in children during anesthesia and surgery. Methods: In this retrospective observational cohort stud...
Article
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...
Article
Full-text available
Large scale assessment data often has a multilevel structure. When dealing with missing values, such structures need to be taken into account to prevent underestimation of the intraclass correlation. We evaluate predictive mean matching (PMM) as a multilevel imputation technique and compare it to other imputation approaches for multilevel data. We...
Article
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 ou...
Article
Full-text available
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 grow...
Article
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...
Article
Full-text available
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 yea...
Article
Full-text available
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 Studi...
Article
Full-text available
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 t...
Article
Full-text available
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...
Article
Full-text available
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...
Article
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 consequenc...
Article
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 si...
Article
Full-text available
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 bet...
Article
Full-text available
The sensitivity of multiple imputation methods to deviations from their distributional assumptions is investigated using simulations, where the parameters of scientific interest are the coefficients of a linear regression model, and values in predictor variables are missing at random. The performance of a newly proposed imputation method based on g...
Article
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...
Article
Full-text available
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...
Article
Full-text available
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...
Conference Paper
We propose a new multiple imputation technique for imputing squares. Cur- rent methods yield either unbiased regression estimates, or preserve data re- lations. No method, however, seems to deliver both, which limits researchers in the implementation of regression analysis in the presence of missing data. Besides, current methods only work...
Article
Full-text available
Background: People from Asian populations are generally shorter than other ethnic groups. It is unknown if current universal height references are suitable for affluent South Asian children in the Netherlands. Aims: To develop height-for-age charts for contemporary South Asian children aged 0-20 years living in the Netherlands, to evaluate secul...
Article
Full-text available
Objectives Recently, the Individual Work Performance Questionnaire (IWPQ) version 0.2 was developed. One of its main purposes is to detect changes in individual work performance, for example in worksite health promotion interventions. The IWPQ is a generic instrument, i.e. suitable for blue, pink, and white collar workers, that was constructed usin...
Article
Full-text available
Objective: To develop a short instrument to measure determinants of innovations that may affect its implementation. Design: We pooled the original data from eight empirical studies of the implementation of evidence-based innovations. The studies used a list of 60 potentially relevant determinants based on a systematic review of empirical studies...
Article
Full-text available
Morbid obesity can be a life threatening condition. The aim of our study is to assess the trend in morbid obesity in The Netherlands among children of Dutch origin since 1980, and among children of Turkish and Moroccan origin since 1997. Cross-sectional height and weight data of children of Dutch, Turkish and Moroccan origin aged 2-18 years were se...
Article
Standard approaches to implement multiple imputation do not automatically incorporate nonlinear relations like interaction effects. This leads to biased parameter estimates when interactions are present in a dataset. With the aim of providing an imputation method which preserves interactions in the data automatically, the use of recursive partition...
Article
Full-text available
There are very few norms to evaluate and monitor the health and functioning of the elderly. This paper proposes a compact spatial representation of 25 health measurements of European citizens older than 50 years. Data from 44,285 unique individuals were obtained from the EU-wide Survey of Health, Ageing and Retirement in Europe(SHARE) data collecte...
Article
Full-text available
The association between poverty, malnutrition, illness and poor socioeconomic conditions on the one side, and poor growth and short adult stature on the other side, is well recognized. Yet, the simple assumption by implication that poor growth and short stature result from poor living conditions, should be questioned. Recent evidence on the impact...
Article
Multiple imputation methods properly account for the uncertainty of missing data. One of those methods for creating multiple imputations is predictive mean matching (PMM), a general purpose method. Little is known about the performance of PMM in imputing non-normal semicontinuous data (skewed data with a point mass at a certain value and otherwise...
Article
InleidingGroei is een afspiegeling van de gezondheid van een populatie. Als we naar de Nederlandse geschiedenis kijken, zijn er al sinds het jaar 50 van onze jaartelling gegevens over lengte beschikbaar. Deze gegevens zijn veelal afgeleid uit metingen van pijpbeenderen of skeletten en gebaseerd op kleine aantallen en verschillende bevolkingsgroepen...
Article
Full-text available
It is known that height and body mass index (BMI) are correlated in childhood. However, its impact on the (trend of) national prevalence rates of overweight and obesity has never been investigated. The aim of our study is to investigate the relation between height and national prevalence rates of overweight and obesity in childhood between 1980, 19...
Article
Full-text available
Objective: Many health-promoting interventions combine multiple behavior change techniques (BCTs) to maximize effectiveness. Although, in theory, BCTs can amplify each other, the available meta-analyses have not been able to identify specific combinations of techniques that provide synergistic effects. This study overcomes some of the shortcomings...