Related Experiment Video
Updated: Mar 28, 2026

Measuring the Subjective Value of Risky and Ambiguous Options using Experimental Economics and Functional MRI Methods
Published on: September 19, 2012
Evaluating the Risk of Bias of a Study
1Department of Periodontology and Operative Dentistry, Faculty of Dentistry, University of Münster, Waldeyerstraße 30, 48149 Münster, Germany.
Objective:
This first article of a series of 4 is aimed at guiding dental practitioners on how to evaluate the internal validity (risk of bias,) of randomized controlled trials (RCT). All RCT's contain different areas and potential sources of bias. Understanding risk of bias (ROB) will allow dental practitioners to improve the quality of dental treatments.
Methods:
The following areas of bias were elucidated: sequence generation, allocation concealment, blinding of participants and personnel, blinding of outcome assessment, incomplete outcome data, selective reporting, and "other bias". The reader determines the ROB level by evaluating the areas or potential source of bias in the first phase. Normally, ROB levels are classified as low, high and unclear ROB.
Results:
This article reported the concepts and methods of evaluation of ROB in several areas of an RCT. An RCT with low ROB in all evaluated areas gives the dental practitioners more certainty and confidence that a specific clinical procedure is in fact effective and relevant to the patient.
Conclusions:
The information provided here may guide dental practitioners in the evaluation of ROB in an RCT. The correct evaluation of ROB may improve the quality of dental treatments.
Related Concept Videos
Bias in Epidemiological Studies
Bias
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...
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
Accuracy and Errors in Hypothesis Testing
In hypothesis testing, the probability of making a Type I error, denoted as α, is commonly set at 0.05. This significance level indicates a 5%...
Blind Procedures
Confounding in Epidemiological Studies

