Chain of Custody in Diagnostic Sample Collection

Why it matters beyond compliance

The obvious reason to maintain custody records is accountability. The more useful reason is diagnosis of your own operation. When a sample is rejected for haemolysis, a custody trail tells you whether it spent ninety minutes in a car boot or twelve minutes in a conditioned carrier. Without that trail, every rejection is attributed to whoever is easiest to blame, and nothing improves.

The second practical benefit is patient trust. A patient who is told exactly when their sample was collected, when it moved and when the laboratory received it is a patient who does not need reassurance calls.

The events worth recording

A workable custody record captures these events, each with time and identity:

1. Collection request created, with patient and requisition reference
2. Collector assigned
3. Patient identity confirmed at the point of collection
4. Specimen collected and labelled, with collection time
5. Specimen packed, with containment and temperature category
6. Movement started toward the laboratory or handover point
7. Custody transferred — handing party, receiving party, time and place
8. Laboratory receipt, with condition assessment
9. Rejection or acceptance, with reason code where rejected

Nine events. Fewer than that and gaps appear; many more and collectors stop recording accurately, which is worse than not recording at all.

Where custody breaks in home collection

The recurring failure modes are predictable, which makes them preventable:

• Tubes labelled away from the patient, at the vehicle or the hub
• Verbal handovers between collector and runner with no record
• One collector carrying another collector's samples informally
• Samples left at a reception desk or with a security guard
• Manifests completed retrospectively at the end of a shift
• Paper records that exist but cannot be retrieved when questioned
• Reassignment mid-route with no note of who holds what

Labelling is the foundation

Custody begins with identity. A specimen whose identity depends on someone's recollection has no custody chain, however well the subsequent transfers are documented.

The rule is unambiguous: tubes are labelled at the point of collection, in the patient's presence, and checked against the requisition before the collector leaves. Everything downstream depends on this being non-negotiable.

Digital custody, and why it changes behaviour

Paper manifests work when volume is low and storage is disciplined. They fail at scale, and they fail retrospectively — you discover the gap when you need the record.

Digital capture attaches each custody event to the request as it happens, with a timestamp nobody has to remember. Phlebify records collection and handover events digitally, including QR-enabled steps in the workflow, so the trail is available while the sample is still moving rather than reconstructed afterwards. See digital collection tracking.

There is a behavioural effect worth naming: transfers that must be recorded tend to happen promptly and in the right place. Custody discipline improves punctuality as a side effect.

Paper versus digital custody

Custody and recollections

Recollection decisions depend on custody data. If a sample arrives haemolysed and the record shows a two-hour ambient hold, the corrective action is a routing change, and the recollection is the operation's cost to own. If the record shows a clean twenty-minute journey, the issue is more likely the draw technique, and the corrective action is training.

Without the trail, both cases produce the same outcome — an argument and a repeat visit for the patient. Recollection handling develops this further.

How Phlebify approaches custody

Every collection Phlebify coordinates carries a request-level trail: assignment, collection, packing, movement and handover. Partner laboratories can see that trail rather than requesting it.

For the wider workflow, see the diagnostic logistics platform and home sample collection.