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A collection date alone may not explain specimen handling in an IVD study. Collection, separation, storage and analysis can occur at different times. Delays outside supported test conditions may affect interpretation; select important timestamps according to the research question.
Define the assessment
Explain the event and clock source represented by each timestamp. Routine laboratory intervals may differ from conditions supported for the investigated assay. Rather than inventing universal storage limits, assess device instructions, available evidence and the study plan together.
Worked example
For example, two sites ship specimens collected on the same day. One separated them immediately, the other the next morning. The central record contains only receipt date. The team investigates missing times, identifies specimens with verifiable conditions and opens an impact assessment. Unknown intervals are not filled with a default value.
Practical checks
- Define collection, important processing and analysis events in the data dictionary.
- Record how clock differences or missing times affect suitability decisions.
- Link acceptance of unplanned delays to authorised review and supporting evidence.
Decision and limitations
The report should describe assessed conditions and the unverified portion. A delay is not automatically invalidating, but should not be dismissed without assessment. Examine effects through suitable technical and clinical review; exclusions should not be chosen arbitrarily after seeing results.
Frequently asked questions
- Is collection date sufficient?
- Not always. Time of day and important processing steps may matter for the test question.
- Must delayed specimens automatically be discarded?
- Assess supported conditions and the study approach, retaining the reasoned decision and record.