COMPUTATIONAL METHODS FOR EVALUATING SEQUENTIAL TESTS AND POST-TEST ESTIMATION VIA THE SUFFICIENCY PRINCIPLE

By the sufficiency principle, the probability density of a sequential test statistic under certain conditions can be factored into a known function that does not depend on the stopping rule and a conditional probability that is free of un- known parameters. We develop general theorems and propose a unified approach to analyzing and evaluating various properties of sequential tests and post-test es- timation. The proposed approach is of practical value since it allows for effective evaluation of properties of special interest, such as the bias-adjustment of post-test estimation after a sequential test, and the probability of discordance between a sequential test and a nonsequential test.

[1]  T. Fleming,et al.  Parameter estimation following group sequential hypothesis testing , 1990 .

[2]  T. W. Anderson A MODIFICATION OF THE SEQUENTIAL PROBABILITY RATIO TEST TO REDUCE THE SAMPLE SIZE , 1960 .

[3]  K. K. Lan,et al.  Stochastically curtailed tests in long–term clinical trials , 1982 .

[4]  Christopher Jennison,et al.  Numerical Computations for Group Sequential Tests , 1999 .

[5]  KyungMann Kim Group Sequential Methods with Applications to Clinical Trials , 2001 .

[6]  D L DeMets,et al.  Interim analysis: the alpha spending function approach. , 1994, Statistics in medicine.

[7]  Patrick Billingsley,et al.  Probability and Measure. , 1986 .

[8]  B. Turnbull,et al.  Group Sequential Methods with Applications to Clinical Trials , 1999 .

[9]  P. Spreij Probability and Measure , 1996 .

[10]  T. Lai,et al.  A Nonlinear Renewal Theory with Applications to Sequential Analysis II , 1977 .

[11]  John Whitehead,et al.  On the bias of maximum likelihood estimation following a sequential test , 1986 .

[12]  T. Lai Sequential Tests for Hypergeometric Distributions and Finite Populations , 1979 .

[13]  P. Armitage,et al.  Repeated Significance Tests on Accumulating Data , 1969 .

[14]  Xiaoping Xiong,et al.  Absorption probability distributions of Random paths from finite populations , 1996 .

[15]  T. Lai SEQUENTIAL ANALYSIS: SOME CLASSICAL PROBLEMS AND NEW CHALLENGES , 2001 .

[16]  E. Samuel-Cahn Repeated significance test II, for hypotheses about the normal distribution , 1974 .

[17]  M Tan,et al.  Clinical trial designs based on sequential conditional probability ratio tests and reverse stochastic curtailing. , 1998, Biometrics.

[18]  J. Whitehead,et al.  A FORTRAN program for the design and analysis of sequential clinical trials. , 1983, Computers and biomedical research, an international journal.

[19]  T. Lai,et al.  First Exit Time of a Random Walk from the Bounds $f(n) \pm cg(n)$, with Applications , 1979 .

[20]  H. Wieand,et al.  The bias of the sample proportion following a group sequential phase II clinical trial. , 1989, Statistics in medicine.

[21]  Leo A. Aroian,et al.  Sequential Analysis, Direct Method , 1968 .

[22]  Xiaoping Xiong,et al.  A Class of Sequential Conditional Probability Ratio Tests , 1995 .