Young children's performance on a design fluency task: longitudinal data on total number of designs, clustering and switching, and regression-based norms.

INTRODUCTION: Design fluency (DF) tasks are commonly used to assess executive functions such as attentional control, cognitive flexibility, self-monitoring and strategy use. Next to the total number of correct designs, the standard outcome of a DF task, clustering and switching can help disentangle the processes underlying DF performance. We present the first longitudinal study of 4-8-year-old children's developmental DF trajectories. METHOD: At initial enrollment, children (n = 228) were aged between 4.05 and 6.88 years (M = 5.18, SD = 0.59) and attended Dutch primary schools. The DF task was administered at three time points, each time point separated by approximately 1 year. Data were analyzed using mixed regression for total number of correct designs and switching, and mixed logistic regression analysis for clustering. RESULTS: The total number of correct designs increased linearly across the three time points. Across all time points, children made very few clusters, and most clusters consisted of only 3 designs. Clustering only increased at the third assessment compared to the two previous assessments. Switching increased up to the second assessment, but not after that. The number of switches was highly correlated with the total number of correct designs at all time points (r = 0.78 to r = 0.85). These developmental trajectories were similar for all children regardless of their baseline age. Normative data are given for the total number of correct designs and switching. CONCLUSIONS: Children as of age 4 onwards can perform a DF task. For children as young as 4-8 years old, computing clustering, and switching measures is of limited value to study cognitive processes underlying DF performance, next to the total number of correct designs. There were no sex differences on any of the DF outcomes. Level of parental education (LPE) was positively associated with the total number of correct designs and switching.

Laparoscopic Versus Open Hemihepatectomy: The ORANGE II PLUS Multicenter Randomized Controlled Trial.

PURPOSE: To compare outcomes after laparoscopic versus open major liver resection (hemihepatectomy) mainly for primary or metastatic cancer. The primary outcome measure was time to functional recovery. Secondary outcomes included morbidity, quality of life (QoL), and for those with cancer, resection margin status and time to adjuvant systemic therapy. PATIENTS AND METHODS: This was a multicenter, randomized controlled, patient-blinded, superiority trial on adult patients undergoing hemihepatectomy. Patients were recruited from 16 hospitals in Europe between November 2013 and December 2018. RESULTS: Of the 352 randomly assigned patients, 332 patients (94.3%) underwent surgery (laparoscopic, n = 166 and open, n = 166) and comprised the analysis population. The median time to functional recovery was 4 days (IQR, 3-5; range, 1-30) for laparoscopic hemihepatectomy versus 5 days (IQR, 4-6; range, 1-33) for open hemihepatectomy (difference, -17.5% [96% CI, -25.6 to -8.4]; P < .001). There was no difference in major complications (laparoscopic 24/166 [14.5%] v open 28/166 [16.9%]; odds ratio [OR], 0.84; P = .58). Regarding QoL, both global health status (difference, 3.2 points; P < .001) and body image (difference, 0.9 points; P < .001) scored significantly higher in the laparoscopic group. For the 281 (84.6%) patients with cancer, R0 resection margin status was similar (laparoscopic 106 [77.9%] v open 122 patients [84.1%], OR, 0.60; P = .14) with a shorter time to adjuvant systemic therapy in the laparoscopic group (46.5 days v 62.8 days, hazard ratio, 2.20; P = .009). CONCLUSION: Among patients undergoing hemihepatectomy, the laparoscopic approach resulted in a shorter time to functional recovery compared with open surgery. In addition, it was associated with a better QoL, and in patients with cancer, a shorter time to adjuvant systemic therapy with no adverse impact on cancer outcomes observed.

Cluster Randomized Trials with a Pretest and Posttest: Equivalence of Three-, Two- and One-Level Analyses, and Sample Size Calculation.

In a cluster randomized trial clusters of persons, for instance, schools or health centers, are assigned to treatments, and all persons in the same cluster get the same treatment. Although less powerful than individual randomization, cluster randomization is a good alternative if individual randomization is impossible or leads to severe treatment contamination (carry-over). Focusing on cluster randomized trials with a pretest and post-test of a quantitative outcome, this paper shows the equivalence of four methods of analysis: a three-level mixed (multilevel) regression for repeated measures with as levels cluster, person, and time, and allowing for unstructured between-cluster and within-cluster covariance matrices; a two-level mixed regression with as levels cluster and person, using change from baseline as outcome; a two-level mixed regression with as levels cluster and time, using cluster means as data; a one-level analysis of cluster means of change from baseline. Subsequently, similar equivalences are shown between a constrained mixed model and methods using the pretest as covariate. All methods are also compared on a cluster randomized trial on mental health in children. From these equivalences follows a simple method to calculate the sample size for a cluster randomized trial with baseline measurement, which is demonstrated step-by-step.

Best (but oft forgotten) practices: Efficient sample sizes for commonly used trial designs.

Designing studies such that they have a high level of power to detect an effect or association of interest is an important tool to improve the quality and reproducibility of findings from such studies. Since resources (research subjects, time, and money) are scarce, it is important to obtain sufficient power with minimum use of such resources. For commonly used randomized trials of the treatment effect on a continuous outcome, designs are presented that minimize the number of subjects or the amount of research budget when aiming for a desired power level. This concerns the optimal allocation of subjects to treatments and, in case of nested designs such as cluster-randomized trials and multicenter trials, also the optimal number of centers versus the number of persons per center. Since such optimal designs require knowledge of parameters of the analysis model that are not known in the design stage, in particular outcome variances, maximin designs are presented. These designs guarantee a prespecified power level for plausible ranges of the unknown parameters and minimize research costs for the worst-case values of these parameters. The focus is on a 2-group parallel design, the AB/BA crossover design, and cluster-randomized and multicenter trials with a continuous outcome. How to calculate sample sizes for maximin designs is illustrated for examples from nutrition. Several computer programs that are helpful in calculating sample sizes for optimal and maximin designs are discussed as well as some results on optimal designs for other types of outcomes.

Sample size calculation and optimal design for regression-based norming of tests and questionnaires.

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 for these norm statistics are derived and used to obtain the optimal design, that is, the optimal predictor distribution, for the normative sample, thereby maximizing precision of estimation. This is done under five regression models with a quantitative and a categorical predictor, differing in whether they allow for interaction and nonlinearity. Efficient robust designs are given in case of uncertainty about the regression model. Furthermore, formulas are provided to compute the normative sample size such that individuals' positions relative to the derived norms can be assessed with prespecified power and precision. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Pragmatic Uncontrolled Study of Specialized Cognitive Behavioral Therapy for Adults With Chronic Tinnitus.

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 effects of their implementation on a large scale in routine practice remains unknown. Therefore, the main purpose of this study was to examine the effects of stepped-care cognitive behavioral therapy for tinnitus delivered in a tertiary audiological center of a regional hospital. Second, we wished to examine predictors of favorable outcome. DESIGN: Four hundred three adults with chronic tinnitus were enrolled in this prospective observational study (at 3 months, N=334, 8 months, N=261; 12 months, N=214). The primary outcome was health-related quality of life as measured by the Health Utilities Index III (HUI-III) at 12 months. Secondary outcomes were self-reported levels of tinnitus-related distress, disability, affective distress and tinnitus-related negative beliefs and fear. Measures were completed pre-intervention at 3 months, 8 months, and 12 months. Multilevel modeling was used to examine effects and their predictors. RESULTS: Younger participants with lower levels of tinnitus distress were more likely to dropout while those with higher tinnitus distress at baseline and quality of life were more likely to receive step 2 of treatment. MLM analyses revealed, with one exception, no relation between any baseline variable and outcome change over time. Most participants' improvement exceeded minimally clinical important difference criteria for quality of life, tinnitus-related handicap, and tinnitus distress. CONCLUSIONS: Results from this large pragmatic study complements those from randomized controlled trials of cognitive behavioral therapy for chronic tinnitus distress and supports its implementation under "real-world" conditions.

Laparoscopic versus open resections in the posterosuperior liver segments within an enhanced recovery programme (ORANGE Segments): study protocol for a multicentre randomised controlled trial.

BACKGROUND: A shift towards parenchymal-sparing liver resections in open and laparoscopic surgery emerged in the last few years. Laparoscopic liver resection is technically feasible and safe, and consensus guidelines acknowledge the laparoscopic approach in the posterosuperior segments. Lesions situated in these segments are considered the most challenging for the laparoscopic approach. The aim of this trial is to compare the postoperative time to functional recovery, complications, oncological safety, quality of life, survival and costs after laparoscopic versus open parenchymal-sparing liver resections in the posterosuperior liver segments within an enhanced recovery setting. METHODS: The ORANGE Segments trial is an international multicentre randomised controlled superiority trial conducted in centres experienced in laparoscopic liver resection. Eligible patients for minor resections in the posterosuperior segments will be randomised in a 1:1 ratio to undergo laparoscopic or open resections in an enhanced recovery setting. Patients and ward personnel are blinded to the treatment allocation until postoperative day 4 using a large abdominal dressing. The primary endpoint is time to functional recovery. Secondary endpoints include intraoperative outcomes, length of stay, resection margin, postoperative complications, 90-day mortality, time to adjuvant chemotherapy initiation, quality of life and overall survival. Laparoscopic liver surgery of the posterosuperior segments is hypothesised to reduce time to functional recovery by 2 days in comparison with open surgery. With a power of 80% and alpha of 0.04 to adjust for interim analysis halfway the trial, a total of 250 patients are required to be randomised. DISCUSSION: The ORANGE Segments trial is the first multicentre international randomised controlled study to compare short- and long-term surgical and oncological outcomes of laparoscopic and open resections in the posterosuperior segments within an enhanced recovery programme. TRIAL REGISTRATION: ClinicalTrials.gov NCT03270917 . Registered on September 1, 2017. Before start of inclusion. PROTOCOL VERSION: version 12, May 9, 2017.

Imputation of Missing Covariates in Randomized Controlled Trials with Continuous Outcomes: Simple, Unbiased and Efficient Methods.

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, where the covariate of interest (treatment group) is independent of all baseline (pre-randomization) covariates due to randomization. This has been shown in the literature, but only for missingness on a single baseline covariate. Here, we extend the situation to multiple baseline covariates with missingness and evaluate the performance of MI and ML compared with simple alternative methods under various missingness scenarios in RCTs with a quantitative outcome. We first derive asymptotic relative efficiencies of the simple methods under the missing completely at random (MCAR) scenario and then perform a simulation study for non-MCAR scenarios. Finally, a trial on chronic low back pain is used to illustrate the implementation of the methods. The results show that all simple methods give unbiased treatment effect estimation but with increased mean squared residual. It also turns out that mean imputation and the missing-indicator method are most efficient under all covariate missingness scenarios and perform at least as well as MI and LM in each scenario.

Maximin design of cluster randomized trials with heterogeneous costs and variances.

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 the design stage and can differ between treatment arms. As a solution, this paper presents a Maximin design that maximizes the minimum relative efficiency (relative to the optimal design) over the variance parameter space, for trials with two treatment arms and a quantitative outcome. This maximin relative efficiency design (MMRED) is compared with a published Maximin design which maximizes the minimum efficiency (MMED). Both designs are also compared with the optimal designs for homogeneous costs and variances (balanced design) and heterogeneous costs and homogeneous variances (cost-conscious design), for a range of variances based upon three published trials. Whereas the MMED is balanced under high uncertainty about the treatment-to-control variance ratio, the MMRED then tends towards a balanced budget allocation between arms, leading to an unbalanced sample size allocation if costs are heterogeneous, similar to the cost-conscious design. Further, the MMRED corresponds to an optimal design for an intraclass correlation (ICC) in the lower half of the assumed ICC range (optimistic), whereas the MMED is the optimal design for the maximum ICC within the ICC range (pessimistic). Attention is given to the effect of the Welch-Satterthwaite degrees of freedom for treatment effect testing on the design efficiencies.

A randomized controlled trial comparing community lifestyle interventions to improve adherence to diet and physical activity recommendations: the VitalUM study.

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. Participants (n = 1,629), aged 45-70 years, randomly selected and recruited in 2005-2006 from 23 Dutch general practices, were randomized (centralized stratified allocation) to four groups to receive a 12-month lifestyle intervention targeting guideline adherence for PA and fruit and vegetable consumption. Study groups received either four computer-tailored print communication (TPC) letters (n = 405), four telephone motivational interviewing (TMI) sessions (n = 407), a combined intervention (two TPC letters and two TMI sessions, n = 408), or no intervention (control group, n = 409). After the baseline assessment, all parties were aware of the treatment groups. Outcomes were measured with self-report postal questionnaires at baseline, 25, 47 and 73 weeks. For PA, all three interventions were associated with better guideline adherence than no intervention. Odds ratios for TPC, TMI and the combined intervention were 1.82 (95% CI 1.31; 2.54), 1.57 (95% CI 1.13; 2.18), and 2.08 (95% CI 1.50; 2.88), respectively. No pedometer effects were found. For fruit and vegetable consumption, TPC seemed superior to those in the other groups. Odd ratio for fruit and vegetable consumption were 1.78 (95% CI 1.32; 2.41) and 1.73 (95% CI 1.28; 2.33), respectively. For each behaviour, adherence was predicted by self-efficacy expectations, habit strength and stages of change, whereas sex, awareness and the number of action plans predicted guideline adherence for fruit and vegetable intake. The season predicted the guideline adherence for PA and fruit consumption. The odds ratios revealed were equivalent to modest effects sizes, although they were larger than those reported in systematic reviews. This study indicated that less resource intensive interventions might have the potential for a large public health impact when widely implemented. The strengths of this study were the participation of lower educated adults and evaluation of maintenance effects. (Trial NL1035, 2007-09-06).

Optimal two-stage sampling for mean estimation in multilevel populations when cluster size is informative.

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 (informative cluster size), the following competing sampling designs are considered: sampling clusters with probability proportional to cluster size, and then the same number of individuals per cluster; drawing clusters with equal probability, and then the same percentage of individuals per cluster; and selecting clusters with equal probability, and then the same number of individuals per cluster. For each design, optimal sample sizes are derived under a budget constraint. The three optimal two-stage sampling designs are compared, in terms of efficiency, with each other and with simple random sampling of individuals. Sampling clusters with probability proportional to size is recommended. To overcome the dependency of the optimal design on unknown nuisance parameters, maximin designs are derived. The results are illustrated, assuming probability proportional to size sampling of clusters, with the planning of a hypothetical survey to compare adolescent alcohol consumption between France and Italy.

The perceived behavior and barriers of community care professionals in encouraging functional activities of older adults: the development and validation of the MAINtAIN-C questionnaire.

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 study, the MAINtAIN questionnaire, which was developed for nursing homes, was adopted. The objective was to create a modified version that is suitable for measuring behavior and barriers of community care professionals in encouraging functional activities of clients in the community care setting. The overall aims were to assess the content validity, construct validity, and internal consistency of the modified version. METHODS: Data was collected by qualitative and quantitative methods in two phases. During phase one, the MAINtAIN was assessed on appropriateness and feasibility by community nurses (N = 7), and the adapted questionnaire was assessed on content validity by research experts (N = 9) and community care professionals (N = 18). During phase two, the psychometric properties of the adapted MAINtAIN-C were assessed in community care professionals (N = 80). Construct validity was evaluated by an Exploratory Factor Analysis (EFA), and internal consistency was determined by calculating Cronbach's alpha coefficients. RESULTS: The formulation, verbs, and wording of the MAINtAIN were adapted; some items were excluded and relevant items were added, resulting in the MAINtAIN-C with two scales, showing good content validity. The Behaviors scale (20 items) measures perceived behavior in encouraging functional activities, expressing good internal consistency (Cronbach's alpha: .92). The Barriers scale measures barriers in encouraging functional activities related to two dimensions: 1) the clients' context (7 items), with good internal consistency (.78); and 2) the professional, social, and organizational contexts (21 items), showing good internal consistency (.83). CONCLUSIONS: The MAINtAIN-C seems promising to assess the behavior and barriers of community care professionals in encouraging functional activities. It can be used to display a possible difference between perceived and actual behavior, to develop strategies for removing barriers in encouraging activities to foster behavioral change. The results also provide guidance for further research in a larger sample to obtain more insight into the psychometric properties.

Imputation of missing covariate in randomized controlled trials with a continuous outcome: Scoping review and new results.

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 imputation (MI) with various simple alternative methods. This is finally extended to the case of time-to-event outcome. The simulations consider five different missingness scenarios: missing completely at random (MCAR), at random (MAR) with missingness depending only on the treatment, and missing not at random (MNAR) with missingness depending on the covariate itself (MNAR1), missingness depending on both the treatment and covariate (MNAR2), and missingness depending on the treatment, covariate and their interaction (MNAR3). Here, we distinguish two different cases: (1) when the covariate is measured before randomization (best practice), where only MCAR and MNAR1 are plausible, and (2) when it is measured after randomization but before treatment (which sometimes occurs in nonpharmaceutical research), where the other three missingness mechanisms can also occur. The proposed methods are compared based on the treatment effect estimate and its standard error. The simulation results suggest that the patterns of results are very similar for all missingness scenarios in case (1) and also in case (2) except for MNAR3. Furthermore, in each scenario for continuous outcome, there is at least one simple method that performs at least as well as MI, while for time-to-event outcome MI is best.

Aquatic Cycling Improves Knee Pain and Physical Functioning in Patients With Knee Osteoarthritis: A Randomized Controlled Trial.

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 (OA). DESIGN: Two-arm, single-blind, parallel-group randomized controlled trial. SETTINGS: OA outpatient clinic of the Maastricht University Medical Center+. PARTICIPANTS: Patients (N=111, 50-70y) with unilateral mild-to-moderate knee OA. INTERVENTIONS: Participants (aquatic cycling [AC] group, n=55) received AC sessions of 45 min each 2 times per week. Each session combined upright seated cycling with out-of-saddle positions and exercises for the upper and lower body. The usual care (UC) group (n=47) continued with UC and was offered 12 AC sessions in a local swimming pool after their trial participation. MAIN OUTCOME MEASURES: The Knee Injury and Osteoarthritis Outcome Score (KOOS) on knee pain and physical function was assessed at baseline, postintervention, and at 24-wk follow-up. Multilevel (mixed regression) analysis examined the effects. RESULTS: Average attendance rate for the AC sessions was 80%. Statistically significant differences at postintervention and follow-up were found for knee pain in mean ± SD (UC pretest, 57.89±15.26; posttest, 55.90±18.04; follow-up, 57.24±19.16; and AC pretest, 56.96±12.96; posttest, 63.55±15.33; follow-up, 64.35±17.26; estimate, 8.16; SE, 3.27; 95% confidence interval [CI], 1.67-14.64; effect size [ES], 0.50) and physical functioning (UC pretest, 66.32±16.28; posttest, 66.80±19.04; follow-up, 65.42±17.98; and AC pretest, 61.89±17.151; posttest, 70.14±17.52; follow-up, 69.00±16.84; estimate, 7.16; SE, 3.19; 95% CI, 0.83-13.49; ES, 0.43) in favor of the aquatic group. CONCLUSIONS: The results suggest that a 12-week AC training program improves self-reported knee pain and physical functioning in patients with mild-to-moderate knee OA compared to UC.

An overview of mixture modelling for latent evolutions in longitudinal data: Modelling approaches, fit statistics and software.

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 techniques, which includes an overview of their interrelatedness and applicability. Our focus will be on the commonly used model-based approaches which comprise latent class growth analysis (LCGA), group-based trajectory models (GBTM), and growth mixture modelling (GMM). We discuss criteria for model selection, highlight often encountered challenges and unresolved issues in model fitting, showcase model availability in software, and illustrate a model selection strategy using an applied example.

Borderline personality disorder traits and affect reactivity to positive affect induction followed by a stressor.

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 (seeking outpatient treatment for personality-related problems; yes/no), depressive symptoms, and age were examined as alternative predictors of affect reactivity. METHODS: One hundred and eight females (35 patients) reported on their BPD and depressive symptoms. They completed the Best Possible Self-exercise and a modified Trier Social Stress Task. Trajectories of high and low arousal PA (HAP and LAP) and negative affect (NA) were analyzed with mixed regression modelling. RESULTS: Patient status (for HAP) and depressive symptoms (for LAP and NA) predicted affect reactivity better than BPD traits. Patients showed a weaker HAP increase after PA-induction, and a similar HAP decrease after the stressor, compared to non-patients. Higher depressive symptoms predicted stronger improvement of LAP and NA after PA-induction, and less pronounced deterioration of LAP and NA after the stressor, relative to baseline. LIMITATIONS: The sample was a convenience sample amplified with outpatients. Future research should (1) use clinical groups, (2) randomize to neutral vs. PA-induction, and (3) continue to differentiate between HAP and LAP. CONCLUSIONS: Our results do not support models postulating BPD-specific affective hyperreactivity. HAP and LAP have different trajectories, depending on the degree of psychopathology. The resilience-enhancing potential of a PA-focus in psychotherapy needs further research.

A Longitudinal Study on the Relations Among Fear-Enhancing Parenting, Cognitive Biases, and Anxiety Symptoms in Non-clinical Children.

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/or fathers (n = 117). On each time point, children and parents completed the Parental Enhancement of Anxious Cognitions scale, which measures parental modeling and threat information transmission. Furthermore, children filled in a measure of anxiety disorder symptoms. In addition, confirmation bias and interpretation bias were measured by means of a number of computerized tasks. The results yielded support for a circular model in which cognitive biases enhanced anxiety symptoms, which in turn promoted cognitive biases on each of the three time points. However, no evidence was found for longitudinal effects of cognitive biases on anxiety or vice versa. In contrast to what we expected, cognitive biases and anxiety appeared to promote parental modeling and threat information rather than the other way around. These findings extend research on the relations between parenting behaviors, cognitive biases, and childhood anxiety symptoms, and suggest valuable leads for assessment and intervention.

Make a Move: A Comprehensive Effect Evaluation of a Sexual Harassment Prevention Program in Dutch Residential Youth Care.

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 very few interventions targeting this at-risk group, and no such programs exist in the Netherlands. To this end, a group intervention program-Make a Move-targeting determinants of sexual harassment was developed. This program was implemented and evaluated among boys ( N = 177) in Dutch residential youth care (20 institutions). A pre-test, post-test, and 6-month follow-up design including an intervention and a waiting list control group with randomized assignment of institutions (cluster randomized trial) was used to measure the effects of the intervention on determinants of sexual harassment. Multilevel (mixed) regression analysis with Bonferroni correction for multiple testing (α = .005) showed no significant effects of Make a Move on determinants of sexual harassment ( ps > .03, Cohen's ds < .44). Results are discussed in light of a three-way explanatory model focusing on intervention content, evaluation, and implementation as potential explanations for not finding any measurable intervention effects.