Diagnostic Accuracy Studies in Radiology: How to Recognize and Address Potential Sources of Bias
Table 1
Types of bias in diagnostic accuracy studies and how to address them.
Bias type
How to address
Spectrum bias
Perform random or consecutive sampling; avoid excluding subjects with ambiguous results
Information bias
Implement blinding of the researchers to the results of the reference test when interpreting the index test; predetermine the thresholds when designing a study
Misclassification bias
Predict the direction and degree of deviation for the diagnostic accuracy in sensitivity analysis and adjust accordingly; create a composite reference standard
Diagnostic review bias
Implement blinding of the researchers to the results of the index test when interpreting the reference test
Incorporation bias
Address in the limitations section the possibility of overestimation of accuracy estimates and if possible, adjust accordingly
Verification bias
Use the same reference standard for all subjects and if not possible, acknowledge and measure the potential accuracy estimate error
Attrition bias
Study the characteristics of subjects lost and how they differ from those that remain; perform sensitivity analysis to calculate the range of diagnostic accuracy estimates as if all withdrawals tested positive or negative
