Northwestern University Feinberg School of Medicine

Biostatistics Collaboration Center

Frequently Asked Questions (FAQ)

Following are responses to some of the frequently asked questions asked about the Biostatistics Collaboration Center (BCC).

What is the difference between advice about my statistical needs and statistical collaboration from the BCC?

Like other faculty members at Northwestern, the BCC statisticians are more than willing to offer brief general advice on statistical topics that may allow investigators to perform their work without extensive input from a statistician.  This is often possible with very straightforward problems.

However, when a statistician’s input requires substantial intellectual contributions to the conception, design, analysis, and/or interpretation of data for a research project or the final report of that work, we regard this as no longer simple “advice.” This represents true scientific collaboration.

Simple advice can generally be accomplished in a short period of time and is available at no direct charge to investigators since it is supported by the Feinberg’s infrastructure grant to the BCC. Collaboration requires more investment of time than the School is supporting from the grant to the BCC, and this level of involvement requires financial support of the BCC’s work on the project from the investigator who requests the consultation.

When is authorship on a paper considered appropriate by the BCC statisticians?

As with any paper, authorship is generally expected whenever substantive input on the design or analysis is provided. As for the BCC’s approaches to authorship, we endorse the criteria recommended by the International Committee of Medical Journal Editors ( These criteria state that authorship credit should be based on:

  1. Substantial contributions to conception and design, or acquisition of data, or analysis and interpretation of data;
  2. Drafting the article or revising it critically for important intellectual content; and
  3. Final approval of the version to be published.

Authors should meet all conditions.

Since the statistician often contributes to each of these three levels of intellectual and scientific involvement in manuscript preparation, we generally feel that authorship is appropriate for this kind of collaborative effort.

If I am paying for the statistician’s work, why should I also allow co-authorship of the paper as well?

The BCC policy states that authorship is separate entirely from payment.  Many research projects are supported by internal or external sponsors paying for the work involved.  In the case of the BCC statisticians, payment is more formalized than it may be with other collaborators, but no one may contribute to a project unless paid for the work.

Feinberg has established the BCC to make statistical consultation more readily available to investigators at Northwestern. There is no Feinberg policy allowing investigators to provide payment as a replacement for authorship.

When the BCC work is substantive, as outlined above, both payment for services and authorship on papers is justified.

How long will the project take?

You should expect to allow a reasonable time before deadlines. Remember that what appears to be a simple problem to you may not be. In the same way that you would want to be approached early in the process of preparing a new grant, the BCC faculty appreciate the same courtesy.

Might there be a charge for additional analysis?

Initial estimate of cost is done on the requested analysis, but additional charge will be required for any additional analysis or revision to the previous analysis due to the changes in the data, since new effort will be carried out for the new request. We make our best estimate of the work involved to be fair to ourselves and to investigators, but workload changes over time, and charges may change to reflect the added workload.  The BCC faculty/staff will communicate any additional charges.

What if I just want a second opinion?

Occasionally statisticians are asked for a second opinion on advice obtained elsewhere. There is a concern with getting a second opinion, as it is unlikely that you will be able to harmonize divergent advice. The BCC will advise an investigator looking for a second opinion to either stick to the first advice, using referees' comments if these are critical to obtain a revision of the analysis, or start again completely.

What if I have a last minute request?

We do not advise people to rely on being able to obtain advice at the last minute. Apart from the question of whether the answer to your problem is simple, you will not be the only person with a deadline to meet, and our workload may not allow that we can help you.  We prefer to plan ahead whenever possible.