Statistical power analysis and sample size determination are crucial elements of study design. A study that is too small may produce inconclusive results, while a study that is too large will waste scarce resources. nTerim provides power and sample size calculations for group sequential trials. nTerim uses the alpha-spending function of Lan & DeMets and includes the spending functions from O’Brien-Fleming, Pocock, Hwang-Shih-DeCani and others.
- Excellent tools for system analysis and design
- It is quite expensive