Then if we throw a logarithm in there we should be seeking zero-centered intervals, I'm thinking, as opposed to non-negative intervals containing 1 (no effect).

Then if we throw a logarithm in there we should be seeking zero-centered intervals, I'm thinking, as opposed to non-negative intervals containing 1 (no effect). Any why normal distributions are even part of such discussions of ratios seems crazy, given that ratios can't be negative, but log-ratios can. Not my area; could it be that a log or similar non-linearity was already effectively included? If the confidence interval method was only using ratios, then the lower bound should have been zero, and negatives impossible. Sanity checking results shouldn't be so difficult.