Abstract:

AIM: To explore the sample size calculation by control global power for multiple rates as multi endpoints in single-arm Objective Performance Criteria (OPC) trials. METHODS: Based on the sample size calculations for single-arm OPC with single endpoint, we illustrated the statistical principle of sample size calculations with multi endpoints in theory and proposed a method by control global power. According to the pre-determined level of OPC, target value, type I error and total type II error, the power of each endpoint could be evaluated under the given sample sizes and the multiplication of all powers was the actual global power. The sample size reached objective global power was evaluated by the stepwise search method. RESULTS: We compared the sample sizes using the conventional direct power correction and stepwise search method through an example of one-sample clinical trial with four proportions based on normal approximation method and exact method. The results showed that the latter could more accurately control the global power and reduced the sample sizes. CONCLUSION: We proposed a solution to correct sample sizes for single-arm OPC trials with multi endpoints, which could control global power and reduce sample sizes significantly.

Key words: objective performance criteria, multi endpoints, sample size, global power, stepwise search method