ALCOA and Data Integrity: What Each Letter Actually Requires

ALCOA is the set of attributes a regulated record has to have. It is how FDA, MHRA and EMA describe what "trustworthy data" means, and it is the frame an investigator uses when auditing your records.

The original five, with the four later additions usually written ALCOA+:

• Attributable. Who did it, and when. A result with no identified operator is not attributable, and a shared login makes every record in that system unattributable at once.
• Legible. Readable, and permanent. Pencil fails. So does a system whose data cannot be read once the software is retired.
• Contemporaneous. Recorded as it happened. Writing the readings up at the end of the shift is a data integrity finding, not a documentation habit.
• Original. The first capture, or a verified true copy. The printout is not the original if the instrument holds the electronic record.
• Accurate. Correct, and free from unrecorded editing.

And the plus:

• Complete. Including repeats, failures and the data you did not like.
• Consistent. In sequence, with date and time stamps that agree.
• Enduring. Retained for the required period on durable media.
• Available. Retrievable for review throughout that period.

Why "complete" is the one that fails

Most data integrity findings are not fabrication. They are omission.

A failing result is investigated informally, the sample is rerun, and the second result is the one that reaches the batch record. Nothing was falsified. The record is still incomplete, and the out-of-specification investigation that should have happened did not.

The regulatory position is that you do not get to choose which data counts. Trial injections, aborted runs, and results invalidated without a documented scientific justification all belong in the record.

Audit trails

For computerised systems the audit trail is where ALCOA is proved or lost, and it is the first thing an investigator asks about at a pre-approval inspection.

The questions that decide it:

• Is the audit trail enabled? On some chromatography systems it ships off.
• Can it be disabled, and by whom? If an analyst holds administrator rights on the system that generates their own data, the segregation is broken.
• Is it reviewed? An audit trail nobody reads is a log, not a control. Review of the audit trail belongs in the batch record review.
• Does the system clock get changed, and is that change itself logged?

21 CFR Part 11 sets the requirements for electronic records and signatures in the United States. ALCOA is the plain-language test those requirements exist to satisfy.

What good looks like

Unique logins, no shared accounts, with rights matched to role.

Analysts do not administer the systems that hold their own results.

Second-person review covers the audit trail, not just the reported value.

Deviations and invalidated results are visible in the record, with the justification attached, rather than removed from it.