Accession Number : AD0731397

Title :   One- and Two-Stage Models for Comparing an Experimental Treatment with a Standard.

Descriptive Note : Technical rept.,

Corporate Author : HARVARD UNIV CAMBRIDGE MASS DEPT OF STATISTICS

Personal Author(s) : Donner,Allan P.

Report Date : 08 OCT 1971

Pagination or Media Count : 27

Abstract : Optimal one- and two-stage plans are developed for selecting one of two medical treatments, an experimental treatment A or a standard treatment B. The response to treatment is normally distributed with unknwon mean mu sub A or mu sub B and known variance sigma squared. It is assumed mu sub A > or = mu sub B but that treatment A is worthwhile adopting only if mu sub A - mu sub B > or = a, where a is fixed. The only cost considered is the ethical one of treating a patient with the 'wrong' treatment. Out of a total of N patients with the disease in question, a fraction 2P of them is to be placed in a clinical trial comparing the two treatments, with the 'winning' treatment to be given to the remaining N(1-2P) patients. Optimal values of P are found for both a one-stage and a two-stage plan, with the latter showing a modest improvement in expected net gain. The case in which mu sub B is known is also considered, and the resultant improvement in expected net gain over the case mu sub B unknown is found to moderate for a one-stage trial. (Author)

Descriptors :   (*THERAPY, *STATISTICAL ANALYSIS), SEQUENTIAL ANALYSIS, CORRELATION TECHNIQUES, STATISTICAL TESTS, PROBABILITY, DISTRIBUTION FUNCTIONS, COMPUTER PROGRAMS

Subject Categories : Medicine and Medical Research
      Statistics and Probability

Distribution Statement : APPROVED FOR PUBLIC RELEASE