| Abstract: | We present two truncated proportional hazards tests. The first, which is applicable to those cases in which the time of action of an agent or treatment is known, was studied in two forms: One uses expected Fisher information and the other observed Fisher information. In this case the expected information statistic, C1(a0), had properties superior to the observed information statistic and is recommended. The use of the X2 distribution with one degree of freedom for percentiles appears to be satisfactory. When the time of action is unknown, a statistic based on the maximum of the C1(a) statistics is used. A simulation study gives empirical percentiles for the Max C1(a) statistic which agree with those given in a study by Muenz, Green and Byar (1977). |
