estimate {ed50}

Estimate ED50

Description

Estimate 50 percent effective dose using different methods.

Usage

estimate(doseSequence, doseResponse, confidence = 0.95,
  method = c("Dixon-Mood", "Choi", "ModTurPoint", "Logistic",
  "Isotonic"), tpCiScale = 2.4/qnorm(0.975), boot.n = 10000)

Arguments

doseSequence

A sequence of doses given in order

doseResponse

A sequence of response results shown in order

confidence

The confidence level of interval estimate

method

The method used to estimate ED50, there are five methods here, respectively Dixon-Mood, Choi (Choi's Original Turning Point), ModTurPoint (Modified Turning Point), Logistic (Logistic Regression) and Isotonic (Isotonic Regression). The defaut is Dixon-Mood.

tpCiScale

The scale level to enlarge the confidence interval estimated by Modified Turning Point Method. The default value is 2.4/qnorm(0.975).

boot.n

The number of boot process if Logistic method is chosen to estimate ED50.

Value

A list of estimation result consisting of method of estimation, ED50 estimate, standard error of ED50 estimate, confidence level and estimate of confidence interval.

References

Dixon, W. J., & Mood, A. M. (1948). A method for obtaining and analyzing sensitivity data. Publications of the American Statistical Association, 43(241), 109-126. Choi, S. C. (1990). Interval estimation of the ld50based on an up-and-down experiment. Biometrics, 46(2), 485-492. Pace, N. L., & Stylianou, M. P. (2007). Advances in and limitations of up-and-down methodology: a precis of clinical use, study design, and dose estimation in anesthesia research. Anesthesiology, 107(1), 144-52.

Examples

library(ed50)
estimate(groupS$doseSequence, groupS$responseSequence, method = 'Dixon-Mood')
estimate(groupS$doseSequence, groupS$responseSequence, method = 'Logistic', boot.n = 1000)