Understanding ALCOA+ Data Integrity for GLP Studies
Data integrity is the foundation of GLP compliance. Regulatory agencies worldwide use the ALCOA+ framework to evaluate whether study data is trustworthy:
Attributable: Every data point must identify who generated it, when, and on what system. Electronic audit trails must capture user ID and timestamp for every action.
Legible: Data must be readable throughout its retention period. Handwritten data in permanent ink; electronic data in accessible formats. Corrections use single-line strikethrough — the original must remain readable.
Contemporaneous: Data recorded at the time of the activity. FDA inspectors compare instrument timestamps against study schedules to detect backdating.
Original: First recording or a certified true copy. "Transcribing" from unofficial notes to official forms is a common audit finding.
Accurate: Verified calculations, calibrated instruments, and consistent units. Selective reporting (cherry-picking favorable data) is a critical finding.
Complete, Consistent, Enduring, Available (the + in ALCOA+): No deleted data without justification, no contradictions between related records, durable storage media, and accessible archives.
The most common FDA 483 observations related to data integrity involve: missing audit trails on electronic systems, inadequate correction practices, and failure to retain original data.