The effects of including quality of life responses in models to predict walking performance of patients with intermittent claudication

Maximal calf conductance is associated with 6-minute walk distance in participants with and without peripheral artery disease

INTRODUCTION

The aims were (a) to compare the maximal calf conductance and 6-minute walk distance of participants with and without peripheral artery disease (PAD) and claudication, (b) to determine whether maximal calf conductance was more strongly associated with 6-minute walk distance in participants with PAD than in the controls, and (c) to determine whether this association was significant in participants with PAD after adjusting for ABI, as well as for demographic, anthropometric, and comorbid variables.

METHODS

Participants with PAD (n = 633) and without PAD (n = 327) were assessed on maximal calf conductance using venous occlusion plethysmography, and on 6-minute walk distance. Participants were further characterized on ABI, and on demographic, anthropometric, and comorbid variables.

RESULTS

The PAD group had lower maximal calf conductance than the control group (0.136 ± 0.071 vs 0.201 ± 0.113 mL/100 mL/min/mmHg, p < 0.001). Additionally, the PAD group had a lower 6-minute walk distance (375 ± 98 m vs 480 ± 107 m, p < 0.001). Maximal calf conductance was positively associated with 6-minute walk distance in both groups (p < 0.001) and was more strongly associated in the PAD group (p < 0.001). In adjusted analyses, maximal calf conductance remained positively associated with 6-minute walk distance in the PAD group (p < 0.001) and in the control group (p < 0.001).

CONCLUSIONS

Participants with PAD and claudication had impaired maximal calf conductance and a lower 6-minute walk distance than those without PAD, and maximal calf conductance was positively and independently associated with 6-minute walk distance within each group before and after adjusting for ABI, and for demographic, anthropometric, and comorbid variables.

A systematic review of exercise intervention reporting quality and dose in studies of intermittent claudication

BACKGROUND

Exercise therapy is an important treatment option for people with intermittent claudication (IC). Appropriate reporting of exercise interventions in populations with IC within randomised controlled trials (RCTs) is important to ensure that research can be translated into clinical practice. Therefore, the purpose of our review is to evaluate the reporting of exercise interventions in RCTs of exercise therapy in patients with IC.

METHODS

A systematic search was performed to identify relevant trials in patients with IC published until May 2020. Studies including only participants with critical limb ischaemia or asymptomatic peripheral artery disease were excluded. Each trial was scored using the recently developed 'Consensus on Exercise Reporting Template' (CERT) which has a maximum obtainable score of 19.

RESULTS

Of 1489 unique records identified from the search, 73 trials were included, reporting 107 exercise interventions. Overall, the average CERT score was 10/19. The exercise equipment used, the use of supervision and a description of whether the exercise prescription was tailored or generic were the most frequently reported intervention components. The motivational strategies used, intervention adherence and intervention fidelity were the most underreported CERT components. There was no trend indicating that CERT scores were higher in more recent publications.

CONCLUSIONS

We have identified that important details about exercise interventions are frequently missing from the published literature. These missing data hinder replication of research findings and limit the translation of evidence into clinical practice.

Mobile applications in peripheral arterial disease (PAD): a review and introduction of a new innovative telemonitoring application: JBZetje

Introduction:Peripheral arterial disease (PAD) is an occlusive vascular disease of the lower extremities with increasing incidence and prevalence numbers and therefore rising health care costs. Mobile applications have great potential to improve health system efficiency and can assist in overcoming the increasing health care costs. In this review all available mobile applications developed for PAD are summarized and a new innovative application is introduced.Areas covered:Available applications for PAD are scarce and currently aim at prevention, teleconsultation and telemonitoring via questionnaires and activity tracking. Integration in the daily workflow of the physician is an overlooked aspect of these applications. JBZetje is an innovative mobile application that provides remote care, information services and self-service tools, and enables connection with the electronic health record (EHR).Expert opinion:Connection of the application with the EHR generates a complete overview of a patient's current health status. This will reinforce the tendency toward personalized medicine and will probably lead to reduced health care costs and increase the quality of care. Future feasibility studies should answer the question whether the use of mobile applications is feasible in the PAD population.

Relationship between requirement to stop during a six-minute walk test and health-related quality of life, physical activity and physical performance amongst people with intermittent claudication

AIM

A simple objective test is required to identify people with impaired physical aspects of health-related quality of life (QOL) due to intermittent claudication. This study assessed the relationship of QOL, function and physical activity to the need to stop during a six-minute walking test (6MWT) amongst people with intermittent claudication.

METHOD

This was a prospective case-control study conducted at two centers in Australia. 173 participants with a history of intermittent claudication and peripheral artery disease diagnosed by ankle brachial pressure index <0.9, completed two 6MWTs one week apart. QOL was assessed with the short form (SF)-36. Physical activity was assessed by an accelerometer to record step count, stepping time and energy expenditure over 7 days. Physical performance was assessed by the Short Physical Performance Battery (SPPB) test. The associations of the need to stop at least once during the 6MWT with QOL, function and activity were assessed using Mann Whitney U test and analysis of covariates.

RESULTS

Participants that had to stop at least once during the two 6MWTs (46; 26.6%) had significantly lower scores for three of the domains (physical functioning, role-physical and bodily pain) and the physical component summary (PCS) measure of the SF-36 compared to those who did not need to stop (n = 127; 73.4%). After adjusting for the risk factor co-variates (diabetes, hypertension and ankle brachial pressure index) which were significantly unequally distributed, needing to stop during the 6MWTs was significantly associated with a lower PCS score (adjusted mean 36.5, standard error 0.8 vs. 30.5, standard error 1.3; F = 14.0; P < 0.001; partial eta squared 0.077). Participants that had to stop at least once during the two 6MWTs had significantly lower 7-day step count, time stepping and energy expenditure, but not total SPPB score, compared to those who did not need to stop.

CONCLUSIONS

Needing to stop during a 6MWT identified participants with intermittent claudication with poorer QOL and less physical activity compared to those that do not need to stop.

Assessment of all-cause and cardiovascular death risk in Russian men with leg pain

Aim. To study the prevalence of intermittent claudication (IC) and assess the risk of cardiovascular and all-cause death In Russian men with IC according to 30-year follow-up.

Material and methods. The study used data obtained from representative samples of men examined inMoscow andSt. Petersburg (formerly known  as Leningrad) from 1975 to 1986. Response rate was 75%. The examination of men (n=10953) aged 35-70 years (mean age 48,8±6,6 years) was carried out according to a single protocol, which included a standard survey, biochemical profile test, measurement of blood pressure (BP) and heart rate, anthropometry and 12-lead electrocardiography. To determine IC, the original Rose questionnaire was used, according to which four categories of pain were identified. The first is the absence of pain (P0); the second — mixed pain, including not associated with exercise (P1); the third — atypical pain in calf muscles lasting >10 minutes of rest (P2); the fourth — typical IC (P3). The median follow-up was 21,9 years. In total, 7,893 people died, including 4220 people due to cardiovascular diseases (CVD). The KaplanMeier curves was used to assess the associations between IC categories and survival. The risk of death, including due to CVD, was assessed using Cox proportional hazard models.

Results. There were 38,8% of men with leg pain. The prevalence of IC in the studied sample was 1,0%, increasing with age from 0,4 to 2,3% in the older age group. As expected, individuals without leg pain live the longest. The years of life lost in persons with IC was 12. This parameter for cardiovascular deaths was 22,4 years. The contribution to survival not only of IC (P3), but also of atypical pain (P2) remains significant regardless of age. Moreover, the results of multivariate analysis showed that the contribution to mortality of P3 and P2 does not depend on increased blood pressure, smoking, ischemic and other electrocardiographic abnormalities, a history of myocardial infarction, which indicates the common etiology of lower limb and heart artery diseases. Similar data were obtained regarding cardiovascular mortality, however, the contribution of CI is more significant.

Conclusion. IC In Russian men aged 35-70 years is an independent predictor of all-cause and cardiovascular death.

Health-related quality of life amongst people diagnosed with abdominal aortic aneurysm and peripheral artery disease and the effect of fenofibrate

The aims of this study were, firstly, to assess the effect of concurrent peripheral artery disease (PAD) on the health-related quality of life (QOL) of people diagnosed with a small abdominal aortic aneurysm (AAA); and secondly, to test whether the peroxisome proliferator-activated receptor α agonist fenofibrate improved QOL of people diagnosed with a small AAA, including those diagnosed with concurrent PAD. The study included both a cross-sectional observational study and a randomized placebo-controlled clinical trial. 140 people diagnosed with a 35-49 mm diameter AAA, 56 (40%) of whom had concurrent PAD, and 25 healthy controls were prospectively recruited. QOL was assessed with the short form (SF) 36. Findings in participants that were diagnosed with both AAA and PAD were compared separately with those of participants that had a diagnosis of AAA alone or who had neither AAA nor PAD diagnosed (healthy controls). All participants diagnosed with an AAA were then randomly allocated to 145 mg of fenofibrate per day or identical placebo. Outcomes were assessed by changes in the domains of the SF-36 and ankle brachial pressure Index (ABPI) from randomization to 24 weeks. Data were analyzed using Mann-Whitney U tests. Participants diagnosed with both AAA and PAD had significantly worse QOL than participants diagnosed with AAA alone or healthy controls. Fenofibrate did not significantly alter SF-36 scores or ABPI over 24 weeks. Fenofibrate does not improve QOL of people diagnosed with small AAA, irrespective of whether they have concurrent PAD.Trial registration: ACTN12613001039774 Australian New Zealand Clinical Trials Registry.

Relationship Between Disease Specific Quality of Life Measures, Physical Performance, and Activity in People with Intermittent Claudication Caused by Peripheral Artery Disease

OBJECTIVE

The aims of this study were firstly to assess the correlation between disease specific measures of quality of life (QOL) and physical performance and activity, and secondly to identify demographic, clinical, functional, and physical activity measures independently associated with QOL in people with intermittent claudication.

METHODS

This was a cross sectional observational study of 198 people with intermittent claudication caused by peripheral artery disease who were recruited prospectively. QOL was assessed with the intermittent claudication questionnaire (ICQ) and the eight-theme peripheral artery disease quality of life questionnaire. Physical performance was assessed with the six minute walk test (6MWT) and short physical performance battery (SPPB), and an accelerometer was used to measure seven day step count. The associations between QOL scores and 6MWT distance, SPPB scores and seven day step count were examined using Spearman Rho's (ρ) correlation and multivariable linear regression.

RESULTS

ICQ scores were significantly correlated with 6MWT distance (ρ = 0.472, p < .001), all four SPPB scores (balance ρ = 0.207, p = .003; gait speed ρ = 0.303, p < .001; chair stand ρ = 0.167, p = .018; total ρ = 0.265, p < .001), and seven day step count (ρ = 0.254, p < .001). PADQOL social relationships and interactions (ρ = 0.343, p < .001) and symptoms and limitations in physical functioning (ρ = 0.355, p < .001) themes were correlated with 6MWT distance. The 6MWT distance was independently positively associated with ICQ and both PADQOL theme scores (ICQ: B 0.069, p < .001; PADQOL social relationships and interactions: B 0.077, p < .001; PADQOL symptoms and limitations in physical functioning: B 0.069, p < .001).

CONCLUSION

Longer 6MWT distance independently predicted better physical and social aspects of QOL in people with intermittent claudication supporting its value as an outcome measure.

Association between calf muscle oxygen saturation with ambulatory function and quality of life in symptomatic patients with peripheral artery disease

OBJECTIVE

The objective of this study was to determine whether calf muscle hemoglobin oxygen saturation (Sto₂) obtained during a standardized treadmill test is associated with ambulatory function and health-related quality of life (HRQoL) in patients with symptomatic peripheral artery disease (PAD). We hypothesized that a rapid decline in calf muscle Sto₂ during walking is associated with impaired ambulatory function and HRQoL and that these associations are independent of ankle-brachial index (ABI).

METHODS

Calf muscle Sto₂, peak walking time, and claudication onset time were obtained during a treadmill test in 151 symptomatic men and women with PAD. Patients were further characterized by demographic variables, comorbid conditions, cardiovascular risk factors, ABI, 6-minute walk distance, daily ambulatory activity, Walking Impairment Questionnaire (WIQ) score, and Medical Outcomes Study 36-Item Short Form Health Survey physical function score to assess HRQoL.

RESULTS

The median calf muscle Sto₂ value at rest was 52%, which declined to 22% after only 1 minute of walking during the treadmill test and reached a minimum value of 9% after a median time of 87 seconds of walking. Of the various calf muscle Sto₂ measurements obtained during the treadmill test, the exercise time to the minimum calf muscle Sto₂ value (log transformed) had the strongest univariate associations with peak walking time (r = 0.56; P < .001), claudication onset time (r = 0.49; P < .001), 6-minute walk distance (r = 0.31; P < .001), WIQ distance score (r = 0.33; P < .001), WIQ speed score (r = 0.39; P < .001), WIQ stair-climbing score (r = 0.37; P < .001), and Medical Outcomes Study 36-Item Short Form Health Survey physical function score (r = 0.32; P < .001). In adjusted multiple regression models, these associations persisted (P < .001) after adjustment for demographic measures, cardiovascular risk factors, comorbid conditions, and ABI.

CONCLUSIONS

More rapid decline in oxygen saturation of the calf musculature during walking, indicative of impaired microcirculation, is predictive of impaired ambulatory function and HRQoL in patients with symptomatic PAD. Of particular importance, these associations are independent of ABI and other common health burdens, highlighting the clinical relevance that the microcirculation has on ambulatory function and HRQoL in patients with symptomatic PAD.

Quality of life in patients with intermittent claudication

Background

Intermittent claudication (IC) is a common condition that causes pain in the lower limbs when walking and has been shown to severely impact the quality of life (QoL) of patients. The QoL is therefore often regarded as an important measure in clinical trials investigating intermittent claudication. To date, no consensus exits on the type of life questionnaire to be used. This review aims to examine the QoL questionnaires used in trials investigating peripheral arterial disease (PAD).

Material and methods

A systematic review of randomised clinical trials including a primary analysis of QoL via questionnaire was performed. Trials involving patients with diagnosed PAD were included (either clinically or by questionnaire). Any trial which had QoL as the primary outcome data was included with no limit being placed on the type of questionnaire used.

Results

The search yielded a total of 1845 articles of which 31 were deemed appropriate for inclusion in the review. In total, 14 different QoL questionnaires were used across 31 studies. Of the questionnaires 24.06% were missing at least one domain when reported in the results of the study. Mean standard deviation varied widely based on the domain reported, particularly within the SF36.

Discussion

Despite previous recommendations for Europewide standardisation of quality of life assessment, to date no such tool exists. This review demonstrated that a number of different questionnaires remain in use, that their completion is often inadequate and that further evidence-based guidelines on QoL assessment are required to guide future research.

Efficacy of brief behavioral counselling by allied health professionals to promote physical activity in people with peripheral arterial disease (BIPP): study protocol for a multi-center randomized controlled trial

Background

Physical activity is recommended for people with peripheral arterial disease (PAD), and can improve walking capacity and quality of life; and reduce pain, requirement for surgery and cardiovascular events. This trial will assess the efficacy of a brief behavioral counselling intervention delivered by allied health professionals to improve physical activity in people with PAD.

Methods

This is a multi-center randomised controlled trial in four cities across Australia. Participants (N = 200) will be recruited from specialist vascular clinics, general practitioners and research databases and randomised to either the control or intervention group. Both groups will receive usual medical care, a written PAD management information sheet including advice to walk, and four individualised contacts from a protocol-trained allied health professional over 3 months (weeks 1, 2, 6, 12). The control group will receive four 15-min telephone calls with general discussion about PAD symptoms and health and wellbeing. The intervention group will receive behavioral counselling via two 1-h face-to-face sessions and two 15-min telephone calls. The counselling is based on the 5A framework and will promote interval walking for 3 × 40 min/week. Assessments will be conducted at baseline, and 4, 12 and 24 months by staff blinded to participant allocation. Objectively assessed outcomes include physical activity (primary), sedentary behavior, lower limb body function, walking capacity, cardiorespiratory fitness, event-based claudication index, vascular interventions, clinical events, cardiovascular function, circulating markers, and anthropometric measures. Self-reported outcomes include physical activity and sedentary behavior, walking ability, pain severity, and health-related quality of life. Data will be analysed using an intention-to-treat approach. An economic evaluation will assess whether embedding the intervention into routine care would likely be value for money. A cost-effectiveness analysis will estimate change in cost per change in activity indicators due to the intervention, and a cost-utility analysis will assess change in cost per quality-adjusted life year. A full uncertainty analysis will be undertaken, including a value of information analysis, to evaluate the economic case for further research.

Discussion

This trial will evaluate the efficacy and cost-effectiveness of a brief behavioral counselling intervention for a common cardiovascular disease with significant burden.

Trial registration

ACTRN 12614000592640 Australian New Zealand Clinical Trials Registry. Registration Date 4 June 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3801-7) contains supplementary material, which is available to authorized users.

Burden of peripheral arterial disease in Europe and the United States: a patient survey

BACKGROUND

The aim of the current study was to quantify the burden of peripheral arterial disease (PAD) with respect to health-related quality of life, work productivity and activity impairment, and healthcare resource utilization.

METHODS

Data were obtained from the 2010 EU National Health and Wellness Survey (NHWS), which included participants from France, Germany, Italy, Spain, and the UK (5 EU, N = 57,805) as well as the 2010 US NHWS (N = 75,000). The NHWS is an annual, cross-sectional, self-administered Internet survey which employs a stratified random sampling frame to match the age and gender characteristics of the NHWS sample with known population statistics. Participants who self-reported a diagnosis of PAD were compared with participants who did not self-report a diagnosis of PAD on health-related quality of life (mental and physical component summary scores and health utilities from the Short Form-12v2), work productivity and activity impairment (Work Productivity and Activity Impairment questionnaire), and healthcare resource use in terms of the number of physician visits, emergency room visits, and hospitalizations in the past six months through regression modeling adjusting for demographics and health characteristics.

RESULTS

A total of 743 (1.29%) and 777 (1.04%) participants self-reported a diagnosis of PAD in the 5 EU and US, respectively. After adjusting for demographics and health characteristics, patients with PAD reported worse health-related quality of life, as measured by health utilities (5 EU: 0.66 vs. 0.70; US: 0.66 vs. 0.72; all p < .05), greater overall work impairment percentage (5 EU: 38.27% vs. 27.48%; US: 23.89% vs. 14.26%) and greater healthcare resource use compared to participants without PAD (all p < .05).

CONCLUSIONS

These results suggest a significant burden for patients with PAD in both the 5 EU countries and the US with respect to both quality of life and economic outcomes. Improved management of these patients may have profound effects from both patient and societal perspectives.

A program of 3 physical therapy modalities improves peripheral arterial disease in diabetes type 2 patients: a randomized controlled trial

BACKGROUND AND OBJECTIVE

Type 2 diabetes is one of the main causes of peripheral vascular disease. The beneficial effects of exercise on glucose homeostasis include a marked stimulation of blood glucose utilization during and after its performance. The objective of this study was to determine the effects of a program of 3 physical therapy modalities on blood circulation in patients with type 2 diabetes with peripheral arterial disease.

SUBJECTS AND METHOD

A randomized controlled trial was undertaken. Sixty-eight patients with type 2 diabetes with Leriche-Fontaine stage I or IIa peripheral arterial disease were randomly assigned to an exercise or placebo group. For 20 weeks, the exercise group underwent treatment comprising 3 exercises at proximal, medium, and distal segments of the lower limbs, and the placebo group received sham treatment with disconnected ultrasound equipment. Peripheral arterial disease was determined by evaluating the ankle/brachial index (ABI), Doppler flow velocity, blood parameters, cardiovascular risk score, and heart rate during exercise test.

RESULTS

After 20 weeks of treatment, significant differences between groups were found in the following: right (P < .039) and left (P < .023) ABI; Doppler flow velocity (cm/s) in the right (P < .010) and left (P < .026) posterior tibial artery and in the right (P < .012) and left (P < .022) dorsalis pedis artery; and fibrinogen (P < .045), hemoglobin (P < .021), cholesterol (P < .012), high-density lipoprotein cholesterol (P < .031), and HbA1c (P < .034) values. There was no significant difference in low-density lipoprotein cholesterol values (P < .110) between the groups.

CONCLUSION

A program of these physical therapy modalities improves ABI, Doppler flow velocity, and blood parameters in patients with type 2 diabetes.

Predictors of walking capacity in peripheral arterial disease patients

OBJECTIVE

To estimate walking capacity in intermittent claudication patients through a prediction model based on clinical characteristics and the walking impairment questionnaire.

METHODS

The sample included 133 intermittent claudication patients of both genders aged between 30 and 80 years. Data regarding clinical characteristics, the walking impairment questionnaire and treadmill walking test performance were obtained. Multiple regression modeling was conducted to predict claudication onset distance and total walking distance using clinical characteristics (age, height, mass, body mass index, ankle brachial index lower, gender, history of smoking and co-morbid conditions) and walking impairment questionnaire responses. Comparisons of claudication onset distance and total walking distance measured during treadmill tests and estimated by a regression equation were performed using paired t-tests.

RESULTS

Co-morbid conditions (diabetes and coronary artery disease) and questions related to difficulty in walking short distances (walking indoors - such as around your house and walking 5 blocks) and at low speed (walking 1 block at average speed - usual pace) resulted in the development of new prediction models high significant for claudication onset distance and total walking distance (p<0.001). In addition, non-significant differences from the results obtained by the treadmill test and estimated by the current model (p>0.05) were observed.

CONCLUSION

The current study demonstrated that walking capacity can be adequately estimated based on co-morbid conditions and responses to the walking impairment questionnaire.

Effects of a 6-month exercise program pilot study on walking economy, peak physiological characteristics, and walking performance in patients with peripheral arterial disease

The purpose of this study was to examine the effects of a 6-month exercise program on submaximal walking economy in individuals with peripheral arterial disease and intermittent claudication (PAD-IC). Participants (n = 16) were randomly allocated to either a control PAD-IC group (CPAD-IC, n = 6) which received standard medical therapy, or a treatment PAD-IC group (TPAD-IC; n = 10) which took part in a supervised exercise program. During a graded treadmill test, physiological responses, including oxygen consumption, were assessed to calculate walking economy during submaximal and maximal walking performance. Differences between groups at baseline and post-intervention were analyzed via Kruskal–Wallis tests. At baseline, CPAD-IC and TPAD-IC groups demonstrated similar walking performance and physiological responses. Postintervention, TPAD-IC patients demonstrated significantly lower oxygen consumption during the graded exercise test, and greater maximal walking performance compared to CPAD-IC. These preliminary results indicate that 6 months of regular exercise improves both submaximal walking economy and maximal walking performance, without significant changes in maximal walking economy. Enhanced walking economy may contribute to physiological efficiency, which in turn may improve walking performance as demonstrated by PAD-IC patients following regular exercise programs.