What Are Decentralised Clinical Trials? Methods, Risks and UK Rules

Decentralised clinical trials run trial activity at locations other than the investigator site. The Health Research Authority (HRA) and the Medicines and Healthcare products Regulatory Agency (MHRA) define decentralised trial methods as trial-related activities that occur at locations other than clinical trial investigator sites. That covers a participant’s home, a local healthcare facility, and any activity conducted digitally.

A decentralised trial changes where the work happens. It leaves the sponsor, the protocol, the investigator and the regulatory obligations exactly where they were. Every assessment performed at a distance still requires a named delegate, a source record with a known location, and an audit trail an inspector can follow back to the site file.

The visit moves. The accountability does not.

This guide sets out the seven methods that make a trial decentralised, the three artefacts where decentralised delivery breaks down in practice, what the amended UK Clinical Trials Regulations have required since 28 April 2026, and the questions a study team should settle before it adds a single remote element. (FDA and ICH documents use the spelling decentralized for the same set of methods.)

What Counts as a Decentralised Trial Method?

A trial becomes decentralised one method at a time. Most UK studies adopt two or three elements rather than a fully remote design, and each element carries its own delegation, consent and record-keeping consequences. The table below lists the seven methods used most often in UK studies, the location each one moves work to, and the record each one has to produce.

Each row moves one activity out of the building. None of them moves the investigator’s responsibility for it. A study running four of these methods has four separate evidence chains to maintain, and the clinical trial management system is where those chains either meet or fail to.

Where Do Decentralised Trials Fail?

Decentralised trials fail at the joins. The individual methods are well understood, and the risk sits in the paperwork that connects an off-site activity back to the study record. Three artefacts carry most of it: the delegation log, the IMP accountability record, and the source data location list.

A hypothetical example makes the pattern concrete. A phase III study at an NHS trust adds home nursing visits in month four to recover recruitment. The provider’s nurses draw bloods and record vital signs in participants’ homes. The trust adds the provider to the contract, briefs the nurses and starts the visits. An MHRA inspector arrives six months later and asks one question: which named individual was delegated to perform vital signs on 14 March, and where is the evidence of their GCP training on that date? The delegation log names the provider as an organisation. It names no individuals. The visits were performed correctly. The record cannot demonstrate it.

The work was performed. The evidence that an authorised person performed it was never created.

The same gap opens in six more places, each one a join between an off-site activity and the study record:

• Provider staff appear on a contract and never reach the delegation log, which leaves the investigator unable to evidence authorisation for any single visit.
• The source data location list stops matching reality once a value first exists on a participant’s device or in a provider’s system, which sends monitors to the wrong place and leaves the true source unverified.
• IMP shipped directly to a participant leaves the accountability chain open where receipt, storage temperature and return sit in a courier system the trial pharmacy cannot reconcile against its own pharmacy site file.
• Consent versions drift where an eConsent platform pushes an amended participant information sheet on a different date from the site’s own approval record.
• Visit windows calculated from a site diary drift from actual contact dates once visits happen at the participant’s convenience.
• Provider staff training sits in the provider’s own system, which leaves the site file without the training evidence for people acting on the study.

What Do the UK Rules Require Since April 2026?

UK clinical trials operate under an amended framework. The Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 (SI 2025/538) came into force on 28 April 2026, and ICH-GCP E6(R3) came into force in the UK alongside them. Neither instrument creates a separate regime for decentralised trials. Both apply the same duties to a trial run at a distance.

The HRA and MHRA state that they support and encourage remote trial delivery where it is safe and appropriate. Their decentralised trial methods position statement, last updated on 28 April 2026, sets out five expectations of the sponsor. Two are framed as obligations and three as expectations, and the difference matters when a sponsor writes its own risk documentation:

• Must: sponsors assess, verify and validate the technology, methodology and usability of any novel digital or other end-points that will be used to collect data directly from participants. Device and platform validation therefore sits inside the sponsor’s own quality system, dated before the first participant uses it.
• Must: sponsors do ongoing risk assessment to ensure that decentralised trial methods maximise the benefit to participants, without compromising participant safety and trial oversight. The assessment runs for the life of the trial.
• Should: sponsors consider factors such as disease, developmental stage of the treatment, administration of the treatment, trial population and the reliability of assessments when they judge which methods suit a study.
• Should: sponsors consult relevant investigators to address the implications for investigator sites, and to ensure that the trial design allows for appropriate investigator oversight.
• Should: sponsors involve people with relevant experience, including patients, family members and carers, in the design of trials.

Two further points govern day-to-day delivery. ICH-GCP E6(R3) carries the computerised-system expectations that decentralised methods depend on, covering audit trails, metadata, traceability and system validation. Electronic methods may be used for seeking, confirming and documenting informed consent under the joint HRA and MHRA statement on eConsent, which allows an electronic process to supplement or replace the paper one.

The transitional arrangements split studies by submission date. A trial whose application was submitted before 28 April 2026 is an old rules clinical trial, even where the outcome arrived after that date. A trial submitted on or after it is a new rules clinical trial. A study adding decentralised methods mid-course should confirm which set applies before it changes anything.

Also Read: NHS Clinical Research Software and ICH-GCP E6(R3): What the New UK CTR Requires

How Does a Decentralised Trial Change Site Operations?

The operational difference is a change in the number of parties holding a piece of one study. A site-centric trial keeps activity, supervision and records inside one building. A trial with decentralised methods spreads all three across several organisations while the investigator’s duty stays whole.

Three practical consequences follow for the site team. The first is contractual. Every provider performing a trial activity needs an agreement that names the study, sets the standard of work and settles access to the records it creates. A generic service contract rarely covers any of the three.

The second is the source data location list. A site-centric study can treat the medical record and the site file as the answer to where a value lives. A decentralised study has to say, for each data point, which system holds the first recorded instance of it, and whether that system is the participant’s device, the provider’s record, the laboratory’s report or the site’s own note. Monitors work from that list, and an inspector reads it as a statement of control.

The third is training and oversight. Provider staff performing trial activities sit inside the investigator’s oversight in the same way site staff do. The site needs their training evidence, their delegation entry and a record of how their work was overseen, filed where the study can produce it on request.

The right-hand column describes more organisations, more systems and more record types for the same protocol. Study teams that route each record to a single owning system keep the picture legible, and the boundaries between a CTMS, an eTMF, an EDC system and an eISF decide where each piece of decentralised evidence belongs.

Which Benefits Hold Up in Practice?

Decentralised methods earn their place where they remove a specific barrier for a specific population. The broad claims made for them are harder to defend than the mechanisms behind them, so the useful test is what each method changes in operational terms.

• Electronic consent lets a participant read and sign at home across several sessions. The screening step loses a travel journey and the participant gains time to consider.
• Home nursing visits move a routine assessment to the participant, which widens the eligible population to people who cannot travel to a site on a weekday.
• Local sample collection uses a facility near the participant. Studies with frequent bloods draw on a wider geographic pool for patient recruitment.
• ePRO captures a symptom at the moment it occurs, which reduces the recall effect of a diary completed in a waiting room.
• A remote monitoring model gives the sponsor a continuous view of data as it arrives. A query can reach the site within days, ahead of the next monitoring visit.
• Direct-to-participant IMP supply removes a collection journey, which supports retention on studies with long dosing periods.

Each mechanism carries a cost. A home visit needs a delegated, trained and monitored individual. A remote endpoint needs validation evidence dated before the first participant uses it. The saving in participant burden shows up later, in recruitment and retention. The cost lands earlier, in study set-up. Set-up is the segment UK studies already lose time in, measured against the national clinical research delivery indicators and the 90-day set-up target.

Also Read: Clinical Trial Site Selection: Best Practices for UK Studies

Which Risks Need Controlling Before Recruitment Opens?

Decentralised delivery carries governance risk. Each risk below has a control that has to exist before the method goes live, and every one of them is cheaper to build at set-up than to reconstruct for an inspector.

The last row is where NHS studies spend the most unplanned time. Every additional supplier holding participant data brings its own assurance pack, and the DSPT and Cyber Essentials evidence NHS procurement expects applies to each of them separately.

What Should a Team Settle Before Adding a Decentralised Element?

Eight questions decide whether a decentralised element is ready. They apply to each element separately, so a study adding home visits and ePRO answers them twice. Answer them for one element before you add the next.

1. Which single activity moves, and to which location?
2. Which named individual performs it, and how does the delegation log record them across an organisational boundary?
3. Where does the source record first exist, and which entry on the source data location list points to it?
4. Which system holds the audit trail, and can the site read it without asking the sponsor?
5. What validation evidence exists for the device or platform, and is it dated before first participant use?
6. How does the trial pharmacy reconcile IMP a courier delivered and a participant returned?
7. Who trains provider staff, and where does that training appear in the investigator site file?
8. Which approvals does the change need, and does the study run under the old rules or the new rules?

A team with answers to all eight for one element is ready to add that element. A team with answers to none of them is scheduling a finding.

How Does AQ Support Decentralised Trial Delivery?

Decentralised delivery pulls one study record into several systems. AQ holds it as one record across the locations a study runs in.

• AQ CTMS tracks visits, windows and participant contact wherever each visit takes place, which keeps one operational picture when work happens in four locations at once.
• AQ Digital DoA records delegation at individual level across organisational boundaries. The investigator can show a named, dated authorisation behind an off-site activity.
• AQ ePSF holds IMP receipt, storage, dispensing, return and destruction as one pharmacy record, which closes the accountability chain where supply goes direct to a participant.
• AQ eISF keeps essential site documents current and available for remote review. The pre-visit search across shared drives and sponsor portals falls away.
• AQ QMS links controlled SOPs and training records to the people delegated to act, which is where a home nursing provider’s staff have to appear.

Book a live demo to see how one study record holds together across every location a decentralised trial runs in.