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Sample Size & Power Calculations
Calculate for a Variety of frequentist and Bayesian Design

Adaptive Design
Design and Analyze a Wide Range of Adaptive Designs

Milestone Prediction
Predict Interim Analysis Timing or Study Length

Randomization Lists
Generate and Save Lists for your Trial Design


Group Sequential and Promising Zone Designs
Calculate Boundaries & Find Sample Size. Evaluate Interim Data & Re-estimate Sample Size

Sample Size for Bayesian Statistics
Probability of Success (Assurance), Credible Intervals, Bayes Factors and more

Early Stage and Complex Designs
Sample size & operating characteristics for Phase I, II & Seamless Designs (MAMS)

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Receive Regulatory Approval

nQuery helps biostatisticians consistently calculate the appropriate sample size for FDA/EMA submission

Free 14 day trial

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Reducing the risk & cost of clinical trials, for innovative organizations such as:
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Sample Size For Regulatory Approval

Consistently calculate correct sample size for FDA/EMA submission

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Whether designing a clinical trial or putting together a study proposal, sample size determination is an integral part of the study planning process. With over 20 years of experience in clinical trial design, when using nQuery you can trust that your sample size determination is being conducted to the highest regulatory standards.

With hundreds of tables for different study designs and tests you can be confident that you will have a validated sample size determination method appropriate for your study. In our sample size software, each sample size table is thoroughly tested and fully validated against the latest regulatory requirements.

Using the academic literature and in conjunction with experts in the field and regulatory agencies we ensure that each table in nQuery is using the latest and most accurate methods possible for that sample size determination scenario.

Validated Sample Size Software

We also compare the results against other sample size software in the field to ensure there is consistency in the validated results. Thanks to this, nQuery has become an industry standard for over 20 years and is widely used and trusted by regulatory agencies such as the FDA for sample size determination in clinical trials.

Sample Size Output Statement

After you've completed your sample size determination in nQuery, you will often wish to communicate your results with regulatory agencies or funding bodies. To assist you in this nQuery provides the output statement.

The output statement is a verbal summary of the sample size determination results that you calculated in nQuery. This can then provide a template which can be added to your study protocol or study proposal and then edited to reflect the specifics of your trial.

Installation Qualification/ Operational Qualification

In regulated environments, it is required that all software has been fully qualified. To assist in this nQuery provides the installation qualification and operational qualification tools. The installation qualification tool ensures that all of the files that are expected are present and that their integrity has been maintained.

The operational qualification tool ensures that every calculation used in nQuery is still giving the same results as expected through our internal testing. Both of these tools are designed to be easy to use and intuitive and to provide results that can be easily read by anyone in the organization.

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Successful Trials
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Real studies demonstrated in nQuery 

  • Classical, Bayesian & Adaptive examples
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