@article{Shrank2011,
author = {Shrank, W.H. and Patrick, A.R. and Brookhart, M.A.},
title= {Healthy user and related biases in observational studies of preventive interventions: A primer for physicians},
year = {2011},
doi = {10.1007/s11606-010-1609-1},
URL = {https://doi.org/10.1007/s11606-010-1609-1},
volume = {26},
number = {5},
pages = {546‒550},
}