Table 1. Quartiles (25th, 50th, and 75th) of the distribution of incubation periods among anthrax cases by dose level of inhaled spores predicted by the competing-risks model.

	Incubation,* days
Toxic dose level	25th quartile	50th quartile (median)	75th quartile
Limiting†	4.1	9.9	19.8
TD(10)	3.9	9.5	19.2
TD(25)	3.6	8.9	18.3
TD(50)	3.1	7.7	16.2

^*In general, the q × 100 percentile of the incubation-period distribution at dose level TD(P) is -In[1 - (In(1 - qp)/In(1 - p))]/θ; q is set equal to 0.25, 0.50, and 0.75 at the quartiles.

^†Limit of the incubation period at low doses (p → 0) with clearance rate θ = 0.07/day.