Using StatXact to calculate tolerance intervals in studies with Poisson outcomes

Article type: Research Article

Authors: Zaslavsky, Boris G.

Affiliations: FDA, 1401 Rockville Pike HFM-219, Rockville, MD 20852, USA. Tel.: +1 301 827 8587; Fax: +1 301 827 5218; E-mail: [email protected]

Abstract: The mathematical theory of tolerance intervals for distributions with Poisson outcomes is well developed. One criticism is the relative difficulty of computing the Poisson tolerance intervals, particularly when approximate formulae are not applicable. We offer the computational algorithm for the exact upper and lower tolerance intervals founded on the estimate of the exact confidence limits for the Poisson rate. Thus the exact tolerance intervals may be calculated using StatXact. To illustrate the algorithm, we apply it to the analysis of transfusion – associated deaths.

Keywords: Clinical trial, confidence probability, Poisson distribution, StatXact, tolerance limit

DOI: 10.3233/MAS-2009-0112

Journal: Model Assisted Statistics and Applications, vol. 4, no. 2, pp. 117-122, 2009