A linear dose response is a relationship between dose and biological response that is a straight line. In other words, the rate of change (slope) in the response is the same at any dose. A linear dose response is written mathematically as follows: if Y represents the expected, or average response and D represents dose, then

Y = aD

where a is the slope, also called the linear coefficient.

See also Dose response, Threshold dose, and Linear-quadratic dose response.