Central Lab vs Local Lab: What Changes Regulatorily

At a glance

• The usual comparison is turnaround time, cost and standardisation. Those are real and they are not the regulatory question.
• Central laboratory results arrive as external-source data the investigator still owes timely review on. Local results are site source data.
• The evidence you must hold is the same either way: certification, accreditation or validation documentation confirming the tests are suitable, plus documentation of sample collection, processing and shipment.
• The sponsor’s selection test is fit for purpose, which is a judgement about the test in this trial rather than about the vendor in general.
• Neither model is preferred by the regulations. What differs is where the obligations land and where integrity can break.

The comparison that gets written, and the one that matters

Search for central versus local laboratory and you will find turnaround time, cost per sample, kit logistics, assay standardisation across sites, and the operational argument that a central lab removes inter-laboratory variability. All of that is true and worth knowing.

None of it tells you what changes about your obligations.

The two models place trial data in different regulatory positions, and that changes who has to review what, when they can do it, and where the data can lose its integrity in transit. That is the comparison this page makes.

Central lab results are external-source data

ICH E6(R3) names central laboratory data specifically, and it does so inside an obligation on the investigator rather than on the sponsor.

The investigator should be provided with timely access to data by the sponsor and be responsible for the timely review of data, including relevant data from external sources that can have an impact on, for example, participant eligibility, treatment or safety, such as central laboratory data, centrally read imaging data and other institutions’ records (ICH E6(R3) §2.12.3).

Two things follow, and they pull in opposite directions.

The review obligation does not move. An investigator is responsible for reviewing central lab results that bear on eligibility, treatment or safety, exactly as they would be for results generated down the corridor. Outsourcing the assay does not outsource the review.

The investigator no longer controls the timing. They can only review what they have been given, which is why the same sentence puts an obligation on the sponsor to provide timely access. In a central model those two obligations are coupled: a sponsor whose data flow delivers results to the site late has not merely created an operational annoyance, it has made the site’s own obligation impossible to meet.

The practical version for a central-lab trial is a question worth asking at setup rather than at the first safety signal: how does a clinically significant result reach the investigator, how fast, and what happens if the EDC feed is the only route and it is delayed.

Local lab results are site source data

The local model inverts the data position. Results are generated at the site, in the site’s own system or on paper, and they are source data in the ordinary sense. The investigator has them immediately and reviews them as part of normal clinical practice.

What the site gains in immediacy it takes on in record-keeping. The source record is the site’s, which means source data verification happens against the site’s laboratory records, and the site has to be able to produce them for the retention period like any other essential record.

It also means variability between sites is real and uncontrolled, which is the operational argument for central labs and is a scientific concern rather than a compliance one. The regulations do not prohibit it.

The evidence both models require

This is the part most often assumed to be the laboratory’s problem, and it is not. It sits in the essential records regardless of which model you choose.

For laboratory and technical procedures and tests included in the protocol, the essential records include certification or accreditation, or other documentation including of validation where required, to confirm the suitability of the medical, laboratory and technical procedures and tests used during trial conduct, together with documentation of collection, processing and shipment of body fluids and tissue samples (ICH E6(R3), Annex 1 essential records).

Read that against a local-lab trial and the implication is uncomfortable but clear. Choosing the hospital laboratory down the hall does not remove the need to hold evidence that its tests are suitable for this trial. Many sites can produce accreditation readily; the failure mode is nobody asking until an inspection does.

The sample chain documentation is the second half and applies most obviously to central models, where specimens travel. Collection, processing and shipment all have to be documented, which makes the courier and the kit part of the regulatory record rather than pure logistics.

Fit for purpose is the actual selection test

The sponsor’s standing obligations name the criterion directly, and it is narrower than “is this a good laboratory”.

The sponsor documents that laboratory activities and other tests used in the trial are fit for purpose, and documents that service providers are suitably qualified for conducting their delegated or transferred activities (ICH E6(R3), Annex 1 essential records).

Fit for purpose is a judgement about this test, in this trial, for this endpoint. A laboratory can be excellent, accredited and entirely unsuitable for a particular assay at a particular sensitivity. The question is not whether the vendor is reputable but whether the specific tests will produce data that supports the specific conclusions the trial needs.

That is also why vendor selection criteria copied between trials tend to disappoint. The general criteria transfer; the fit-for-purpose judgement does not.

The second clause is the general service-provider duty, which applies to laboratories as it does to any other provider. The wider mechanics of that, meaning allocation, agreements, scope change and acting on noncompliance, belong with vendor oversight generally and are covered separately.

Where integrity breaks in the central model

The central model introduces a data journey that the local model does not have, and journeys are where integrity is lost.

FDA’s guidance on electronic source data lists automated laboratory reporting among the originators of clinical investigation data, alongside investigators and delegated staff, participants, consulting services such as a radiologist reporting on a scan, medical devices, and electronic health records (FDA, Electronic Source Data in Clinical Investigations, 2013). A central laboratory is not a supplier handing over numbers; it is an originator of trial data, and its output carries provenance obligations from the moment it is generated.

The same guidance sets the durability test: data element identifiers should allow sponsors, FDA and other authorised parties to examine the audit trail of the eCRF data, and that audit trail should be readily available in human readable form (FDA, Electronic Source Data in Clinical Investigations, 2013). Human readable is the operative phrase. An audit trail that exists only inside the laboratory’s proprietary system, in a format nobody outside it can interpret, does not satisfy it.

Between the laboratory system and the EDC there is a transfer, and transfers are a stage of the data life cycle with their own requirements. The detail belongs with data integrity generally; the point here is that choosing a central model adds a transfer that a local model does not have, and the metadata has to survive it along with the values.

The handover the site actually feels

Both models create a point where responsibility passes between parties, and the two points are in different places.

In a local model the handover is internal. The site generates the result, holds the source, and reviews it. Where the work is delegated within the site, the investigator should ensure that persons to whom trial-related activities are delegated are appropriately qualified and adequately informed about relevant aspects of the protocol and their assigned activities (ICH E6(R3) §2.3.2), and a record of that delegation should be maintained (ICH E6(R3) §2.3.3). A hospital laboratory running protocol tests is performing trial-related activity, and the delegation question applies to it.

In a central model the handover is external and earlier: it happens at the sample, not at the result. From that moment the sponsor is relying on a service provider, and the general rule applies that activities not specifically transferred to and assumed by a service provider are retained by the sponsor (ICH E6(R3) §3.6.4). What the laboratory contract does not name, the sponsor still owns.

That is worth reading against the sample chain documentation above. Collection happens at the site, processing and shipment may involve a courier and a kit provider, and analysis happens at the lab. Three parties, one obligation to document the chain, and a contract that frequently names only the third.

What the regulations do not decide

Worth stating plainly, because the vendor literature implies otherwise in both directions.

The corpus expresses no preference between central and local laboratories. It sets no threshold for when a trial must centralise, no rule about acceptable inter-site variability, and no requirement that a particular assay be run in a particular place. Those are scientific and operational judgements, and they belong to the protocol and to the people designing it.

What the regulations do is attach obligations to whichever choice you make: timely access and timely review for external-source results, suitability evidence for the tests themselves either way, sample chain documentation where samples travel, and provenance that survives the data’s journey.

Choose on science and operations. Then work out which of those obligations your choice has just handed you, and to whom.

Sources

• ICH E6(R3) Good Clinical Practice, version R3
• FDA Guidance for Industry: Electronic Source Data in Clinical Investigations (2013)