Confidence Intervals for Asbestos Fiber Counts: Approximate Negative Binomial Distribution.

ABSTRACT: The negative binomial distribution is adopted for analyzing asbestos fiber counts so as to account for both the sampling errors in capturing only a finite number of fibers and the inevitable human variation in identifying and counting sampled fibers. A simple approximation to this distribution is developed for the derivation of quantiles and approximate confidence limits. The success of the approximation depends critically on the use of Stirling's expansion to sufficient order, on exact normalization of the approximating distribution, on reasonable perturbation of quantities from the normal distribution, and on accurately approximating sums by inverse-trapezoidal integration. Accuracy of the approximation developed is checked through simulation and also by comparison to traditional approxi

SUBMITTER: Bartley D 

PROVIDER: S-EPMC5619260 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature