@article {karim2016comparison,
	title = {Comparison of Statistical Approaches for Dealing With Immortal Time Bias in Drug Effectiveness Studies},
	journal = {American Journal of Epidemiology},
	year = {2016},
	pages = {kwv445},
	publisher = {Oxford University Press},
	doi = {10.1093/aje/kwv445},
	author = {Karim, Mohammad Ehsanul and Gustafson, Paul and Petkau, John and Tremlett, Helen}
}
