. Author manuscript; available in PMC: 2017 Jun 1.

Published in final edited form as: Endoscopy. 2016 Apr 4;48(6):571–578. doi: 10.1055/s-0042-104116

Table 2.

EPoS power^*

		10 year CRC incidence (proportion)
	Power	P1 proportion	P2 proportion	Group size	Total sample size
EPoSI	80%	0.01	0.015	4897	9794
EPoSI	90%	0.01	0.015	6783	13566
EPoS II	80%	0.02	0.027	4947	9894
EPoS II	90%	0.02	0.027	6852	13704

P1 is the control group (shorter surveillance intervals), P2 is the intervention group (longer surveillance intervals).

Sample size needed to exclude a difference between the control group and the intervention group of 0.5% or more for EPoS I and 0.7% or more for EPoS II