The Effect of Arterial Disease Level on Outcomes of Supervised Exercise Therapy for Intermittent Claudication: A Prospective Cohort Study

Patient Reported Barriers for Participation in Supervised Exercise Therapy for Symptomatic Peripheral Artery Disease

BACKGROUND

Supervised exercise therapy (SET) provides clinical benefit for patients suffering from intermittent claudication due to peripheral artery disease (PAD). However, enrollment in programs when offered remains low. We sought to identify patient-reported barriers to enrollment in SET as part of a prospective quality improvement program.

METHODS

Patients who presented to clinic and were diagnosed with claudication were offered enrollment in a prospective quality improvement protocol, offered at 9 regional offices throughout our health system. Both patients who enrolled and declined enrollment were offered a 12-question questionnaire to identify potential barriers to enrollment. Additional data including gender, smoking status, ankle-brachial index (ABI), proximity to the nearest regional office, and disadvantage levels of neighborhoods (low: 1-3, medium: 4-7, and high: 8-10 area deprivation index [ADI]) was collected and compared by program participation using univariate analysis.

RESULTS

Patients enrolled in the SET program (n = 66 patients) versus those who declined (n = 84 patients) were of similar age (medium age: 71.4 vs. 69.7 years, P = 0.694), baseline ABI (0.6 vs. 0.6, P = 0.944), smoking status (former 56.1% vs. 53.6%, P = 0.668), distance away from outpatient center (8.2 mi vs. 8.4 mi, P = 0.249), and had similar Connecticut state ADIs (2021 high-disadvantage: 35.4% vs. 33.3%, P = 0.549). Patients participating in the SET program were more likely to be male (78.8% vs. 56.0%, P = 0.003). Top self-reported barriers for patients who declined participation included transportation/distance (39.3%), preference for independent walking (56.0%), inability to commit to 3 sessions per week (52.4%), and lack of interest (20.2%). In addition, a higher proportion of patients who declined participation identified severe barriers of preference for independent walking (39.3% vs. 1.5%, P < 0.001), inability to commit to 3 sessions per week (26.2% vs. 3.0% P < 0.001), transportation/distance issues (23.8% vs. 7.6% P = 0.008), and cost (27.4% vs. 9.1%, P = 0.005) as significant barriers for participation in SET.

CONCLUSIONS

Patients who declined participation in SET for PAD had similar disease status and access to care than participating counterparts. Top reported barriers to enrollment include a preference for independent walking, transportation/distance, commitment to 3x/week program, and cost, which highlight areas of focus for equitable access to these limb-saving services.

Supervised Exercise Therapy is Effective for Patients With Intermittent Claudication Regardless of Psychological Constructs

OBJECTIVE

According to current guidelines, supervised exercise therapy (SET) is the treatment of choice for intermittent claudication (IC). Little is known about the potential consequences of psychological factors on the effectiveness of treatment. The aim of this study was to determine possible associations between a set of psychological constructs and treatment outcomes, and to investigate whether self efficacy increased after SET.

METHODS

This was a substudy of the ELECT Registry, a multicentre Dutch prospective cohort study in patients with IC receiving primary SET. A complete set of validated questionnaires scoring extraversion, neuroticism, conscientiousness, anxiety, depression, self control, optimism, and self efficacy was obtained in 237 patients (median age 69 years, 40% female). Anxiety and depression were dichotomised using established cutoff scores, whereas other scores were analysed as continuous measures. Multiple linear regression analyses determined possible associations between these independent variables and maximum and functional walking distances (MWD and FWD, respectively), Six Minute Walk Test (6MWT), and VascuQol-6 (dependent variables). Self efficacy during 12 months of SET was analysed using a linear mixed model.

RESULTS

Neuroticism and anxiety were associated with lower overall VascuQol-6 scores (estimate -1.35 points [standard error (SE) 0.57; p = .018] and -1.98 points [SE 0.87, p = .023], respectively). Optimism and self efficacy demonstrated higher overall 6MWT (5.92 m [SE 2.34; p = .012] and 1.35 m [SE 0.42; p = .001], respectively). Self control was associated with lower overall log MWD (-0.02 [SE 0.01; p = .038] and log FWD (-0.02 [SE 0.01; p = .080), whereas self efficacy had a higher overall log MWD (0.01 [SE 0.003; p = .009]) and log FWD (0.01 [SE 0.003; p = .011]). Depressive patients with IC demonstrated a greater improvement in 6MWT during follow up (17.56 m [SE 8.67; p = .044]), but this small effect was not confirmed in sensitivity analysis. Self efficacy did not increase during follow up (0.12% [SE 0.49; p = .080]).

CONCLUSIONS

The beneficial effects of SET occur regardless of the psychological constructs, supporting current guidelines recommending a SET first strategy in each patient with IC.

Vascular Quality of Life Questionnaire-6 Before and After Supervised Exercise Therapy in Patients with Intermittent Claudication

OBJECTIVE

The Vascular Quality of Life Questionnaire-6 (VascuQoL-6) is a short, disease specific instrument used to determine health related quality of life (HRQoL) in patients with peripheral arterial disease. This study aimed to assess the minimally important difference (MID) and substantial clinical benefit (SCB) of the VascuQoL-6 in Dutch patients with intermittent claudication (IC) receiving supervised exercise therapy (SET).

METHODS

Consecutive patients with IC who were recruited from a single centre between January 2016 and December 2016 completed the VascuQoL-6 before initiation and after three months of SET. They subsequently answered an anchor question rating their current health status as much improved, improved, unchanged, deteriorated, or much deteriorated, compared with baseline. The MID for improvement and deterioration and SCB were calculated using anchor based and distribution based methods.

RESULTS

A total of 124 patients with IC (58% male, mean age 68 years) completed the study protocol. Baseline VascuQoL-6 scores increased from 16.3 ± 4.4 to 18.7 ± 3.8 after three months of SET (p < .001). MID values ranged from +2.0 to +3.8 points regarding HRQoL improvement and from +0.2 to -2.2 points regarding HRQoL deterioration. The SCB ranged from +3.7 to +5.0 points. Depending on the MID approach, 32% - 41% of patients achieved a clinically meaningful improvement in HRQoL.

CONCLUSION

Approximately one in three patients with IC reported a clinically meaningful improvement in HRQoL after three months of SET. The range of MID and SCB values provides caregivers with an idea of how much change in VascuQoL-6 scores is considered relevant or substantial by their patients. Applying cutoff points for MID and SCB may optimise the interpretation of trial results and may help to set a benchmark for success of SET.

A Comparison of Health Status and Quality of Life in Patients with Intermittent Claudication

BACKGROUND

Patient reported outcome measures (PROMs) such as health status (HS) and quality of life (QOL) are frequently used interchangeably while they represent different outcomes. Whether a discrepancy exists in patients with intermittent claudication (IC) in changes over time between HS and QOL is unclear. This study aimed to investigate the strength and the direction of the association between HS and QOL over time in patients with IC that underwent supervised exercise therapy (SET).

MATERIAL AND METHODS

Patients were part of the ELECT multi-center prospective cohort study. One goal of this study was to obtain data on HS and QOL at different time intervals of patients with IC that underwent SET. HS (VascuQOL-6) and QOL (WHOQOL-BREF) were completed at baseline, 3 months, and 6 months follow up. Pearson's correlation coefficients and the associated common variances (R²) were calculated to measure the strength and the direction of the association between HS and QOL in changes between baseline and follow-up moments.

RESULTS

In total, 177 patients were included in data analyses. Only changes in physical QOL and overall QOL had a small correlation with changes over time in HS, at both 3- and 6 months follow up (respectively R²=.14; P < 0.001 and R² = 0.12; P < 0.001 for physical QOL and R² = 0.18; P < 0.001 and R² = 0.13; P < 0.001 for overall QOL).

CONCLUSIONS

This study showed that HS and QOL provide different outcomes in patients with IC that underwent SET. Future studies should be aware of these differences before PROMs are being incorporated as an outcome measure in clinical studies.