Stata is verifiably accurate

When you submit new drug applications (NDAs), the U.S. Food and Drug Administration (FDA) requires you to verify the validity of your data and analyses. The FDA guidance document can be found at http://www.fda.gov/ora/compliance_ref/bimo/ffinalcct.htm

According to this document, to demonstrate the validity of the software used for an NDA, you must have

1. a written design specification;
   
   
2. a test plan; and
   
   
3. test results.

Stata provides all three:

1. An extensive set of manuals detailing the syntax, use, formulas, references, and examples for all of the commands in Stata
   
   
2. An extensive software certification suite consisting of over 500,000 lines of code testing the computational validity of Stata’s commands and Stata’s ability to maintain integrity
   
   
3. The output from running Stata’s test suite on all supported platforms (Windows, Mac, Unix, etc.)
   
   The test suite produces over 1 million lines of output as of 15 February 2006. This output is electronically compared to previous runs of the test suite and against runs on other platforms. Any differences are examined and resolved by our statisticians and software engineers before a new release of Stata (or any subsequent free updates) is sent to users.
   
   The actual number of tests is even larger than is indicated above. Many of the tests do not produce output but instead quietly do the computations and compare them with the correct results. If results are outside accepted tolerance levels, the test fails.
   
   Also see http://www.stata.com/support/cert/ for information about Stata’s results running the National Institute of Standards (NIST) StRD numerical accuracy tests and the George Marsaglia Diehard random-number generator tests.

The FDA guidance document further discusses change/version control and documentation of revalidation. All updates to Stata can be obtained by users over the Internet with the simple Stata command update. All changes are documented in Stata’s help system. Users can type help whatsnew to see, listed by date, all changes that have been made to Stata and included in the currently installed update (as well as previous updates).

Stata has an excellent worldwide reputation for accuracy and quick resolution of all questions. Should any questions arise about using Stata when submitting to any government agency (including the FDA), StataCorp will assist you in resolving the issues by working directly with the government agency, if needed.