Gerard van Breukelen

Gerard van Breukelen
Maastricht University | UM · Dept. of Methodology and Statistics

PhD

About

225
Publications
98,189
Reads
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10,801
Citations
Additional affiliations
July 1991 - December 2021
Maastricht University
Position
  • Professor (Full)
January 1990 - April 1991
Medical Research Bureau Int.
Position
  • head
Description
  • design and analysis of randomized trials on antimicrobial agents and cardiovascular drugs
August 1984 - June 1990
Radboud University
Position
  • Professor (Assistant)
Description
  • PhD student 1984-1988 Assistant Professor 1988-1990
Education
August 1979 - May 1989
Radboud University
Field of study
  • mathematical psychology and psychometrics

Publications

Publications (225)
Article
Objectives: Tinnitus is the perception of sound without an external source, affecting quality of life that can cause severe distress in approximately 1 to 3% of the population of people with tinnitus. Randomized controlled trials of cognitive behavioral therapy for tinnitus have demonstrated its effectiveness in improving quality of life, but the...
Article
The literature on dealing with missing covariates in nonrandomized studies advocates the use of sophisticated methods like multiple imputation (MI) and maximum likelihood (ML)-based approaches over simple methods. However, these methods are not necessarily optimal in terms of bias and efficiency of treatment effect estimation in randomized studies,...
Article
The use of longitudinal finite mixture models (FMMs) to identify latent classes of individuals following similar paths of temporal development is gaining traction in applied research. However, FMM’s users may be unaware of how data features as well as the inappropriate specification of the model’s covariance structure impacts class enumeration. To...
Article
To prevent mistakes in psychological assessment, the precision of test norms is important. This can be achieved by drawing a large normative sample and using regression-based norming. Based on that norming method, a procedure for sample size planning to make inference on Z-scores and percentile rank scores is proposed. Sampling variance formulas fo...
Article
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Cluster randomized trials evaluate the effect of a treatment on persons nested within clusters, with clusters being randomly assigned to treatment. The optimal sample size at the cluster and person level depends on the study cost per cluster and per person, and the outcome variance at the cluster and the person level. The variances are unknown in t...
Article
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The bivariate normal multilevel model (MLM) provides a flexible modeling framework for cost-effectiveness analyses (CEAs) alongside cluster randomized trials (CRTs) as well as for sample size calculations of these trials. The bivariate MLM assumes a joint normal distribution for effects and costs, both within (individual level) and between (cluster...
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We present a novel method, REMAXINT, that captures the gist of two-way interaction in row by column (i.e., two-mode) data, with one observation per cell. REMAXINT is a probabilistic two-mode clustering model that yields two-mode partitions with maximal interaction between row and column clusters. For estimation of the parameters of REMAXINT, we max...
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Worldwide, adherence to national guidelines for physical activity (PA), and fruit and vegetable consumption is recommended to promote health and reduce the risk for (chronic) disease. This study reports on the effectiveness of various social-cognitive interventions to improve adherence to guidelines and the revealed adherence predictors. Participan...
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Background: Community care professionals need to encourage older adults in performing functional activities to maintain independence. However, professionals often perform functional activities on behalf of older adults. To change this, insights into the behavior and barriers of professionals in encouraging activities are required. In the current s...
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To estimate the mean of a quantitative variable in a hierarchical population, it is logistically convenient to sample in two stages (two-stage sampling), i.e. selecting first clusters, and then individuals from the sampled clusters. Allowing cluster size to vary in the population and to be related to the mean of the outcome variable of interest (in...
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In this article, we first review the literature on dealing with missing values on a covariate in randomized studies and summarize what has been done and what is lacking to date. We then investigate the situation with a continuous outcome and a missing binary covariate in more details through simulations, comparing the performance of multiple imputa...
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The use of finite mixture modelling (FMM) is becoming increasingly popular for the analysis of longitudinal repeated measures data. FMMs assist in identifying latent classes following similar paths of temporal development. This paper aims to address the confusion experienced by practitioners new to these methods by introducing the various available...
Article
Objective To assess the efficacy of a 12-week aquatic cycling training program for improving knee pain and physical functioning in patients with knee osteoarthritis. Design Two-arm, single-blind, parallel-group randomized controlled trial. Settings OA outpatient clinic of the Maastricht University Medical Center. Participants Patients (N=111, 50...
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This longitudinal study explored the relations between fear-enhancing parenting behaviors (modeling and threat information transmission) and children’s cognitive biases and anxiety symptoms on three subsequent time points over a one-year period. Participants were 216 children aged 7–12 years (114 boys and 102 girls), and their mothers (n = 199) and...
Article
Background and objectives: Affective hyperreactivity is a core feature of Borderline Personality Disorder (BPD), yet little is known about reactivity of positive affect (PA). Objectives were to explore the relationship between BPD traits and affect reactivity in response to a personalized PA-induction and a subsequent stressor. Patient status (see...
Article
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In multilevel populations, there are two types of population means of an outcome variable ie, the average of all individual outcomes ignoring cluster membership and the average of cluster‐specific means. To estimate the first mean, individuals can be sampled directly with simple random sampling or with two‐stage sampling (TSS), that is, sampling cl...
Chapter
The usual treatment allocation in randomized trials and their factorial and nested extensions is balanced, that is, with equal sample size in each treatment arm. This is optimal only when the variances and study costs are the same in both treatment arms or when the ratio of treatment‐specific variances is equal to the ratio of treatment‐specific co...
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The cost-effectiveness of interventions (e.g. new medical therapies or health care technologies) is often evaluated in randomized clinical trials, where individuals are nested within clusters, for instance patients within general practices. In such two-level cost-effectiveness trials, one can randomly assign treatments to individuals within cluster...
Article
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Background According to the principles of Reablement, home care services are meant to be goal-oriented, holistic and person-centred taking into account the capabilities and opportunities of older adults. However, home care services traditionally focus on doing things for older adults rather than with them. To implement Reablement in practice, the ‘...
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Background: Metabolic health in people with obesity is determined by body composition. In this study, we examined the influence of a combined strength exercise and motivational programme -embedded in the school curriculum- on adolescents body composition and daily physical activity. Methods: A total of 695 adolescents (11-15y) from nine Dutch se...
Data
Data S1. Supporting information
Article
In sub-Saharan Africa, theory and evidenced-based interventions that are systematically designed and using sound evaluation methods to report on effectiveness are limited. A sex education programme called SPEEK was developed, implemented and evaluated in Ghana using the Intervention Mapping approach. SPEEK aimed at delaying sexual initiation, reduc...
Article
Full-text available
Cluster randomized trials evaluate the effect of a treatment on persons nested within clusters, where treatment is randomly assigned to clusters. Current equations for the optimal sample size at the cluster and person level assume that the outcome variances and/or the study costs are known and homogeneous between treatment arms. This paper presents...
Article
Full-text available
We tested the effectiveness of a program consisting of motivational interviewing (MI) and feedback of urine cotinine to stop passive smoking (PS) in children at risk for asthma. Fifty-eight families with children 0–13 years with a high risk of asthma and PS exposure were randomised in a one-year follow-up study. The intervention group received the...
Article
Objective: Cognitive behavioural treatments (CBT) for the reduction of tinnitus complaints have been shown to be effective; however the specific mechanisms of change are yet to be unveiled. Reductions in tinnitus-related fear have been indicated to be an important factor in alleviating tinnitus suffering. The role of tinnitus-related fear has been...
Article
At the design stage of a study, it is crucial to compute the sample size needed for treatment effect estimation with maximum precision and power. The optimal design depends on the costs, which may be known at the design stage, and on the outcome variances, which are unknown. A balanced design, optimal for homogeneous costs and variances, is typical...
Article
Objective: To examine the time course and predictors of fear of cancer recurrence (FCR) in breast cancer survivors over a period of 18 months after initial surgery. Methods: Breast cancer patients (n = 267) were followed until 18 months after primary breast surgery. Shortly after surgery, participants completed the Life Orientation Test-Revised...
Article
Working Memory (WM) plays a crucial role in successful self-regulation of behavior, including weight regulation. Improving WM might therefore be a promising strategy to support weight loss. In the present study, overweight individuals with a desire to lose weight (N = 91) received an online lifestyle intervention, in conjunction with either 25 sess...
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Planners of longitudinal studies of binary responses in applied sciences have not yet benefitted from optimal designs, which have been shown to improve precision of model parameter estimates, due to absence of a computer program. An interactive computer program for Bayesian optimal binary repeated measurements designs is presented for this purpose.
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Objectives: There is preliminary evidence for the efficacy of positive psychology interventions for pain management. The current study examined the effects of an internet-based positive psychology self-help program for patients with chronic musculoskeletal pain and compared it with an internet-based cognitive behavioural program. Methods: A rand...
Article
Background: Laparoscopic left lateral sectionectomy (LLLS) has been associated with shorter hospital stay and reduced overall morbidity compared with open left lateral sectionectomy (OLLS). Strong evidence has not, however, been provided. Methods: In this multicentre double-blind RCT, patients (aged 18-80 years with a BMI of 18-35 kg/m(2) and AS...
Article
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Hazard Banding (HB) is a process of allocating chemical substances in bands of increasing health hazard based on their hazard classifications. Recent Control Banding (CB) tools use the classifications of the United Nations Global Harmonized System (UN GHS) or the European Union Classifications, Labelling and Packaging (EU CLP) which are grouped ove...
Conference Paper
Abstract Background We developed the Assessment of Burden of COPD (ABC) tool consisting of a short validated questionnaire assessing the experienced burden of COPD (Slok et al, COPD: Journal of COPD 2016; epub ahead of print), objective COPD severity indicators (e.g., lung function), and a treatment algorithm visualising outcomes (Figure 1) and pr...
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Objective Assessing the effectiveness of the Assessment of Burden of COPD (ABC) tool on disease-specific quality of life in patients with chronic obstructive pulmonary disease (COPD) measured with the St. George's Respiratory Questionnaire (SGRQ), compared with usual care. Methods A pragmatic cluster randomised controlled trial, in 39 Dutch primar...
Article
Sexual harassment—unwanted sexual comments, advances, or behaviors—and sexual violence are still prevalent worldwide, leading to a variety of physical, cognitive, and emotional problems among those being harassed. In particular, youth in care are at risk of becoming perpetrators (and victims) of sexual harassment. However, in general, there are ver...
Article
Typically, clusters and individuals in cluster randomized trials are allocated across treatment conditions in a balanced fashion. This is optimal under homogeneous costs and outcome variances. However, both the costs and the variances may be heterogeneous. Then, an unbalanced allocation is more efficient but impractical as the outcome variance is u...
Article
Objectives: A proposed method for bridging the gap between clinically relevant epilepsy outcome measures and quality-adjusted life years is to derive utility scores for epilepsy health states. The aim of this study is to develop such a utility-function and to investigate the impact of the epilepsy outcome measures on utility. Methods: Health sta...
Article
In two-armed trials with clustered observations the arms may differ in terms of (i) the intraclass correlation, (ii) the outcome variance, (iii) the average cluster size, and (iv) the number of clusters. For a linear mixed model analysis of the treatment effect, this paper examines the expected efficiency loss due to varying cluster sizes based upo...
Article
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Objectives: The aim of this study is to investigate the association between age, gender, body-mass index, smoking behavior, orthopedic comorbidity, neurologic comorbidity, cardiac comorbidity, vascular comorbidity, pulmonic comorbidity, internal comorbidity and Initial Claudication Distance during and after Supervised Exercise Therapy at 1, 3, 6 a...
Data
Plots of predicted values for the total sample per subgroup of age, BMI and vascular comorbidity to visualise interactions with time. Plot of predicted values for the total sample per subgroup of age (Fig A). Plot of predicted values for the total sample per subgroup of BMI (Fig B). Plot of predicted values for the total sample per subgroup of vasc...
Article
Objective: Assessment of the effectiveness of the Assessment of Burden of COPD (ABC) tool on disease-specific quality of life in patients with Chronic Obstructive Pulmonary Disease (COPD). Design: Cluster-randomised controlled trial. Method: This concerned a trial in 39 Dutch primary care practices and 17 hospitals, involving 357 patients with...
Article
Little is known about how contextual factors influence psychosocial determinants of travel mode choice. The reported study examined the effect of organizational sector and geographical region on an Extended Theory of Planned Behavior (TPB) model of commuting travel mode choice. Multigroup structural equation model analyses were conducted to test fo...
Article
Background: Goals and objectives as mentioned in Individual Support Plans (ISPs) were analysed to explore what domains of quality of life they are associated with, what support resources are referenced for achieving the goals, and how domains and resources are related to clients age, gender and intellectual disability (ID) level. Method: A total...
Article
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This study tested Expand Your Horizon, a programme designed to improve body image by training women to focus on the functionality of their body using structured writing assignments. Eighty-one women (Mage=22.77) with a negative body image were randomised to the Expand Your Horizon programme or to an active control programme. Appearance satisfaction...
Article
Sample size calculation for cluster randomized trials (CRTs) with a 2 Â 2 factorial design is complicated due to the combination of nesting (of individuals within clusters) with crossing (of two treatments). Typically, clusters and individuals are allocated across treatment conditions in a balanced fashion, which is optimal under homogeneity of var...
Article
Theory of Mind (ToM) is a social perceptual skill that refers to the ability to take someone else's perspective and infer what others think. The current study examined the effect of potential hostility biases, as well as controlled (slow) versus automatic (fast) processing on ToM performance in psychopathy. ToM abilities (as assessed with the Readi...
Article
When comparing two different kinds of group therapy or two individual treatments where patients within each arm are nested within care providers, clustering of observations may occur in both arms. The arms may differ in terms of (a) the intraclass correlation, (b) the outcome variance, (c) the cluster size, and (d) the number of clusters, and there...
Article
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Background: Borderline personality disorder (BPD) is a severe and highly prevalent mental disorder. Schema therapy (ST) has been found effective in the treatment of BPD and is commonly delivered through an individual format. A group format (group schema therapy, GST) has also been developed. GST has been found to speed up and amplify the treatment...
Article
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Background Chronic Obstructive Pulmonary Disease (COPD) is a growing worldwide problem that imposes a great burden on the daily life of patients. Since there is no cure, the goal of treating COPD is to maintain or improve quality of life. We have developed a new tool, the Assessment of Burden of COPD (ABC) tool, to assess and visualize the integrat...
Article
In medicine and health sciences mixed effects models are often used to study time-structured data. Optimal designs for such studies have been shown useful to improve the precision of the estimators of the parameters. However, optimal designs for such studies are often derived under the assumption of a zero autocorrelation between the errors, especi...
Chapter
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The increasing cost of drug development has raised the demand on the use of biomarkers as surrogate endpoints for the evaluation of new drugs in clinical trials. However, failed past attempts to use surrogate endpoints made it clear that, before deciding on the use of a candidate surrogate endpoint, it is of the utmost importance to investigate its...
Article
Bayesian optimal designs for binary longitudinal responses analyzed with mixed logistic regression describing a linear time effect are considered. In order to find the optimal number and allocations of time points, for different priors, cost constraints and covariance structures of the random effects, a scalar function of the approximate informatio...
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Substantial energy savings can be achieved by reducing energy use in office buildings. The reported study used a Theory of Planned Behavior (TPB) model extended with perceived habit to explain office energysaving behaviors. One aim was to examine if organizational contextual variability independently predicted office energy-saving behaviors over an...
Article
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From a corporate social responsibility perspective, there are many reasons to promote teleconference use as an alternative to business travel. The present study examines psychosocial and organizational factors relevant to teleconference use. We tested an extended Theory of Planned Behavior model of teleconference use among office workers of four or...
Article
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For functional magnetic resonance imaging (fMRI) studies, researchers can use multisubject blocked designs to identify active brain regions for a certain stimulus type of interest. Before performing such an experiment, careful planning is necessary to obtain effi�cient stimulus eff�ect estimators within the available fi�nancial resources. The op...