A note on reference limits

We introduce a conceptual framework within which the problem of setting reference intervals is one of estimating population parameters. The framework enables us to broaden the possibilities for inference by showing how to create confidence intervals for population intervals. We propose a new kind of interval (the γ-mode interval) as the population parameter of interest and show how to estimate and make optimal inference about this interval. Finally, we clarify the relationship between our reference intervals and other types of intervals.