Healthy worker (user) bias needs to be considered when performing an epidemiologic study.
Possible bias types: selection, information, confounding
The bias occurs when:
(1) findings in a group compared to a general population
(2) the group is healthier than the general population, with a lower mortality rate
While the group may be healthier as a whole, its members may be:
(1) exposed to more hazardous conditions
(2) have a different age distribution in its members
Examples of a group with healthier members:
(1) construction or industrial workers
(2) military soldiers
(3) sports group
"Healthy worker" is relevant to occupational epidemiological studies. one
The bias may be subtle. It is avoided during the study design by taking steps to recognize and to correct for it. Unfortunately, many methods have limitations. Li and Sung recommend use of external work comparison and internal comparison groups.
