nQuery is a software to calculate the sample size of a planned study. It offers procedures for various types of outcomes (continuous, categorical, time-to-event) in statistical tests or regression models. It supports studies of measurement agreement and of non-inferiority or equivalence testing as well as multi-phase (group sequential) studies with interim analyses.
The software allows to produce graphs (power curves depending on sample size or study-specific parameters like standard deviation) and to automatically generate a completely formulated justification of the calculated sample size.
nQuery is available at the MedUni Vienna as “Campus-Lizenz” from the ITSC (in German). The software is used worldwide in academic research and is approved by registration agencies. Compared to freely available internet-based programmes nQuery has the advantage that the methods employed are reliably tested, transparent and supported by references.
Consultation for sample size planning of planned clinical studies is offered by the CeMSIIS Institutes of Clinical Biometrics (Tel. secr.: 40400-66880) and of Medical Statistics ( Tel. secr.: 40400-74880).