A model-based correction for outcome reporting bias in meta-analysis

John Copas1, Kerry Dwan, Jamie Kirkham

  • 1Department of Statistics, University of Warwick, Coventry CV4 7AL, UK.

Insights

Outcome reporting bias (ORB) in medical trials can significantly skew results. This study proposes a model to correct for ORB, showing that adjusted findings move towards the null, potentially overturning significance claims.

Area of Science:

  • Medical Research Methodology
  • Biostatistics
  • Evidence Synthesis

Background:

  • Selective outcome reporting is a known issue in medical trials.
  • This bias can lead systematic reviews to omit studies with non-significant results for certain outcomes.
  • Existing systematic reviews may overestimate treatment effects due to this bias.

Purpose of the Study:

  • To develop a statistical model for estimating the impact of outcome reporting bias (ORB) on meta-analysis results.
  • To quantify the effect of ORB on confidence intervals and p-values.
  • To provide a method for correcting ORB in systematic reviews.

Main Methods:

  • Utilized the methodology from the Outcome Reporting Bias (ORB) in Trials study.
  • Developed a likelihood-based statistical model to estimate bias.
  • Re-analyzed two contrasting examples of meta-analyses.

Main Results:

  • Correcting for ORB shifts estimated treatment effects towards the null hypothesis.
  • The bias can be substantial, potentially reversing conclusions of statistical significance.
  • A simple fixed-effects approximation was derived for practical estimation of ORB effects.

Conclusions:

  • Outcome reporting bias significantly impacts the reliability of meta-analyses.
  • Adjusting for ORB leads to more conservative and accurate assessments of treatment efficacy.
  • The proposed model and approximation offer tools to mitigate the effects of ORB in evidence synthesis.

Related Concept Videos

Strategies for Assessing and Addressing Confounding01:25

Strategies for Assessing and Addressing Confounding

Confounding is a critical issue in epidemiological studies, often leading to misleading conclusions about associations between exposures and outcomes. It occurs when the relationship between the exposure and the outcome is mixed with the effects of other factors that influence the outcome. Given that, addressing confounding is of high importance for drawing accurate inferences in research.
Confounding can be addressed at both the design phase of a study and through analytical methods after data...
606
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches01:23

Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches

Biopharmaceutical studies constitute a vital field aiming to enhance drug delivery methods and refine therapeutic approaches, drawing upon diverse interdisciplinary knowledge. In research methodologies, the choice between controlled and non-controlled studies significantly influences the study's reliability and accuracy.
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
631
Mechanistic Models: Compartment Models in Individual and Population Analysis01:23

Mechanistic Models: Compartment Models in Individual and Population Analysis

Mechanistic models are utilized in individual analysis using single-source data, but imperfections arise due to data collection errors, preventing perfect prediction of observed data. The mathematical equation involves known values (Xi), observed concentrations (Ci), measurement errors (εi), model parameters (ϕj), and the related function (ƒi) for i number of values. Different least-squares metrics quantify differences between predicted and observed values. The ordinary least...
360
Bias01:22

Bias

Bias refers to any tendency that prevents a question from being considered unprejudiced. In research, bias occurs when one outcome or answer is selected or encouraged over others in sampling or testing. Bias can occur during any research phase, including study design, data collection, analysis, and publication.
In statistics, a sampling bias is created when a sample is collected from a population, and some members of the population are not as likely to be chosen as others (remember, each member...
6.2K
Bias in Epidemiological Studies01:29

Bias in Epidemiological Studies

Biases can arise at various stages of research, from study design and data collection to analysis and interpretation. Recognizing and addressing these biases is essential to ensure the validity and reliability of epidemiological findings.Broadly speaking, biases in epidemiology fall into three main categories: selection bias, information bias, and confounding. A more detailed description of possible biases is:  
1.7K
Methods of Medium Optimization01:28

Methods of Medium Optimization

Optimizing growth media enhances microbial proliferation and maximizes product yield. Statistical experimental design methodologies provide structured and reproducible approaches, offering progressively higher levels of robustness and efficiency.The One-Factor-at-a-Time (OFAT) MethodThe One-Factor-at-a-Time (OFAT) method involves adjusting a single variable while keeping all others constant. However, it cannot detect interactions between variables, often leading to suboptimal outcomes when...
74