Thank you;but,am afraid that does not help me much. However;if a RR of less than 2 is considered not to be reliable or significant, and ORs give higher numbers,below what number is a OR considered to be not significant? Gary K.
If the probabilities of the events are small enough for second order terms to be neglected, as they are here, the OR and RR may be considered equal; so the criterion applies in the same way.
The OR is just there for the purposes of obscurantism.