Articles

Using Bayesian statistics to estimate the likelihood a new trial will demonstrate the efficacy of a new treatment

The common frequentist approach is limited in providing investigators with appropriate measures for conducting a new trial. To answer such important questions and one has to look at Bayesian statistics.

Authors: David J. Biau, Samuel Boulezaz, Laurent Casabianca, Moussa Hamadouche, Philippe Anract and Sylvie Chevret

Why statistical inference from clinical trials is likely to generate false and irreproducible results

One area of biomedical research where the replication crisis is most visible and consequential is clinical trials. Why do outcomes of so many clinical trials contradict each other? Why is the effectiveness of ...

Authors: Leonid Hanin

Methods for significance testing of categorical covariates in logistic regression models after multiple imputation: power and applicability analysis

Multiple imputation is a recommended method to handle missing data. For significance testing after multiple imputation, Rubin’s Rules (RR) are easily applied to pool parameter estimates. In a logistic regressi...

Authors: Iris Eekhout, Mark A. van de Wiel and Martijn W. Heymans

Estimating correlation between multivariate longitudinal data in the presence of heterogeneity

Estimating correlation coefficients among outcomes is one of the most important analytical tasks in epidemiological and clinical research. Availability of multivariate longitudinal data presents a unique oppor...

Authors: Feng Gao, J. Philip Miller, Chengjie Xiong, Jingqin Luo, Julia A. Beiser, Ling Chen and Mae O. Gordon

The impact of self-interviews on response patterns for sensitive topics: a randomized trial of electronic delivery methods for a sexual behaviour questionnaire in rural South Africa

Self-interviews, where the respondent rather than the interviewer enters answers to questions, have been proposed as a way to reduce social desirability bias associated with interviewer-led interviews. Compute...

Authors: Guy Harling, Dumile Gumede, Tinofa Mutevedzi, Nuala McGrath, Janet Seeley, Deenan Pillay, Till W. Bärnighausen and Abraham J. Herbst

Applied Swarm-based medicine: collecting decision trees for patterns of algorithms analysis

The objective consensus methodology has recently been applied in consensus finding in several studies on medical decision-making among clinical experts or guidelines. The main advantages of this method are an ...

Authors: Cédric M. Panje, Markus Glatzer, Joscha von Rappard, Christian Rothermundt, Thomas Hundsberger, Valentin Zumstein, Ludwig Plasswilm and Paul Martin Putora

The impact of the lookback period and definition of confirmatory events on the identification of incident cancer cases in administrative data

This cohort study examined the impact of the lengths of lookback and confirmation periods as well as the definition of confirmatory events on the number of incident cancer cases identified and age-standardized...

Authors: Jonas Czwikla, Kathrin Jobski and Tania Schink

Using classification and regression tree modelling to investigate response shift patterns in dentine hypersensitivity

Dentine hypersensitivity (DH) affects people’s quality of life (QoL). However changes in the internal meaning of QoL, known as Response shift (RS) may undermine longitudinal assessment of QoL. This study aimed...

Authors: Carolina Machuca, Mario V. Vettore, Marta Krasuska, Sarah R. Baker and Peter G. Robinson

Trading certainty for speed - how much uncertainty are decisionmakers and guideline developers willing to accept when using rapid reviews: an international survey

Decisionmakers and guideline developers demand rapid syntheses of the evidence when time sensitive evidence-informed decisions are required. A potential trade-off of such rapid reviews is that their results ca...

Authors: Gernot Wagner, Barbara Nussbaumer-Streit, Judith Greimel, Agustín Ciapponi and Gerald Gartlehner

Choice of futility boundaries for group sequential designs with two endpoints

In clinical trials, the opportunity for an early stop during an interim analysis (either for efficacy or for futility) may relevantly save time and financial resources. This is especially important, if the pla...

Authors: Svenja Schüler, Meinhard Kieser and Geraldine Rauch

Validity and reliability of a Malay version of the brief illness perception questionnaire for patients with type 2 diabetes mellitus

Illness perceptions involve the personal beliefs that patients have about their illness and may influence health behaviours considerably. Since an instrument to measure these perceptions for Malay population i...

Authors: Boon-How Chew, Rimke C. Vos, Monique Heijmans, Sazlina Shariff-Ghazali, Aaron Fernandez and Guy E. H. M. Rutten

Programme Reporting Standards (PRS) for improving the reporting of sexual, reproductive, maternal, newborn, child and adolescent health programmes

Information about design, implementation, monitoring and evaluation is central to understand the impact of programmes within the field of sexual, reproductive, maternal, newborn, child and adolescent health (S...

Authors: Anna E. Kågesten, Özge Tunçalp, Anayda Portela, Moazzam Ali, Nhan Tran and A. Metin Gülmezoglu

A mega-ethnography of eleven qualitative evidence syntheses exploring the experience of living with chronic non-malignant pain

Each year over five million people develop chronic non-malignant pain and can experience healthcare as an adversarial struggle. The aims of this study were: (1) to bring together qualitative evidence syntheses...

Authors: Fran Toye, Kate Seers, Erin Hannink and Karen Barker

A comparison of the conditional inference survival forest model to random survival forests based on a simulation study as well as on two applications with time-to-event data

Random survival forest (RSF) models have been identified as alternative methods to the Cox proportional hazards model in analysing time-to-event data. These methods, however, have been criticised for the bias ...

Authors: Justine B. Nasejje, Henry Mwambi, Keertan Dheda and Maia Lesosky

A comparison of multiple imputation methods for handling missing values in longitudinal data in the presence of a time-varying covariate with a non-linear association with time: a simulation study

Missing data is a common problem in epidemiological studies, and is particularly prominent in longitudinal data, which involve multiple waves of data collection. Traditional multiple imputation (MI) methods (f...

Authors: Anurika Priyanjali De Silva, Margarita Moreno-Betancur, Alysha Madhu De Livera, Katherine Jane Lee and Julie Anne Simpson

Integrating data from randomized controlled trials and observational studies to predict the response to pregabalin in patients with painful diabetic peripheral neuropathy

More patient-specific medical care is expected as more is learned about variations in patient responses to medical treatments. Analytical tools enable insights by linking treatment responses from different typ...

Authors: Joe Alexander, Roger A. Edwards, Alberto Savoldelli, Luigi Manca, Roberto Grugni, Birol Emir, Ed Whalen, Stephen Watt, Marina Brodsky and Bruce Parsons

Basic parametric analysis for a multi-state model in hospital epidemiology

The extended illness-death model is a useful tool to study the risks and consequences of hospital-acquired infections (HAIs). The statistical quantities of interest are the transition-specific hazard rates and...

Authors: Maja von Cube, Martin Schumacher and Martin Wolkewitz

Binomial outcomes in dataset with some clusters of size two: can the dependence of twins be accounted for? A simulation study comparing the reliability of statistical methods based on a dataset of preterm infants

The analysis of perinatal outcomes often involves datasets with some multiple births. These are datasets mostly formed of independent observations and a limited number of clusters of size two (twins) and maybe...

Authors: Odile Sauzet and Janet L. Peacock

Implementing the EffTox dose-finding design in the Matchpoint trial

The Matchpoint trial aims to identify the optimal dose of ponatinib to give with conventional chemotherapy consisting of fludarabine, cytarabine and idarubicin to chronic myeloid leukaemia patients in blastic ...

Authors: Kristian Brock, Lucinda Billingham, Mhairi Copland, Shamyla Siddique, Mirjana Sirovica and Christina Yap

A random effects meta-analysis model with Box-Cox transformation

In a random effects meta-analysis model, true treatment effects for each study are routinely assumed to follow a normal distribution. However, normality is a restrictive assumption and the misspecification of ...

Authors: Yusuke Yamaguchi, Kazushi Maruo, Christopher Partlett and Richard D. Riley

A literature review of applied adaptive design methodology within the field of oncology in randomised controlled trials and a proposed extension to the CONSORT guidelines

The application of adaptive design methodology within a clinical trial setting is becoming increasingly popular. However the application of these methods within trials is not being reported as adaptive designs...

Authors: Pankaj Mistry, Janet A Dunn and Andrea Marshall

Nonlinear joint models for individual dynamic prediction of risk of death using Hamiltonian Monte Carlo: application to metastatic prostate cancer

Joint models of longitudinal and time-to-event data are increasingly used to perform individual dynamic prediction of a risk of event. However the difficulty to perform inference in nonlinear models and to cal...

Authors: Solène Desmée, France Mentré, Christine Veyrat-Follet, Bernard Sébastien and Jérémie Guedj

Protocol adherence for continuously titrated interventions in randomized trials: an overview of the current methodology and case study

The standard definition for protocol adherence is the proportion of all scheduled doses that are delivered. In clinical research, this definition has several limitations when evaluating protocol adherence in t...

Authors: F. Lauzier, N. K. Adhikari, A. Seely, K. K. Y. Koo, E. P. Belley-Côté, K. E. A. Burns, D. J. Cook, F. D’Aragon, B. Rochwerg, M. E. Kho, S. J. W. Oczkowksi, E. H. Duan, M. O. Meade, A. G. Day and F. Lamontagne

Clarifying the distinction between case series and cohort studies in systematic reviews of comparative studies: potential impact on body of evidence and workload

Distinguishing cohort studies from case series is difficult.

Authors: Tim Mathes and Dawid Pieper

Sample size re-estimation in paired comparative diagnostic accuracy studies with a binary response

The sample size required to power a study to a nominal level in a paired comparative diagnostic accuracy study, i.e. studies in which the diagnostic accuracy of two testing procedures is compared relative to a...

Authors: Gareth P. J. McCray, Andrew C. Titman, Paula Ghaneh and Gillian A. Lancaster

Using structural equation modeling for network meta-analysis

Network meta-analysis overcomes the limitations of traditional pair-wise meta-analysis by incorporating all available evidence into a general statistical framework for simultaneous comparisons of several treat...

Authors: Yu-Kang Tu and Yun-Chun Wu

Accounting for treatment use when validating a prognostic model: a simulation study

Prognostic models often show poor performance when applied to independent validation data sets. We illustrate how treatment use in a validation set can affect measures of model performance and present the uses...

Authors: Romin Pajouheshnia, Linda M. Peelen, Karel G. M. Moons, Johannes B. Reitsma and Rolf H. H. Groenwold

Cost and yield considerations when expanding recruitment for genetic studies: the primary open-angle African American glaucoma genetics study

African Americans have been historically under-represented in genetic studies. More research is needed on effective recruitment strategies for this population, especially on approaches that supplement traditio...

Authors: Rebecca Salowe, Laura O’Keefe, Sayaka Merriam, Roy Lee, Naira Khachatryan, Prithvi Sankar, Eydie Miller-Ellis, Amanda Lehman, Victoria Addis, Windell Murphy, Jeffrey Henderer, Maureen Maguire and Joan O’Brien

Inter-rater reliability of AMSTAR is dependent on the pair of reviewers

Inter-rater reliability (IRR) is mainly assessed based on only two reviewers of unknown expertise. The aim of this paper is to examine differences in the IRR of the Assessment of Multiple Systematic Reviews (AMST...

Authors: Dawid Pieper, Anja Jacobs, Beate Weikert, Alba Fishta and Uta Wegewitz

Implementation fidelity of a self-management course for epilepsy: method and assessment

Complex interventions such as self-management courses are difficult to evaluate due to the many interacting components. The way complex interventions are delivered can influence the effect they have for patien...

Authors: G. Wojewodka, S. Hurley, S. J. C. Taylor, A. J. Noble, L. Ridsdale and L. H. Goldstein

Data cleaning and management protocols for linked perinatal research data: a good practice example from the Smoking MUMS (Maternal Use of Medications and Safety) Study

Data cleaning is an important quality assurance in data linkage research studies. This paper presents the data cleaning and preparation process for a large-scale cross-jurisdictional Australian study (the Smok...

Authors: Duong Thuy Tran, Alys Havard and Louisa R. Jorm

Awareness of wearing an accelerometer does not affect physical activity in youth

This study aimed to investigate whether awareness of being monitored by an accelerometer has an effect on physical activity in young people.

Authors: Jérémy Vanhelst, Laurent Béghin, Elodie Drumez, Stéphanie Coopman and Frédéric Gottrand

Estimating parameters for probabilistic linkage of privacy-preserved datasets

Probabilistic record linkage is a process used to bring together person-based records from within the same dataset (de-duplication) or from disparate datasets using pairwise comparisons and matching probabilit...

Authors: Adrian P. Brown, Sean M. Randall, Anna M. Ferrante, James B. Semmens and James H. Boyd

Selection bias and subject refusal in a cluster-randomized controlled trial

Selection bias and non-participation bias are major methodological concerns which impact external validity. Cluster-randomized controlled trials are especially prone to selection bias as it is impractical to b...

Authors: Rochelle Yang, Barry L. Carter, Tyler H. Gums, Brian M. Gryzlak, Yinghui Xu and Barcey T. Levy

Barriers to publishing in biomedical journals perceived by a sample of French researchers: results of the DIAzePAM study

As publishing is essential but competitive for researchers, difficulties in writing and submitting medical articles to biomedical journals are disabling. The DIAzePAM (Difficultés des Auteurs à la Publication d’A...

Authors: Martin Duracinsky, Christophe Lalanne, Laurence Rous, Aichata Fofana Dara, Lesya Baudoin, Claire Pellet, Alexandre Descamps, Fabienne Péretz and Olivier Chassany

Inverse probability of treatment-weighted competing risks analysis: an application on long-term risk of urinary adverse events after prostate cancer treatments

To illustrate the 10-year risks of urinary adverse events (UAEs) among men diagnosed with prostate cancer and treated with different types of therapy, accounting for the competing risk of death.

Authors: Charlotte A. Bolch, Haitao Chu, Stephanie Jarosek, Stephen R. Cole, Sean Elliott and Beth Virnig

A DAG-based comparison of interventional effect underestimation between composite endpoint and multi-state analysis in cardiovascular trials

Composite endpoints comprising hospital admissions and death are the primary outcome in many cardiovascular clinical trials. For statistical analysis, a Cox proportional hazards model for the time to first eve...

Authors: Antje Jahn-Eimermacher, Katharina Ingel, Stella Preussler, Antoni Bayes-Genis and Harald Binder

Erratum to: Standardizing effect size from linear regression models with log-transformed variables for meta-analysis

Authors: Miguel Rodríguez-Barranco, Aurelio Tobías, Daniel Redondo, Elena Molina-Portillo and María José Sánchez

Simulation of complex data structures for planning of studies with focus on biomarker comparison

There are a growing number of observational studies that do not only focus on single biomarkers for predicting an outcome event, but address questions in a multivariable setting. For example, when quantifying ...

Authors: Andreas Schulz, Daniela Zöller, Stefan Nickels, Manfred E. Beutel, Maria Blettner, Philipp S. Wild and Harald Binder

Limitations of pulmonary embolism ICD-10 codes in emergency department administrative data: let the buyer beware

Administrative data is a useful tool for research and quality improvement; however, validity of research findings based on these data depends on their reliability. Diagnoses assigned by physicians are subseque...

Authors: Kristin Burles, Grant Innes, Kevin Senior, Eddy Lang and Andrew McRae

Bayesian hierarchical piecewise regression models: a tool to detect trajectory divergence between groups in long-term observational studies

Bayesian hierarchical piecewise regression (BHPR) modeling has not been previously formulated to detect and characterise the mechanism of trajectory divergence between groups of participants that have longitud...

Authors: Marie-jeanne Buscot, Simon S. Wotherspoon, Costan G. Magnussen, Markus Juonala, Matthew A. Sabin, David P. Burgner, Terho Lehtimäki, Jorma S. A. Viikari, Nina Hutri-Kähönen, Olli T. Raitakari and Russell J. Thomson

A nonparametric multiple imputation approach for missing categorical data

Incomplete categorical variables with more than two categories are common in public health data. However, most of the existing missing-data methods do not use the information from nonresponse (missingness) pro...

Authors: Muhan Zhou, Yulei He, Mandi Yu and Chiu-Hsieh Hsu

Methodologic considerations in the design and analysis of nested case-control studies: association between cytokines and postoperative delirium

The nested case-control study (NCC) design within a prospective cohort study is used when outcome data are available for all subjects, but the exposure of interest has not been collected, and is difficult or p...

Authors: Long H. Ngo, Sharon K. Inouye, Richard N. Jones, Thomas G. Travison, Towia A. Libermann, Simon T. Dillon, George A. Kuchel, Sarinnapha M. Vasunilashorn, David C. Alsop and Edward R. Marcantonio

Overview of systematic reviews of therapeutic ranges: methodologies and recommendations for practice

Many medicines are dosed to achieve a particular therapeutic range, and monitored using therapeutic drug monitoring (TDM). The evidence base for a therapeutic range can be evaluated using systematic reviews, t...

Authors: Lewis Cooney, Yoon K. Loke, Su Golder, Jamie Kirkham, Andrea Jorgensen, Ian Sinha and Daniel Hawcutt

Validity of self-reported weight and height: a cross-sectional study among Malaysian adolescents

Self-reported weight and height are commonly used in lieu of direct measurements of weight and height in large epidemiological surveys due to inevitable constraints such as budget and human resource. However, ...

Authors: C. C. Kee, K. H. Lim, M. G. Sumarni, C. H. Teh, Y. Y. Chan, M. I. Nuur Hafizah, Y. K. Cheah, E. O. Tee, Y. Ahmad Faudzi and M. Amal Nasir

Robust estimation of the expected survival probabilities from high-dimensional Cox models with biomarker-by-treatment interactions in randomized clinical trials

Thanks to the advances in genomics and targeted treatments, more and more prediction models based on biomarkers are being developed to predict potential benefit from treatments in a randomized clinical trial. ...

Authors: Nils Ternès, Federico Rotolo and Stefan Michiels

Duration of the common cold and similar continuous outcomes should be analyzed on the relative scale: a case study of two zinc lozenge trials

The relative scale has been used for decades in analysing binary data in epidemiology. In contrast, there has been a long tradition of carrying out meta-analyses of continuous outcomes on the absolute, origina...

Authors: Harri Hemilä

Changes in affect after completing a mailed survey about trauma: two pre- and post-test studies in former disability applicants for posttraumatic stress disorder

One potential concern with using mailed surveys containing trauma-related content is the possibility of re-traumatizing survivors without a trained mental health professional present. Prior research provides i...

Authors: Maureen Murdoch, Shannon Marie Kehle-Forbes and Melissa Ruth Partin

On the impact of nonresponse in logistic regression: application to the 45 and Up study

In longitudinal studies, nonresponse to follow-up surveys poses a major threat to validity, interpretability and generalisation of results. The problem of nonresponse is further complicated by the possibility ...

Authors: Joanna J. J. Wang, Mark Bartlett and Louise Ryan

On comparison of net survival curves

Relative survival analysis is a subfield of survival analysis where competing risks data are observed, but the causes of death are unknown. A first step in the analysis of such data is usually the estimation o...

Authors: Klemen Pavlič and Maja Pohar Perme