The influence of prevalent cohort bias in the association between periodontal disease progression and incident coronary heart disease.
Heaton Brenda, Applebaum Katie M, Rothman Kenneth J, +4 more·Annals of epidemiology
PURPOSE: In longitudinal studies, the onset of the index condition (e.g. exposure) does not always coincide with the start of a study's observation period, leading to the possibility of bias in estimation that derives from studying prevalent exposure rather than new exposure. We investigate the possible role of this bi…