I am trying to use a glm with a binomial distribution (logit link) to analyse data from a dose response curve for the lethal effects of different bacterial strains. I now want to obtain estimates of the lethal dose 50 (LD50).
My model is simply of the form:
survival ~ a + b*dose
Thus since I have a logit link, obtaining the estimates for the LD50 (i.e. p=0.5) simply means dividing -a/b. However, I am also wanting to know the confidence intervals for these estimates and that's where I am unsure about what to do. If anyone would have a suggestion for this, that would be great.