LOW-DOSE-RATE EXTRAPOLATION OF DATA FROM ANIMAL CARCINOGENICITY EXPERIMENTS - ANALYSIS OF A NEW STATISTICAL TECHNIQUE
LOW-DOSE-RATE EXTRAPOLATION OF DATA FROM ANIMAL CARCINOGENICITY EXPERIMENTS - ANALYSIS OF A NEW STATISTICAL TECHNIQUE
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DOI:
10.1016/0025-5564(76)90051-1
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发表时间:
1976-01-01
影响因子:
4.3
通讯作者:
CRUMP, KS
中科院分区:
文献类型:
--
作者:
GUESS, HA;CRUMP, KS
Use of data from animal experiments to estimate the human cancer risk due to long-term exposure to low doses of chemicals in the environment poses a number of biological and statistical problems. One of the statistical problems is to extrapolate the animal dose-response relation from the high dose range where test data are available to low doses, which humans might encounter. The mathematical properties of a new technique for performing this extrapolation were developed. (Strictly speaking, it is an interpolation, since some animals are always tested at the background dose as a control.) The technique is based on maximum likelihood estimation of parameters in dose-response relations whose form is derived from a general multistage carcinogenesis model. Since the number of stages is itself an unknown, the number of parameters to be estimated is infinite, although only finitely many will be nonzero for any given set of data. Existence and uniqueness properties of the estimates are proved using results of Karlin and Studden and Krein and Rehtman from the theory of interpolation of polynomials with nonnegative coefficients. The algorithm for calculating the estimates is based on reducing an infinite set of Kuhn-Tucker conditions to an equivalent finite set of conditions, by exploiting properties of lexicographic ordering. This paper deals with the mathematical properties of the estimation technique. Statistical properties will be discussed in a subsequent paper.