What is the Origin of Surveillance Bias?

The concept originates from the field of epidemiology and biostatistics, highlighting a potential systematic error in the ascertainment of disease outcomes in comparative studies. It is a critical factor to consider when interpreting observational data, especially in long-term studies of hormonal interventions where frequent monitoring is standard practice. Researchers must account for this bias in their methodology.

What is the Mechanism of Surveillance Bias?

The mechanism of surveillance bias is differential scrutiny; the increased frequency of monitoring increases the probability of detecting an event, even if the underlying true incidence rate is the same across groups. For example, a patient on a new hormonal agent might receive more frequent liver function tests than a placebo patient, increasing the likelihood of detecting a transient, clinically insignificant elevation in liver enzymes.

Surveillance Bias ∞ Area

Surveillance Bias

Meaning

Surveillance bias is a type of information bias in clinical research and epidemiology where one group of individuals is monitored or screened more closely or frequently than another, leading to an artificially inflated rate of diagnosis in the more intensely observed group. In hormonal health, this bias can occur when patients on a specific hormone therapy are subjected to more frequent diagnostic testing, potentially detecting subclinical conditions that would have been missed in the control group. This can distort true safety profiles.