Sample Size Software Compared….nQuery Advisor Vs. Siz

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How Does nQuery Advisor Compare with Siz from Cytel?

In the comparison sheet that Cytel have used to compare nQuery Advisor and SiZ they have used three headings; Design, Simulation and Analysis.nQuery Advisor does not perform any statistical analysis, it is purely used for calculating power and sample size.
Also, nQuery Advisor uses closed form solutions for calculating sample size as much as possible, thereby eliminating the need for nQuery Advisor to perform simulations. Certain tables require simulation (for example with survival analysis) and where appropriate nQuery Advisor provides this.

In the SiZ document, there are several entries that refer to Non-inferiority/Superiority/Equivalence. In nQuery Advisor there are tables for equivalence for difference of means, ratio of means, difference of proportions. nQuery Advisor labels these tables as Equivalence but by setting the limits appropriately they can all be used for Non-Inferiority and Superiority also. There are examples of this in the nQuery Advisor manual. So it is a little misleading to say nQuery Advisor does not include these tables. The calculations can be done, they are just all under the heading of Equivalence.

nQuery Advisor also contains tables for calculating sample size for Survival Analysis, Agreement and Regression, none of which are present in SiZ. Here is a full list of the tables that nQuery Advisor offers:

http://www.statistical-solutions-software.com/nquery-advisor-sample-size-software/sample-size-tables/

Finally, the SiZ document lists an incorrect price for nQuery Advisor. nQuery Advisor is priced as follows: Academic Licenses US$795 / Euro 650 and Commercial Licenses US$995 / Euro 895. These prices are for perpetual licenses and no annual fees are payable.