Biostatistics Core

The Biostatistics Core, part of the Division of Biomedical Statistics and Informatics, provides comprehensive biostatistics consulting and analysis services to Mayo Clinic investigators at all stages of the research process.

A large range of project types are supported by the core, including genetic analyses, clinical trials, outcomes research and clinical studies with individual Mayo Clinic departments. As needed, the core works to develop and refine statistical methods and software.

Read more about the core.


Concept development and protocol design

In the early phases of a study, investigators will have identified a case series of interest or a hypothesis to be answered. They often have questions about ideal sample size; optimal study design, such as a case-control study versus a cohort study; and whether a comparison population is needed.

At this stage, the statistician will:

  • Evaluate potential biases due to inclusion and exclusion criteria or case ascertainment
  • Discuss and highlight advantages or disadvantages of various study designs that can be used to address the research question
  • Estimate the required number of subjects needed to answer the hypothesis with sufficient power or determine the minimal effect difference that can be detected if the sample size is predetermined
  • Identify appropriate statistical analyses and methodologies that are best suited for the research objectives
  • Assist in protocol and grant development, including writing the statistical methods section and creating a statistical budget, prior to its submission to the Mayo Clinic Institutional Review Board (IRB), departmental research committee or the National Institutes of Health
Data collection

Once the IRB has approved the research protocol, data abstraction can get under way.

At this point, the statistician will:

  • Assist in the design of the data abstraction, including identifying variables to collect and defining variable fields
  • Discuss and highlight the various ways to enter data into an analyzable database, such as by using paper forms, online entry systems or other methods
  • Create online entry systems as needed
  • Identify electronic sources of data to reduce manual abstraction
  • Monitor clinical trials for adverse events and data quality
Data analysis and reporting

Upon completing the data abstraction effort, data analysis and reporting of results can begin.

During this phase, the statistician will:

  • Coordinate team members and biostatistical resources to address the analysis needs
  • Verify the research authorization status of all study subjects and log this information with the IRB
  • Identify and report any data discrepancies or errors in abstraction that need to be addressed and oversee the data correction process
  • Perform the statistical analyses as outlined in the protocol
  • Summarize and interpret the results of the statistical analyses in relation to the research objective or hypothesis
  • Assist in developing abstracts, manuscripts, and oral or poster presentations to ensure appropriate conclusions are reached
  • Verify the accuracy of reported results prior to submission to journals or professional meetings


Jean-Pierre A. Kocher, Ph.D.
Core Director and Chair, Division of Biomedical Statistics and Informatics

Mayo Clinic
200 First St. SW
Rochester, MN 55905