Table 3 Relevant forms of algorithmic biases

From: Bias recognition and mitigation strategies in artificial intelligence healthcare applications

Bias

Definition

Example

Aggregation bias

An inappropriate combination of distinct groups or populations during data pre-processing for model development leads to aggregation bias, where the model’s performance is only optimized for the majority. In other words, one single model is unlikely to suit all groups.

Machine learning clinical prediction studies may not adequately handle missing data, leading to aggregation bias. This uniquely affects model performance among subgroups less likely to have complete data resources43.

Feature selection bias

When the set of features chosen to train a model do not adequately represent the underlying problem or are not equally relevant across all subpopulations within the dataset.

AI models developed for COVID-19 patient risk prediction, triage, and contact tracing have shown feature selection bias through inadequate representation or consideration of social determinants of health (SDOH), such as race, socio-economic status, and access to technology. The underrepresentation of these factors has led to biased outcomes, particularly those most vulnerable or marginalized95.