Confidence Intervals for the Relative Relapse Rate of Placebo VS 6-Mercaptopurine Group of Acute Leukemia Patients Under a Random Censorship Model
✍ Scribed by B. Raja Rao; Sheela Talwalker; Debasis Kundu
- Publisher
- John Wiley and Sons
- Year
- 1991
- Tongue
- English
- Weight
- 873 KB
- Volume
- 33
- Category
- Article
- ISSN
- 0323-3847
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✦ Synopsis
The present paper considers a random censorhip model in which the remission times of acute leukemia patients in a study are randomly censored according to a given probability distribution and constructs confidence intervals for the Relative Relapee Rate [RRR] of the placebo versus 6-Mercaptopurine group of acute leukemia patients. Two important models are discussed for the prob-abiIity distributions of the remission timee-the exponential and the Weibull distributions. The censoring distributions are also regarded as following exponential and Weibull distributions. Several methods are used to construct the confidence intervals including its maximum likelihood estimator and its approximate sampling distribution. Sprott'e and cox's methods a8 well 88 the Box-Cox traneformations are also utilized.
Thesemethodaareusedtoilluetrate the constructionofthe confidence intervals with the FREIBEICH et al. data (1964) involving a placebo and a 6-MP group of acute leukemia patients. The results of the preaent paper provide valuable alternatives to the usual parametric and nonptarametric tests for the treatment effect, that are discussed in the literature, such as Gehan's test, Logrank test. and the Mantel-Haenszel test.
Key worh and phrases: Remission times; Censoring mechanism ; Control and treatment groups ; Exponential and Weibull distributions.