What are the four types of misclassification bias?

What is Misclassification?

• Incomplete medical records.
• Recording errors in records.
• Misinterpretation of records.
• Errors in records, like incorrect disease codes, or patients completing questionnaires incorrectly (perhaps because they don’t remember (see: “recall bias“) or misunderstand the question).

What kind of bias is misclassification?

Misclassification bias is a systematic error that can occur at any stage in the research process. It occurs when an individual is assigned to a different category than the one to which they should be assigned (1).

Is differential or Nondifferential misclassification worse?

Nondifferential misclassification means that the frequency of errors is approximately the same in the groups being compared. Nondifferential misclassification of exposure is a much more pervasive problem than differential misclassification (in which errors occur with greater frequency in one of the study groups).

Is misclassification bias a type of information bias?

Major types of information bias are misclassification bias, observer bias, recall bias and reporting bias. It is a probable bias within observational studies, particularly in those with retrospective designs, but can also affect experimental studies.

Can a differential misclassification cause bias toward the null?

Since this is introduces a differential misclassification, it can cause bias either toward or away from the null, depending on the circumstances. Use standardized questionnaires consisting of closed-end, easy to understand questions with appropriate response options.

What causes differential misclassification in a systematic review?

Differential misclassification occurs when the probability of being misclassified differs between groups in a study (Porta et al. 2014). Included studies in a systematic review could use different classification systems, potentially causing misclassification bias when the studies are pooled in a meta-analysis.

When does bias occur in the direction of the null?

The direction of bias is away from the null if more cases are considered to be exposed or if more exposed are considered to have the health outcome. The effect of differential misclassification of the exposure or health outcome can bias the risk ratio, rate ratio, or odds ratio in either direction.

When does non-differential misclassification lead to incorrect associations?

This can lead to incorrect associations being observed between the assigned categories and the outcomes of interest. Non-differential misclassification occurs when the probability of individuals being misclassified is equal across all groups in the study.