If you are designing a retrospective chart review, you should talk to a statistician early in the process. There are lots of statistical issues that you must think about during the concept development phase of your research. Here is a broad overview of these issues.

You should start off by taking advantage of the HIPAA regulations that allow for “Reviews preparatory to research.” The provisions of this regulation, found at 45 CFR 164.512(i)(1)(ii), allow you to review medical charts prior to getting IRB approval, if the purpose is to plan the research. According to the U.S. Department of Health and Human Services, preparatory to research means

“Representations from the researcher, either in writing or orally, that the use or disclosure of the protected health information is solely to prepare a research protocol or for similar purposes preparatory to research, that the researcher will not remove any protected health information from the covered entity, and representation that protected health information for which access is sought is necessary for the research purpose.” (HIPAA > For Professionals > Special Topics > Research).

There are several things that you can do here. You can investigate how many patient charts there are that might fit your inclusion criteria. There’s no point doing a retrospective chart review if you only have a couple of charts that you could use in the study. Depending on what you find, you can examine what impact modifications to the inclusion criteria or changes in the date ranges of your study have on the number of charts that you find. You can review the charts to see if the information that you need to abstract is available and easy to code.

All of these fall under the realm of feasibility. In addition to feasibility, you might also use the preparatory to research activities rule to refine your research question.

There are several important restrictions. Although you can (and should) do this work before getting your full protocol approved, you still have to make some “representation” that you are conducting a review preparatory to research. This might be as simple as a conversation with a member of your IRB, but some IRBs might ask you to fill out a form. Other IRBs will ask you to wait until the IRB approves that form. But even if your IRB has no requirements for reviews preparatory to research, you would be well advised to talk to someone and not make unwarranted assumptions about what this review might entail.

Also varying from institution to institution is how much you can do under the umbrella of reviews preparatory to research. The rules are pretty explicit that you can’t take any Protected Health Information (PHI) with you, but if you are employed by the “covered entity” that has these medical records, you might have a fair amount of latitude.

Some institutions have developed anonymized data repositories that you can also usei