Intermittent ClaudicationNCT04370327
The Effects of Claudication Severity on Functional Outcomes
A study testing Pain Free Exercise (PF), Moderate Claudication Pain Exercise (MOD-P) and Maximal Claudication Pain Exercise (MAX-P) in people with Intermittent Claudication, run by University of Central Lancashire at 1 site in United Kingdom.
Trial summary
Peripheral artery disease (PAD) affects over 236 million people globally. A classic symptom of PAD is intermittent claudication (IC) which is associated with reductions in physical function. The evidence is irrefutable that supervised exercise programmes (SEP) improve pain free and maximal waking distance. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Intermittent Claudication
- What is being tested?
- Pain Free Exercise (PF), Moderate Claudication Pain Exercise (MOD-P) and Maximal Claudication Pain Exercise (MAX-P)
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 57 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 5 Jul 2021to 13 Oct 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- >18 years old
- Resting ankle brachial pressure index (ABPI) <90 mmHg
- Able to walk unaided
- English speaking and able to follow exercise instructions
- Able to provide informed consent
Who cannot join
- Those who have critical limb threatening ischaemia (rest pain and/or tissue loss)
- Unable to provide consent
- Those undergoing active cancer treatment
- Those presenting with any significant comorbidities or contraindications to exercise testing or training in accordance to the American College of Sports Medicine
- Unstable/uncontrolled coronary heart disease
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Effects of Claudication Severity on Functional Outcomes in Patients With Intermittent Claudication
Peripheral artery disease (PAD) affects over 236 million people globally. A classic symptom of PAD is intermittent claudication (IC) which is associated with reductions in physical function. The evidence is irrefutable that supervised exercise programmes (SEP) improve pain free and maximal waking distance. However, adherence rates are poor with exercise-related pain cited as contributable factor. Exercise at mild claudication or pain- free exercise improves walking ability, however current guidelines recommend exercise should be performed to near maximal claudication to improve walking ability. Conflicting evidence exists and there is a lack of evidence that has directly compared the relative effects of exercise prescribed at different levels of claudication. Therefore, the primary objective is to directly compare the effects of exercise prescribed at different levels of claudication pain on functional outcomes
Read the detailed description
Peripheral artery disease (PAD) is a progressive disease and is characterised by atherosclerotic occlusion of the arteries in the lower limbs, resulting in a reduction of blow flow. Globally, it is estimated that 236 million people are living with PAD, with the number of cases increasing by 24% from 2000 to 2010 (Song et al., 2019). A classic symptom of PAD is intermittent claudication (IC), which is characterised by ischemic muscle pain precipitated by exertion and relieved by rest. IC is associated with various comorbidities such as diabetes mellitus, hypertension and dyslipidaemia as well as reductions in physical function, quality of life, and balance. National and international guidelines recommend exercise therapy as first line treatment for patients with IC, advocating two hours per week of a supervised exercise over a three-month period, with patients being encouraged to exercise to the point of maximal pain. Exercise therapy is also a cost-effective option, as a three month programme costs less than a tenth of the cost of angioplasty.
However, despite the plethora of evidence demonstrating the benefits of SEP, less than half of vascular units in the United Kingdom (UK) have access one and patient uptake rates low. A lack of motivation has been shown as one of the primary reasons for poor adherence with claudication pain being suggested as a contributable factor. Indeed, exercise-induced pain has been shown as a major barrier to physical activity in this population and the level of pain prescribed during SEP influences completion rates. When exercise is prescribed at higher levels of pain, completion rates are lower. However, current evidence and guidelines advocate exercising to the point of near maximal pain, despite evidence to the contrary, suggesting that mild- or pain-free exercise improves walking ability. As such, it remains unclear which level of claudication is optimal for improving functional outcomes in patients with IC which can affect patient adherence, clinical practice and exercise prescription. The lack of adequately powered, randomised clinical trials investigating the effects of exercise prescribed at differing levels of claudication pain has also been highlighted in a recent scientific statement from the American Heart Association
- Conditions
- Intermittent Claudication
- Being tested
- Pain Free Exercise (PF), Moderate Claudication Pain Exercise (MOD-P), Maximal Claudication Pain Exercise (MAX-P)
- Medical subject headings
- Intermittent Claudication
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Pain Free Exercise (PF)Other
Patients will exercise until the onset on claudication (1 on the rating scale)
Moderate Claudication Pain Exercise (MOD-P)Other
Patients will exercise until they experience moderate claudication pain (2 on the rating scale)
Maximal Claudication Pain Exercise (MAX-P)Other
Patients will exercise until they experience maximal claudication pain (4 on the rating scale)
| Study group | Role | What they receive |
|---|---|---|
| Pain Free Exercise (PF) | Active comparator | Patients will be randomised to twice weekly for 12 and 24 weeks (site specific) of pain free exercise in a supervised exercise programme Receives: Other: Pain Free Exercise (PF) |
| Moderate Claudication Pain Exercise (MOD-P) | Active comparator | Patients will be randomised to twice weekly for 12 and 24 weeks (site specific) of moderate claudication pain exercise in a supervised exercise programme Receives: Other: Moderate Claudication Pain Exercise (MOD-P) |
| Maximal Claudication Pain Exercise (MAX-P) | Active comparator | Patients will be randomised to twice weekly for 12 and 24 weeks (site specific) of maximal claudication pain exercise in a supervised exercise programme Receives: Other: Maximal Claudication Pain Exercise (MAX-P) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Maximal Walking Distance (MWD)
Metres walked until maximal claudication pain
Measured: 12 and 24 weeks (site specific)
Secondary outcomes (3)
Change in Pain Free Walking Distance (PFWD)
Metres walked pain free
Measured: 12 and 24 weeks (site specific)
Adherence
Recording the number of training sessions attended and successfully completed
Measured: 24 weeks
Change in Quality of Life
King College 24-item Vascular Quality of life and walking impairment questionnaire
Measured: 12 and 24 weeks (site specific)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Apr 2020
- Study start5 Jul 2021
- Primary completion16 Jun 2026
- Study completion13 Oct 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Intermittent ClaudicationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 57 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Central Lancashire
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Stefan Birkett, Manchester Metropolitan University
- Investigators
- Stefan Birkett, PHD, Principal investigator, Manchester Metropolitan University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04370327
- Sponsor's protocol ID
- UCentalLancashirePAD
- Status last verified
- Oct 2026
- First submitted
- 23 Apr 2020
- Last updated
- 20 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Birkett ST, Sinclair J, Seed SA, Pymer S, Caldow E, Ingle L, Harwood AE, Egun A. Effects of exercise prescribed at different levels of claudication pain on walking performance in patients with intermittent claudication: a protocol for a randomised controlled trial. Ther Adv Cardiovasc Dis. 2022 Jan-Dec;16:17539447221108817. doi: 10.1177/17539447221108817.
PubMed 35762773
Study at a glance
From the registry record, last updated by the sponsor on 20 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of Claudication Severity on Functional Outcomes in Patients With Intermittent Claudication
- ClinicalTrials.gov ID
- NCT04370327
- Acronym / sponsor ID
- UCentalLancashirePAD
- Conditions
- Intermittent Claudication
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 57 participants (actual)
- Lead sponsor
- University of Central LancashireUniversity, hospital or other
- Study start
- 5 Jul 2021 (actual)
- Primary completion
- 16 Jun 2026 (actual)
- Study completion
- 13 Oct 2026 (actual)
- First posted
- 30 Apr 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Peripheral artery disease (PAD) affects over 236 million people globally. A classic symptom of PAD is intermittent claudication (IC) which is associated with reductions in physical function. The evidence is irrefutable that supervised exercise programmes (SEP) improve pain free and maximal waking distance. However, adherence rates are poor with exercise-related pain cited as contributable factor. Exercise at mild claudication or pain- free exercise improves walking ability, however current guidelines recommend exercise should be performed to near maximal claudication to improve walking ability. Conflicting evidence exists and there is a lack of evidence that has directly compared the relative effects of exercise prescribed at different levels of claudication. Therefore, the primary objective is to directly compare the effects of exercise prescribed at different levels of claudication pain on functional outcomes
Detailed description
Peripheral artery disease (PAD) is a progressive disease and is characterised by atherosclerotic occlusion of the arteries in the lower limbs, resulting in a reduction of blow flow. Globally, it is estimated that 236 million people are living with PAD, with the number of cases increasing by 24% from 2000 to 2010 (Song et al., 2019). A classic symptom of PAD is intermittent claudication (IC), which is characterised by ischemic muscle pain precipitated by exertion and relieved by rest. IC is associated with various comorbidities such as diabetes mellitus, hypertension and dyslipidaemia as well as reductions in physical function, quality of life, and balance. National and international guidelines recommend exercise therapy as first line treatment for patients with IC, advocating two hours per week of a supervised exercise over a three-month period, with patients being encouraged to exercise to the point of maximal pain. Exercise therapy is also a cost-effective option, as a three month programme costs less than a tenth of the cost of angioplasty.
However, despite the plethora of evidence demonstrating the benefits of SEP, less than half of vascular units in the United Kingdom (UK) have access one and patient uptake rates low. A lack of motivation has been shown as one of the primary reasons for poor adherence with claudication pain being suggested as a contributable factor. Indeed, exercise-induced pain has been shown as a major barrier to physical activity in this population and the level of pain prescribed during SEP influences completion rates. When exercise is prescribed at higher levels of pain, completion rates are lower. However, current evidence and guidelines advocate exercising to the point of near maximal pain, despite evidence to the contrary, suggesting that mild- or pain-free exercise improves walking ability. As such, it remains unclear which level of claudication is optimal for improving functional outcomes in patients with IC which can affect patient adherence, clinical practice and exercise prescription. The lack of adequately powered, randomised clinical trials investigating the effects of exercise prescribed at differing levels of claudication pain has also been highlighted in a recent scientific statement from the American Heart Association
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Pain Free Exercise (PF) | Active comparator | Other: Pain Free Exercise (PF)Patients will be randomised to twice weekly for 12 and 24 weeks (site specific) of pain free exercise in a supervised exercise programme |
| Moderate Claudication Pain Exercise (MOD-P) | Active comparator | Other: Moderate Claudication Pain Exercise (MOD-P)Patients will be randomised to twice weekly for 12 and 24 weeks (site specific) of moderate claudication pain exercise in a supervised exercise programme |
| Maximal Claudication Pain Exercise (MAX-P) | Active comparator | Other: Maximal Claudication Pain Exercise (MAX-P)Patients will be randomised to twice weekly for 12 and 24 weeks (site specific) of maximal claudication pain exercise in a supervised exercise programme |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- >18 years old
- Resting ankle brachial pressure index (ABPI) <90 mmHg
- Able to walk unaided
- English speaking and able to follow exercise instructions
- Able to provide informed consent
Key exclusion criteria (5 listed)
- Those who have critical limb threatening ischaemia (rest pain and/or tissue loss)
- Unable to provide consent
- Those undergoing active cancer treatment
- Those presenting with any significant comorbidities or contraindications to exercise testing or training in accordance to the American College of Sports Medicine
- Unstable/uncontrolled coronary heart disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Pain Free Exercise (PF)Patients will exercise until the onset on claudication (1 on the rating scale) | Other | Pain Free Exercise (PF) |
| Moderate Claudication Pain Exercise (MOD-P)Patients will exercise until they experience moderate claudication pain (2 on the rating scale) | Other | Moderate Claudication Pain Exercise (MOD-P) |
| Maximal Claudication Pain Exercise (MAX-P)Patients will exercise until they experience maximal claudication pain (4 on the rating scale) | Other | Maximal Claudication Pain Exercise (MAX-P) |
Primary outcome
Change in Maximal Walking Distance (MWD)
Time frame: 12 and 24 weeks (site specific)
Metres walked until maximal claudication pain
3 secondary outcomes
Change in Pain Free Walking Distance (PFWD)
Time frame: 12 and 24 weeks (site specific)
Adherence
Time frame: 24 weeks
Change in Quality of Life
Time frame: 12 and 24 weeks (site specific)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Oct 2026.
- Derived from this study: PubMed 35762773Birkett ST, Sinclair J, Seed SA, Pymer S, Caldow E, Ingle L, Harwood AE, Egun A. Effects of exercise prescribed at different levels of claudication pain on walking performance in patients with intermittent claudication: a protocol for a randomised controlled trial. Ther Adv Cardiovasc Dis. 2022 Jan-Dec;16:17539447221108817. doi: 10.1177/17539447221108817.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Stefan Birkett, PHD principal investigator
Manchester Metropolitan University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Pain Free Exercise (PF), Moderate Claudication Pain Exercise (MOD-P) and Maximal Claudication Pain Exercise (MAX-P) in people with Intermittent Claudication, run by University of Central Lancashire at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 20 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Maximal Walking Distance (MWD) (time frame: 12 and 24 weeks (site specific)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04370327, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Oct 2026.