Why are there some genes with model fits but no BMDs?

There are several quality criteria applied to the BMDs to filter out low-confidence or otherwise undesirable BMD estimates:

  • Wide confidence interval: a wide confidence interval indicates a low-confidence estimate of the BMD. BMDs are eliminated if the BMDu/BMDl is greater than 40.
  • High dose extrapolation: BMDs that are higher than the highest dose are sometimes due to unpredictable model behaviour beyond the measured data (especially with higher order polynomials). BMDs are eliminated if they are greater than the highest dose.

Additionally, for some genes, the expression values never exceed the BMR and thus FastBMD cannot compute a BMD.