Key messages
Large, well-designed studies of mobile health (mhealth) technologies are needed to measure the distance a person with intermittent claudication can walk pain-free and the maximum distance they can walk.
What is the condition?
In peripheral arterial disease (PAD), the large blood vessels of the legs are narrowed or blocked, which makes it more difficult for oxygen from the blood to get to the muscles when needed. PAD may have no symptoms or may cause a muscle pain called intermittent claudication (IC), which usually affects the legs when a person is walking, and stops when they stop. In some cases, the pain is so severe that it prevents people from walking.
Conditions that make a person more likely to get PAD and IC include high blood pressure, high blood sugar, high cholesterol, obesity, and being a smoker. Claudication can lead to serious cardiac (heart) and circulatory (blood flow) problems, so preventive approaches to address the associated risks usually form the basis of treatment. This helps avoid potential complications such as leg ulcers or gangrene, which can occasionally lead to the need for amputation.
How is the condition treated?
1. Preventive measures, such as regular exercise, maintaining a healthy weight, eating a healthy diet, avoiding tobacco, and reducing anxiety and stress, may help limit how frequently people experience IC and reduce the severity of the pain.
2. Exercise therapy is an important part of managing IC; supervised walking exercise improves walking ability and quality of life. Despite this, only a small percentage of patients exercise on a regular basis.
3. Drugs are frequently used to treat IC. These medications typically help improve circulation or prevent serious problems caused by claudication.
4. Surgical procedures, such as revascularisation interventions (ways of clearing, opening or bypassing blood vessels), can help to restore normal blood flow. This may relieve or reduce the pain from IC.
What did we want to find out?
At a time when technologies are rapidly developing and smartphones and tablets are widely used, mobile-based health technology is a new way to encourage people to walk. Mobile health (mhealth) technologies include wireless devices and sensors that can transmit over the Internet or computer networks, such as mobile phones, smartphones, tablets, short messaging services (SMS) or text messaging, specialised software applications, and wearable technology. We wanted to find out whether mhealth technologies can increase the distance that people with IC are able to walk.
What did we do?
We searched for studies that compared mhealth technologies versus usual care (no intervention or no advice to exercise), exercise advice, or a supervised exercise programme in people with IC. We compared and summarised the studies' results, and rated our confidence in the evidence, based on factors such as study methods and sizes.
What did we find?
We found four studies that involved 614 people with IC who had an average age of 68 years. The studies were conducted in the USA. Two studies lasted for three months, one for nine months, and one for 12 months.
Our analysis showed there is no clear effect of mhealth technologies on the maximum distance that people can walk.
We do not know if there is a difference in pain-free walking distance because none of the studies reported on it. None of the studies reported on change in the time people survived without an amputation ('amputation-free survival') or a procedure to improve their circulation ('revascularisation-free survival'). Only one study reported on major adverse cardiovascular events (defined as stroke, myocardial infarction (heart attack) or cardiac-related death events) and found no clear difference between groups. None of the included studies reported on major adverse limb events (defined as severe limb ischaemia (sudden and significant reduction of blood flow to the limb) leading to an intervention or major amputation) or above-ankle amputations.
What are the limitations of the evidence?
Our confidence in the evidence is low because the studies tested a small number of people overall, and people taking part would have known which intervention they had received, which could have affected how they complied with the exercise programme. Not all the studies provided information about everything that we were interested in.
How up-to-date is this evidence?
The evidence is up‐to‐date to 19 December 2022.
Mobile health technologies can be used to provide lifestyle interventions for people with chronic conditions, such as IC. We identified a limited number of studies that met our inclusion criteria. We found no clear difference between mhealth and usual care in improving absolute walking distance in people with IC; however, we judged the evidence to be low certainty. Larger, well-designed RCTs are needed to provide adequate statistical power to reliably evaluate the effects of mhealth technologies on walking distance in people with IC.
Peripheral arterial disease (PAD) is the obstruction or narrowing of the large arteries of the lower limbs, which can result in impaired oxygen supply to the muscle and other tissues during exercise, or even at rest in more severe cases. PAD is classified into five categories (Fontaine classification). It may be asymptomatic or various levels of claudication pain may be present; at a later stage, there may be ulceration or gangrene of the limb, with amputation occasionally being required. About 20% of people with PAD suffer from intermittent claudication (IC), which is muscular discomfort in the lower extremities induced by exertion and relieved by rest within 10 minutes; IC causes restriction of movement in daily life.
Treatment for people with IC involves addressing lifestyle risk factors. Exercise is an important part of treatment, but supervised exercise programmes for individuals with IC have low engagement levels and high attrition rates. The use of mobile technologies has been suggested as a new way to engage people with IC in walking exercise interventions. The novelty of the intervention, low cost for the user, automation, and ease of access are some of the advantages mobile health (mhealth) technologies provide that give them the potential to be effective in boosting physical activity in adults.
To assess the benefits and harms of mobile health (mhealth) technologies to improve walking distance in people with intermittent claudication.
The Cochrane Vascular Information Specialist conducted systematic searches of the Cochrane Vascular Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and CINAHL, and also searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov. The most recent searches were carried out on 19 December 2022.
We included randomised controlled trials (RCTs) in people aged 18 years or over with symptomatic PAD and a clinical diagnosis of IC. We included RCTs comparing mhealth interventions to improve walking distance versus usual care (no intervention or non-exercise advice), exercise advice, or supervised exercise programmes. We excluded people with chronic limb-threatening ischaemia (Fontaine III and IV).
We used standard Cochrane methods. Our primary outcomes were change in absolute walking distance from baseline, change in claudication distance from baseline, amputation-free survival, revascularisation-free survival. Our secondary outcomes were major adverse cardiovascular events, major adverse limb events, above-ankle amputation, quality of life, and adverse events. We used GRADE to assess the certainty of the evidence.
We included four RCTs involving a total of 614 participants with a clinical diagnosis of IC. The duration of intervention of the four included RCTs ranged from 3 to 12 months. Participants were randomised to either mhealth or control (usual care or supervised exercise programme). All four studies had an unclear or high risk of bias in one or several domains. The most prevalent risk of bias was in the area of performance bias, which was rated high risk as it is not possible to blind participants and personnel in this type of trial. Based on GRADE criteria, we downgraded the certainty of the evidence to low, due to concerns about risk of bias, imprecision, and clinical inconsistency.
Comparing mhealth with usual care, there was no clear evidence of an effect on absolute walking distance (mean difference 9.99 metres, 95% confidence interval (CI) -27.96 to 47.93; 2 studies, 503 participants; low-certainty evidence). None of the included studies reported on change in claudication walking distance, amputation-free survival, or revascularisation-free survival.
Only one study reported on major adverse cardiovascular events (MACE) and found no clear difference between groups (risk ratio 1.37, 95% CI 0.07 to 28.17; 1 study, 305 participants; low-certainty evidence). None of the included studies reported on major adverse limb events (MALE) or above-ankle amputations.