A5022094855- Statistical Methods in Clinical Trials
- Optimal Experimental Design Methods
- Health Systems, Economic Evaluations, Quality of Life
- Evolution and Genetic Dynamics
- Advanced Multi-Objective Optimization Algorithms
- Economic and Social Issues
- Mathematical and Theoretical Epidemiology and Ecology Models
- Health and Medical Studies
- Education Methods and Technologies
- Biosimilars and Bioanalytical Methods
- Social and Demographic Issues in Germany
- Religion, Theology, and Education
- Consumer behavior in food and health
- Innovation, Technology, and Society
- Anesthesia and Neurotoxicity Research
- Corporate Governance and Management
- Advanced Statistical Process Monitoring
- Social Policies and Healthcare Reform
- Evolutionary Game Theory and Cooperation
- Gene Regulatory Network Analysis
- Amyloidosis: Diagnosis, Treatment, Outcomes
- Physical Activity and Health
- Corporate Social Responsibility and Sustainability
- Trauma and Emergency Care Studies
- Data Analysis with R
Charité - Universitätsmedizin Berlin
2019-2024
Humboldt-Universität zu Berlin
2019-2024
Freie Universität Berlin
2019-2024
Zimmer Biomet (Germany)
2020-2024
Heinrich Heine University Düsseldorf
2024
Berlin Institute of Health at Charité - Universitätsmedizin Berlin
2019-2020
State Environmental Service
2018
The COVID-19 pandemic led to the implementation of drastic shutdown measures worldwide. While quarantine, self-isolation and laws helped effectively contain control spread SARS-CoV-2, impact shutdowns on trauma care in emergency departments (EDs) remains elusive.
Due to the dependency structure in sampling process, adaptive trial designs create challenges point and interval estimation calculation of P ‐values. Optimal designs, which are where parameters governing adaptivity chosen maximize some performance criterion, suffer from same problem. Various analysis methods able handle this have already been developed. In work, we aim give a comprehensive summary these show how they can be applied class with planned adaptivity, optimal an important member....
Abstract Background Sample size calculation is a central aspect in planning of clinical trials. The sample calculated based on parameter assumptions, like the treatment effect and endpoint’s variance. A fundamental problem this approach that true distribution parameters are not known before trial. Hence, always contains certain degree uncertainty, leading to risk underpowering or oversizing One way cope with uncertainty adaptive designs. Adaptive designs allow adjust during an interim...
Recalculating the sample size in adaptive two‐stage designs is a well‐established method to gain flexibility clinical trial. Jennison and Turnbull (2015) proposed an “optimal” design based on inverse normal combination test, which minimizes mixed criterion of expected under alternative conditional power. We demonstrate that use test not necessary control type one error rate variational techniques develop general globally optimal predefined optimality criteria. This approach yields more...
Abstract Background In clinical trials with fixed study designs, statistical inference is only made when the trial completed. contrast, group sequential designs allow an early stopping of at interim, either for efficacy treatment effect significant or futility seems too small to justify a continuation trial. Efficacy boundaries based on alpha spending functions have been widely discussed in literature, and there also solid work choice adequate boundaries. Still, are often chosen little...
Adaptive designs are playing an increasingly important role in the planning of clinical trials. While there exists various research on optimal determination a two-stage design, non-optimal versions still frequently applied research. In this article, we strive to motivate application adaptive and give guidance how determine them. It is demonstrated that optimizing trial design with respect particular objective criteria can have substantial benefit over conventional sample size recalculation...
Abstract Background Statistical model building requires selection of variables for a depending on the model’s aim. In descriptive and explanatory models, common recommendation often met in literature is to include all which are assumed or known be associated with outcome independent their identification data driven procedures. An open question is, how reliable this “background knowledge” truly is. fact, “known” predictors might findings from preceding studies may also have employed...
BACKGROUND The cholinergic system is considered to play a key role in the development of postoperative delirium (POD), which common complication after surgery. OBJECTIVES To determine whether peri-operative acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities are associated with POD in-hospital surgical patients, raise hypotheses on regulatory mechanisms POD. DESIGN A prospective multicentre observational study by Peripheral Cholinesterase-activity Neurocognitive...
Even though adaptive two-stage designs with unblinded interim analyses are becoming increasingly popular in clinical trial designs, there is a lack of statistical software to make their application more straightforward. The package adoptr fills this gap for the common case one- or two-arm trials (approximately) normally distributed outcomes. In contrast previous approaches, optimizes entire design upfront which allows maximal efficiency. To facilitate experimentation different objective...
In standard clinical trial designs, the required sample size is fixed in planning stage based on initial parameter assumptions. It intuitive that correct choice of major importance for an ethical justification trial. The assumptions should be previously published results from literature. practice, however, historical data often do not exist or show highly variable results. Adaptive group sequential designs allow a recalculation after planned unblinded interim analysis order to adjust during...
"The limits of my language are the mind. All I know is what have words for" (Wittgenstein). When learning something completely new, we connect unknown term to an already existing part our knowledge. We can only build new ideas and insights upon conceptual foundation. In field statistics, educators frequently find ourselves met with great confusion when teaching novices. These students, entirely unfamiliar even basic must introduced statistical terms within their personal networks largely...
Limited research exists on pregnant women's knowledge, attitudes, and behavior concerning COVID-19 in sub-Saharan Africa. We performed a cross-sectional study among 648 women Fort Portal, Uganda, after the first lockdown starting June 2020. Structured interviews were conducted at three different facilities during routine antenatal care, assessing sociodemographic background, knowledge of COVID-19, prevention adherence, psycho-emotional stress levels. descriptive analyses examined associated...
Catalogs of competency-based learning objectives (CLO) were introduced and promoted as a prerequisite for high-quality, systematic curriculum development. While this is common in medicine, the consistent use CLO not yet well established epidemiology, biometry, medical informatics, biomedical nursing informatics especially Germany. This paper aims to identify underlying obstacles give recommendations order promote dissemination curricular development health data information sciences. To...
Many clinical trials assess time-to-event endpoints. To describe the difference between groups in terms of time to event, we often employ hazard ratios. However, ratio is only informative case proportional hazards (PHs) over time. There exist many other effect measures that do not require PHs. One them average (AHR). Its core idea utilize a time-dependent weighting function accounts for variation. Though propagated methodological research papers, AHR rarely used practice. facilitate its...
In group-sequential designs, it is typically assumed that there no time gap between patient enrollment and outcome measurement in clinical trials. However, practice, usually a lag the two points. This can affect statistical analysis of data, especially trials with interim analyses. One approach to address delayed responses has been introduced by Hampson Jennison (J R Stat Soc Ser B Methodol 75:3-54, 2013), who proposed use error-spending stopping boundaries for enrollment, followed critical...
In contrast to inherited transthyretin amyloidosis (A-ATTRv), neuropathy is not a classic leading symptom of wild type (A-ATTRwt). However, neurological symptoms are increasingly relevant in A-ATTRwt as well. To better understand the role A-ATTRwt, patients were prospectively characterized at Amyloidosis Center Charité Berlin (ACCB) between 2018 and 2023 using detailed examination, quality life questionnaires, analysis age- BMI-adapted serum neurofilament light chain (NFL) levels. 16 out 73...
Abstract Adaptive designs are an increasingly popular method for the adaptation of design aspects in clinical trials, such as sample size. Scoring different adaptive helps to make appropriate choice among numerous existing methods. Several scores have been proposed evaluate designs. Moreover, it is possible determine optimal two‐stage with respect a customized objective score by solving constrained optimization problem. In this paper, we use conditional performance Herrmann et al. (2020)...
If design parameters are chosen appropriately, group sequential trial designs known to be able reduce the expected sample size under alternative hypothesis compared single‐stage designs. The same holds true for so‐called ‘gold‐standard’ non‐inferiority trials, a involving an experimental group, active control and placebo group. However, choosing that maximize advantages of two‐stage approach three‐arm gold‐standard trials is not straightforward task. In particular, optimal choices futility...
Abstract Background An adequate sample size calculation is essential for designing a successful clinical trial. One way to tackle planning difficulties regarding parameter assumptions required adapt the during ongoing This can be attained by adaptive group sequential study designs. At predefined timepoint, interim effect tested significance. Based on test result, trial either stopped or continued with possibility of recalculation. Objectives Sample recalculation rules have different...
An amendment to this paper has been published and can be accessed via the original article.