In a quantal dose-response assessment, which of the following is a typical endpoint?

• A. Death
• B. Maximum Concentration
• C. Rate of elimination
• D. Time to onset

Answer: (A)

In a quantal dose-response assessment, you’re looking at whether each individual in a population exhibits a predefined all-or-none effect after exposure. The endpoint should be a binary outcome—present or absent—for each subject so you can calculate the fraction affected at each dose. Death is the classic example because it is a clear, unambiguous yes/no outcome across individuals, making it straightforward to build a dose-response curve and determine metrics like LD50.

The other options describe exposure or timing measures rather than a binary effect: maximum concentration and rate of elimination are pharmacokinetic parameters that reflect how the body handles the dose, not whether an individual exhibits a fixed adverse effect. Time to onset indicates when an effect begins, which is a timing measure rather than a yes/no endpoint across the population.