This article explains the basic ideas and practical challenges in clinical trials of new medicines to show the practical application of statistics in the real-world. The article explores the key considerations for the objectives and design of clinical trials and how these relate to the statistical investigation process. The article also includes…

There exists a variety of interval estimators for the overall treatment effect in a random-effects meta-analysis. A recent literature review summarizing existing methods suggested that in most situations, the Hartung-Knapp/Sidik-Jonkman (HKSJ) method was preferable. However, a quantitative comparison of those methods in a common simulation study…

This note is concerned with evaluation of location parameters for polytomous items in multiple-component measuring instruments. A point and interval estimation procedure for these parameters is outlined that is developed within the framework of latent variable modeling. The method permits educational, behavioral, biomedical, and marketing…

Network meta-analysis is a popular method to synthesize the information obtained in a systematic review of studies (e.g., randomized clinical trials) involving subsets of multiple treatments of interest. The dominant method of analysis employs within-study information on treatment contrasts and integrates this over a network of studies. One…

Meta-analysis of individual participant data (IPD) is considered the "gold-standard" for synthesizing clinical study evidence. However, gaining access to IPD can be a laborious task (if possible at all) and in practice only summary (aggregate) data are commonly available. In this work we focus on meta-analytic approaches of comparative…

Introduction: The number of systematic reviews of health economic evaluations (SR-HEs) is increasing. We aimed at providing a detailed overview of the characteristics and applied methods in recently published SR-HEs. Methods: We searched MEDLINE (03/2017) for SR-HEs published since 2015 using validated search filters. We included studies that…

Meta-analyses often include only a small number of studies ([less than or equal to]5). Estimating between-study heterogeneity is difficult in this situation. An inaccurate estimation of heterogeneity can result in biased effect estimates and too narrow confidence intervals. The beta-binominal model has shown good statistical properties for…

This book offers practical guidance for understanding and implementing APA Style Journal Article Reporting Standards (JARS) and Meta-Analysis Reporting Standards (MARS) for quantitative research. These standards provide the essential information researchers need to report, including detailed accounts of the methods they followed, data results and…

When we speak about heterogeneity in a meta-analysis, our intent is usually to understand the substantive implications of the heterogeneity. If an intervention yields a mean effect size of 50 points, we want to know if the effect size in different populations varies from 40 to 60, or from 10 to 90, because this speaks to the potential utility of…

Objective: Various statistical methods have been developed to estimate hazard ratios (HRs) from published Kaplan-Meier (KM) curves for the purpose of performing meta-analyses. The objective of this study was to determine the reliability, accuracy, and precision of four commonly used methods by Guyot, Williamson, Parmar, and Hoyle and Henley.…

In meta-analysis, the random-effects model is often used to account for heterogeneity. The model assumes that heterogeneity has an additive effect on the variance of effect sizes. An alternative model, which assumes multiplicative heterogeneity, has been little used in the medical statistics community, but is widely used by particle physicists. In…

Background: The nursing profession is a combination of theory and practical skill, and nurses are required to generate and develop knowledge through implementing research into clinical practice. Considerable number of barriers could hind implementing research findings into practice. Barriers to research utilisation are not identified in the…

Objective: To obtain information on the current clinical research training status and evaluate the training needs comprehensively for medical staff in hospitals. Methods: This survey was initiated and conducted by the Health and Family Planning Commission of Shenzhen in conjunction with the Peking University Clinical Research Institute (Shenzhen)…

Background: Pupillometry has been studied as a physiological marker for quantifying cognitive load since the early 1960s. It has been established that small changes in pupillary size can provide an index of the cognitive load of an individual as he/she performs a mental task. The utility of pupillometry as a measure of expertise is less well…

Previous debate has explored whether medical education research should become more like health services research in terms of frameworks, collaborations and methodologies. Notable recent changes in health services research include an increasing emphasis on complex interventions, defined as interventions that involve more than one component. The…