How to review audit trails


The FDA regularly issues warning letters regarding data integrity. Now, the agency is encouraging companies involved in GMP to get on top of these issues with regular audit trail review. You may have read some FDA or EU publications relating to data integrity and audit trails and wondered how they may apply to your organization. This article will demystify audit trail review and provide you an outline for your organization’s data integrity initiative.

What is an audit trail? What are some other data integrity terms?

Audit trail means “a secure, computer-generated, time-stamped electronic record that allows for reconstruction of the course of events relating to the creation, modification, or deletion of an electronic record. An audit trail is a chronology of the ‘who, what, when, and why’ of a record.”

The usefulness and power of the audit trail can vary quite a bit by system. In an older hemocytometer for example, you may find that there is no audit trail – the printout containing the time, date, result, and sample name is the extent of the data produced by the machine.

In the case of a newer analytical instrument such as a mass spectrometer, you will find that the audit trail is exhaustive and essentially unalterable. It will be a dynamic, all-inclusive record that displays information about every user and instrument action, in a human-readable format. It may be searchable by date, user, type of action, etc. It may even be in its own view-only, data manager module for ease of use. It may be exportable as an Excel file or printable as a PDF.

Another instrument may be intermediate in user-friendliness: you can display a page or two of printable, static information surrounding a specific file or sample, but cannot easily search or scroll.

Audit trails are part of a broader concept called metadata. “Metadata is the contextual information required to understand data.” For example, a set of data may be a list of compounds and their concentrations in a sample. The metadata surrounding this data would include the username, time and date, the data path (where the files are automatically saved), any error messages that came up, and any changes to the sample name. As outlined above, the extent of the metadata collected by the system can vary quite a bit.

An even broader concept is data integrity. This term refers to “the completeness, consistency, and accuracy of data. Complete, consistent, and accurate data should be attributable, legible, contemporaneously recorded, original or a true copy, and accurate (ALCOA).”

A concrete analogy

To make data integrity a little more concrete, consider how you treat crossouts on a paper record. Most crossouts are justified (mistakes happen). But when someone does make a crossout to update a raw data entry, your organization’s SOPs require them to address it. They do this by drawing a single line through the original entry (leaving it still legible). They then need to provide an explanation (such as “incorrect entry”) along with the identity of the person who did the correction, and the date of the correction.

In this way the date and recorder of the original entry, the date and recorder of the correction, and the reason for the correction are all documented. In addition the original entry remains legible for comparison to the corrected entry.

Data integrity refers to these same controls but in a digital format. And reviewing audit trails helps the Quality unit to review these deletions and changes in the same way they review them on paper.

Everyone in your organization plays a part in ensuring data integrity. Reviewing audit trails is part of that effort.

Where do I start?

Start by looking at the list of all computerized systems in your organization. If you have no such list, make one! A spreadsheet is adequate.

Classify each system by what regulated activity it is used for (GMP, GLP, etc.) and by its criticality. Document who is the system administrator (i.e. who controls access and sets up and deactivates users). Identify the subject matter expert who can answer your questions (see below). Sort the systems by criticality. Audit trail review is resource-intensive, so you will want to start with the critical ones.

Do a brief, informal review with a regular user of the system. See if you can easily access the audit trail from the main screen of the program or if you need to log into a separate module such as a data manager, security module, or report mode.

Audit trail functionality may have been documented in the validation. Check the validation paperwork for hints on how to access it. Check the manufacturer’s materials as well.

Consider the feasibility and resource-intensiveness of audit trail review for each system. Does reviewing it mean booting someone off the terminal? Is there a limited number of user licenses? All these considerations will influence the requirements you define in your data integrity SOP.

Take notes and write down any questions to address during a more detailed review to follow. Update the spreadsheet you started.

An assessment of each system is needed

This involves a more detailed assessment. A member of the Quality unit will sit down for about an hour with one subject matter expert in the software/instrument. In advance, you will want to come up with a template Word document with items to address. The idea is to get accurate information, including screenshots, to help with training and crafting the SOP. Topics may include the following:

What type of audit trail is it?

• Is it a dynamic event log, capturing every action automatically? Or does it just display the parameters of the individual run?
• Can the reviewer select a date range?
• Can he or she search by user, batch or project number?
• Are there any error messages for the subject matter expert to look into? Are there error messages that qualify as red flags for the reviewer?
• Does the audit trail capture when a user edits a sample name or lot number? When critical parameters are changed? When background scans are re-run? When the results from standards are rejected?
• What do manipulations and deletions look like? Is there a way to compare versions of a file?
• In analytical chemistry, is there an audit trail for acquisition of data, but no audit trail for processing of data? In chromatography, is there a way to compare integrations of peaks? What does excessive integration look like, and is this something the Quality unit should review?
• Compare records from a recent project or run to what you see onscreen in the audit trail. Go step by step and write down some typical audit trail events.

Don’t duplicate the effort of the original validation. But do look at the system through a data integrity mindset.

You may find that routine audit trail review opens new conversations about a system. Although an audit trail cannot be “corrected,” review of the audit trail may point to deficiencies elsewhere in the project’s documentation.

For example, if one person signed the batch record, lab notebook or worksheet, but the audit trail shows a different user (such as a trainer) performing that procedure, then both signatures should be in the documentation.

Another example is retesting or reprocessing: if the audit trail clearly shows a retest, but this was not documented, then this should be addressed in the documentation before Quality unit approval of the record.

For legacy systems, make sure any deficiencies are documented and that alternative data integrity measures are in place

You may look at an older instrument or software and find it is not 21CFR11 compliant, or not compliant in the way you thought it was. You can add a brief risk assessment to the validation paperwork with a memo referencing the new audit trail review procedure that is being put in place.

Look to the manufacturer’s compliance software

If the software is older, ask the vendor about updates. They may have released a data security module that you can add to the software. If there is no audit trail functionality, the system may still be Part 11 compliant. Don’t worry – audit trail functionality is not an absolute Part 11 requirement.

Get access for the QA reviewer for each system

Once this assessment is complete, get the Quality reviewer access to each system.

Some software will have a reviewer (read-only) mode. This is ideal because they will not be able to accidentally delete a file or alter a method. If the Quality reviewer is a standard user, that’s fine too!

Efficiency side note: to avoid duplication of effort, the periodic review can be reduced somewhat in scope.

Although audit trails will now be reviewed routinely, the periodic review is still important because this is where failed login attempts, periodic vendor maintenance, and changes to the overall method are captured. Keep in mind the risk-based approach.

Write the SOP!

Reference information technology SOPs, validation SOPs, ethics and training SOPs, and Quality review SOPs. Make sure it has caveats that address the range of software at your company. This procedure should involve organization-wide training. Having an executive or director champion it would be very valuable. Everyone should know what is expected of them with respect to data integrity.

Revisit this procedure in a year

To follow up, continue reviewing FDA warning letters for the agency’s thinking on data integrity matters. Distribute the pertinent letters to your team. Connect the audit trail reviewers with those involved with equipment/software validations so that audit trails are set up and understood proactively. Even better, ask for the reviewers’ input on the next set of compliance software that the vendor is trying to sell you.

A year after effectivity, revisit this procedure and see how it’s going:

• Is it too impractical? Are reports being delayed because the reviewer can’t get into the system while others are logged on?
• Is system access an issue? Does only one person in the Quality unit have the needed access?
• If you have technical data reviewers and a Quality reviewer, are they duplicating each other’s review? It can be hard to separate a technical review from a procedural review. Perhaps only one group should review.
• Look at the overall value of the project. If you find that reviewing audit trails in the way recommended in the FDA’s draft guidance is not a value-added step, let the FDA know! Now is the time to comment before the draft guidance becomes a requirement.

Lastly, take the long and broad view. Consider audit trail review to be one of many tools in your organization’s data integrity efforts. Keep in mind that other organizations are grappling with these issues as well, and there are no experts out there who have all the answers. You will have to treat data integrity as an ongoing commitment, with every data integrity procedure open to change, optimization and improvement.

If you have had successes, failures or questions in your audit trail efforts, I’d love to hear about them!

Mississippi River St Paul Feb 2017

Explore further

Data Integrity and Compliance With CGMP Guidance for Industry (draft guidance). The FDA published this in April 2016 as draft guidance. But as we know, you need to get ahead of the guidance!



This FDA slideshow, released a year later, provides some helpful elaboration on the guidance:



This article provides an concise summary of the challenges of starting an audit trail review process, and the importance of a risk-based approach based on an assessment of each system. The link opens a PDF:


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