Key Points
Question
Does a brief counseling intervention delivered by allied health professionals increase step count by people with peripheral artery disease (PAD)?
Finding
In this randomized clinical trial including 200 participants with PAD, a brief counseling intervention did not significantly increase step count over 4 months compared with a control group, but it did improve disease-specific quality of life.
Meaning
More intensive or differently designed interventions are needed to effectively increase walking in people with PAD.
This randomized clinical trial evaluates whether brief counseling delivered by allied health professionals increases step count in participants with peripheral artery disease.
Abstract
Importance
It is unclear how to effectively promote walking in people with peripheral artery disease (PAD).
Objective
To test whether brief counseling delivered by allied health professionals increases step count in participants with PAD.
Design, Setting, and Participants
In this randomized clinical trial, participants with symptomatic PAD were recruited from sites in Australia and randomly allocated 1:1 to the counseling intervention or an attention control. Data were collected from January 2015 to July 2021, and data were analyzed from March to November 2022.
Interventions
Two 1-hour face-to-face and two 15-minute telephone counseling sessions designed to increase walking.
Main Outcomes and Measures
The primary outcome was the between-group difference in change in daily step count estimated by accelerometer recordings over 7 days at baseline and 4 months, using imputation for missing values. Other outcomes at 4, 12, and 24 months included step count, 6-minute walk distance, and disease-specific and generic measures of health-related quality of life. Risk of major adverse limb events was assessed over 24 months.
Results
Of 200 included participants, 144 (72.0%) were male, and the mean (SD) age was 69.2 (9.3) years. The planned sample of 200 participants was allocated to the counseling intervention group (n = 102) or attention control group (n = 98). Overall, 198 (99.0%), 175 (87.5%), 160 (80.0%) and 143 (71.5%) had step count assessed at entry and 4, 12, and 24 months, respectively. There was no significant between-group difference in the primary outcome of change in daily step count over 4 months (mean steps, 415; 95% CI, −62 to 893; P = .07). Participants in the counseling group had significantly greater improvement in the secondary outcome of disease-specific Intermittent Claudication Questionnaire score at 4 months (3.2 points; 95% CI, 0.1-6.4; P = .04) and 12 months (4.3 points; 95% CI, 0.5-8.1; P = .03) but not at 24 months (1.2 points; 95% CI, −3.1 to 5.6; P = .57). Findings were similar for mean PAD Quality of Life Questionnaire component assessing symptoms and limitations in physical functioning (4 months: 1.5 points; 95% CI, 0.3-2.8; P = .02; 12 months: 1.8 points; 95% CI, 0.3-3.3; P = .02; 24 months: 1.3 points; 95% CI. −0.5 to 3.1; P = .16). There was no significant effect of the intervention on change in mean 6-minute walking distance (4 months: 9.3 m; 95% CI, −3.7 to 22.3; P = .16; 12 months: 13.8 m; 95% CI, −4.2 to 31.7; P = .13; 24 months: 1.2 m; 95% CI, −20.0 to 22.5; P = .91). The counseling intervention did not affect the rate of major adverse limb events over 24 months (12 [6.0%] in the intervention group vs 11 [5.5%] in the control group; P > .99).
Conclusions and Relevance
This randomized clinical trial found no significant effect of brief counseling on step count in people with PAD. Alternate interventions are needed to enable walking.
Trial Registration
Australian New Zealand Clinical Trials Registry Identifier: ACTRN12614000592640
Introduction
Walking is an established treatment for peripheral artery disease (PAD), but advice from physicians to walk is frequently not followed.1,2 A randomized clinical trial including 58 people with PAD found that a brief counseling intervention consisting of 2 face-to-face sessions and 2 phone calls significantly increased steps walked and reduced requirement for revascularization over 2 years.3 The intervention was delivered by a psychologist and included home visits, which may not be feasible in routine practice.
The Brief Behavioral Intervention by Allied Health Professionals to Promote Physical Activity (BIP) trial tested whether a brief counseling intervention delivered by allied health professionals, trained in a counseling protocol and delivered using 2 face-to-face sessions at a central facility and 2 phone calls, increased steps walked in people with PAD over 4 months. Secondary aims were to test the effect of the intervention on steps walked, walking distance, Short Physical Performance Battery (SPPB), quality of life (QOL), and major adverse limb events over 2 years.
Methods
The BIP trial was a parallel, 1:1, multicenter randomized clinical trial and was reported according to the Consolidated Standards of Reporting Trials (CONSORT) reporting guideline. The protocol was published.4 Investigator roles can be found in the eAppendix in Supplement 1. The trial complied with the Declaration of Helsinki and was approved by the Royal Brisbane and Women’s Hospital Human Research Ethics Committee as well as local ethics committees and registered prior to commencement. All participants provided written informed consent. Eligibility included symptomatic PAD, ability to walk without assistance, no current involvement in an exercise program, no planned vascular intervention, and ability to understand a behavior intervention. People with ischemic rest pain, ulceration, or gangrene were excluded. Prior revascularization was not an exclusion. Participants were recruited from vascular departments in Brisbane, Sydney, and Townsville, Australia.
Random group allocation occurred via a secure independent website and was stratified by ankle-brachial index (ABI less than 0.50, 0.50-0.69, 0.70-0.89, and greater than 1.4), site, and sex. Allocation was masked by using different staff for outcome assessment and delivery of the intervention and control and by telling participants they would receive advice using a range of information modalities. The intervention and attention control sessions were delivered by allied health professionals who were not registered psychologists or counselors. Staff were trained by the study psychologist (N.W.B.) in a 6-hour face-to-face workshop, given a written manual, and required to achieve more than 80% in a competency-based assessment.4 All participants received written information on PAD and recommendations to walk at least 3 times a week for 40 minutes.4
The intervention consisted of two 1-hour face-to-face (weeks 1 and 2) and two 15-minute telephone sessions (weeks 6 and 12). The counseling followed the 5A Framework and included: (1) assessment of knowledge about PAD and walking and barriers and enablers for walking; (2) advice about the benefit of walking to treat PAD; (3) collaborative agreement on walking goals of three 40-minute sessions per week of interval walking at maximum tolerated speed (ie, moderate pain levels); (4) assistance with action plans, self-regulation, outcome expectations, self-monitoring, social support, and problem solving; and (5) arranging next contact. Attention control consisted of four 15-minute telephone calls at the same time points as the intervention. Contacts involved open-ended questions about symptoms and well-being with empathic, nondirective responses. All sessions were recorded and approximately 10% randomly examined for fidelity using a custom-made 20-item checklist.
The primary outcome was the between-group difference in the change in daily step count over 4 months measured by a thigh-placed activPAL3 accelerometer (PAL Technologies) recording over 7 days.5 Secondary outcomes included step counts at 12 and 24 months, 6-minute walk test distance, and the SPPB score assessed at 4, 12, and 24 months using standard protocols.6 At entry and 4, 12 and 24 months, QOL was assessed using the 36-Item Short Form Health Survey, the Intermittent Claudication Questionnaire (ICQ), and the PAD Quality of Life Questionnaire (PADQOL) questionnaire.7,8 Major adverse limb events were assessed from interviews and documented hospital records and defined as requirement for lower limb revascularization or major amputation. Adverse events were defined according to Good Clinical Practice guidelines, and ascertained at interviews at 4, 12, and 24 months.9 Serious adverse events were validated through review of hospital records and assessed by an independent safety committee.
The sample size of 200 was calculated to test with 90% power (2-tailed α of .05; within-participant between-visit correlation of 0.6; dropout rate of 40%) a hypothesized mean (SD) daily step counts of 5000 (3400) for those in the intervention group compared with 3300 (2200) in the control group at 4 months.3 The primary outcome and continuous secondary outcomes were tested using linear mixed models. The effect of the intervention on major adverse limb events was assessed with Kaplan-Meier analysis. The analysis of the primary outcome, but not other outcomes, included log transformation to correct kurtosis and imputation of missing data. Imputation of multiple outcomes was avoided as it can introduce error owing to nonrandom distribution of missing values. The main analysis was unadjusted, and a further analysis adjusted for the stratification factors. All analyses were conducted using R version 4.2.0 (The R Foundation).
Results
Between January 2015 and July 2018, 200 participants were allocated to the intervention group (n = 102) or control group (n = 98). Of these, 144 (72.0%) were male, and the mean (SD) age was 69.2 (9.3) years. Overall, 198 (99.0%), 175 (87.5%), 160 (80.0%) and 143 (71.5%) had step counts assessed at entry and 4, 12, and 24 months, respectively (Figure; eTable 1 in Supplement 1). The risk factors and medications at baseline were similar in each group (Table 1). In the intervention group, 81 participants (79.4%) attended all 4 intervention sessions and 13 (12.7%) attended between 1 and 3 sessions, while in the control group, 71 (72%) attended all 4 control sessions and 22 (22%) attended between 1 and 3 sessions (Figure). A total of 30 of 31 intervention sessions (97%) and 28 of 28 control sessions (100%) examined by a blinded fidelity assessor were correctly identified. Key components of the counseling framework were rated as implemented inconsistently (eResults in Supplement 1).
Figure. Flow of Included Participants.
Some participants completed some but not all outcome assessments when assessed at 4, 12, and 24 months as they declined or were unable to do some of the outcome tests due to illness, adverse events, or personal reasons. See eTable 1 in Supplement 1 for a detailed list of number of participants that completed each assessment.
aFour completed some but not all outcome assessments.
bThree completed some but not all outcome assessments.
cSeven completed some but not all outcome assessments.
dTwo completed some but not all outcome assessments.
eFive completed some but not all outcome assessments.
Table 1. Baseline Characteristics of Participants.
| Characteristic | No. (%) | |
|---|---|---|
| Intervention group (n = 102) | Control group (n = 98) | |
| Demographic characteristics | ||
| Age, mean (SD), y | 68.3 (9.7) | 70.1 (8.8) |
| Sex | ||
| Female | 29 (28.4) | 27 (27.6) |
| Male | 73 (71.6) | 71 (72.4) |
| BMI, mean (SD)a | 28.6 (6.0) | 28.5 (5.0) |
| Waist-hip ratio, mean (SD) | 0.99 (0.10) | 0.99 (0.08) |
| Lowest ABI, mean (SD) | 0.67 (0.23) | 0.68 (0.22) |
| Smoking history | ||
| Never | 10 (9.8) | 7 (7.1) |
| Former | 53 (52.0) | 64 (65.3) |
| Current | 39 (38.2) | 27 (27.6) |
| Medical history | ||
| Hypertension | 76 (74.5) | 81 (82.7) |
| Dyslipidemia | 89 (87.3) | 87 (88.8) |
| Diabetes | 31 (30.4) | 35 (35.7) |
| Stroke | 11 (10.8) | 15 (15.3) |
| CHD | 41 (40.2) | 52 (53.1) |
| COPD | 30 (29.4) | 25 (25.5) |
| Cancer | 37 (36.3) | 29 (29.6) |
| Prior peripheral revascularization | 42 (41.2) | 38 (38.8) |
| Physical function measures, mean (SD) | ||
| 6-min Walking distance, m | 371.8 (93.3) | 372.5 (102.3) |
| Daily step countb | 5330 (2687) | 4952 (2294) |
| SPPB | ||
| Balance score | 3.8 (0.6) | 3.7 (0.6) |
| Gait speed score | 3.4 (0.8) | 3.4 (0.7) |
| Chair stand score | 2.4 (1.2) | 2.3 (1.2) |
| Total score | 9.5 (2.0) | 9.4 (1.9) |
| Quality of life measures, mean (SD) | ||
| SF-36 | ||
| PCS | 35.8 (8.7) | 34.7 (9.7) |
| MCS | 50.9 (12.9) | 52.5 (9.7) |
| ICQ, % | 72.2 (14.3) | 72.2 (15.2) |
Abbreviations: ABI, ankle-brachial index; BMI, body mass index; CHD, coronary heart disease; COPD, chronic obstructive pulmonary disease; ICQ, Intermittent Claudication Questionnaire (percentage of maximum possible score); MCS, Mental Component Summary; PCS, Physical Component Summary; SF-36, 36-Item Short Form Health Survey; SPPB, Short Physical Performance Battery.
Calculated as weight in kilograms divided by height in meters squared.
Step counts were unavailable for 2 participants (1 allocated to each group), who were not able to perform the activity assessment because of serious adverse events. These participants withdrew after randomization but before assessment of physical activity.
Primary Outcome
Mean (SD) daily step count was 5330 (2687) at baseline and 5859 (2893) at 4 months in the intervention group compared with 4952 (2294) at baseline and 5066 (2424) at 4 months in the control group, using multiple imputation for 23 missing values at 4 months (intergroup mean step difference, 415; 95% CI, −62 to 893; P = .07) (Table 2; eFigure 1 in Supplement 1).
Table 2. Outcomes From the BIP Triald.
| Outcome | Mean (SD) | Intergroup difference in change (modeled)a | ||||
|---|---|---|---|---|---|---|
| Intervention (observed values) | Control (observed values) | Unadjusted | Adjustedb | |||
| Baseline | Follow-up | Baseline | Follow-up | |||
| Primary outcome | ||||||
| Between-group difference in change in daily step count from baseline to 4 mo (includes imputed data at 4 mo) | 5330 (2687) | 5859 (2893) | 4952 (2294) | 5066 (2424) | 415 (−62 to 893) | 439 (−16 to 895) |
| Secondary outcomes | ||||||
| Steps per day | ||||||
| Baseline vs 12 mo | 5330 (2687) | 5502 (2989) | 4952 (2294) | 4898 (2169) | 200 (−312 to 712) | 197 (−315 to 709) |
| Baseline vs 24 mo | 5330 (2687) | 5205 (2639) | 4952 (2294) | 4707 (2300) | 39 (−506 to 583) | 35 (−510 to 579) |
| 6-min Walking distance, m | ||||||
| Baseline vs 4 mo | 371.8 (93.3) | 373.7 (96.3) | 372.5 (102.3) | 357.6 (107.1) | 9.3 (−3.7 to 22.3) | 9.5 (−3.5 to 22.5) |
| Baseline vs 12 mo | 371.8 (93.3) | 378.4 (96.1) | 372.5 (102.3) | 357.9 (109.9) | 13.8 (−4.2 to 31.7) | 14.0 (−4.0 to 31.9) |
| Baseline vs 24 mo | 371.8 (93.3) | 364.0 (108.5) | 372.5 (102.3) | 359.6 (104.1) | 1.2 (−20.0 to 22.5) | 1.9 (−19.3 to 23.2) |
| ICQ score, % | ||||||
| Baseline vs 4 mo | 72.2 (14.3) | 76.9 (14.8) | 72.2 (15.2) | 73.3 (17.2) | 3.2 (0.1 to 6.4)c | 3.3 (0.1 to 6.5)c |
| Baseline vs 12 mo | 72.2 (14.3) | 78.7 (16.2) | 72.2 (15.2) | 73.6 (17.9) | 4.3 (0.5 to 8.1)c | 4.4 (0.6 to 8.2)c |
| Baseline vs 24 mo | 72.2 (14.3) | 77.4 (15.6) | 72.2 (15.2) | 75.4 (16.8) | 1.2 (−3.1 to 5.6) | 1.4 (−2.9 to 5.7) |
| PADQOL Factor 3 | ||||||
| Baseline vs 4 mo | 12.7 (5.1) | 15.7 (5.9) | 13.4 (5.1) | 14.9 (5.3) | 1.5 (0.3 to 2.8)c | 1.5 (0.3 to 2.8)c |
| Baseline vs 12 mo | 12.7 (5.1) | 16.0 (5.8) | 13.4 (5.1) | 14.7 (5.6) | 1.8 (0.3 to 3.3)c | 1.8 (0.3 to 3.4)c |
| Baseline vs 24 mo | 12.7 (5.1) | 16.0 (6.1) | 13.4 (5.1) | 15.3 (6.3) | 1.3 (−0.5 to 3.1) | 1.3 (−0.5 to 3.1) |
Abbreviations: BIP, Brief Behavioral Intervention by Allied Health Professionals to Promote Physical Activity; ICQ, Intermittent Claudication Questionnaire (percentage of maximum possible score); PADQOL, PAD Quality of Life Questionnaire.
The mean difference in intergroup change in all outcome measures and P values were estimated from the interaction of time and group on linear mixed-effects models in the R statistical package. Inferences of significance for step count data were based on models in which step count were log-transformed.
Models adjusted for stratification factors (site, sex, and ankle-brachial index).
P < .05.
For details of completions and missing outcome data, see the Figure and eTable 1 in Supplement 1 . For the primary outcome, 23 missing step counts at 4 months were imputed. This involved multiple imputations (10 draws each with 50 iterations) using the R mice package. It was not possible to impute missing step counts of 2 participants who did not have accelerometer recordings at baseline or 4 months; therefore, they were omitted from the primary outcome analysis. PADQOL Factor 3 assessed symptoms and limitations in physical functioning.
Secondary Outcomes
Participants in the intervention group had significantly greater improvement in the disease-specific ICQ score at 4 months (3.2; 95% CI, 0.1-6.4; P = .04) and 12 months (4.3; 95% CI, 0.5-8.1; P = .03) but not at 24 months (1.2; 95% CI, −3.1 to 5.6; P = .57) (Table 2). In the intervention group, there were significantly greater improvements in the PADQOL components assessing symptoms and limitations in physical functioning (factor 3), social relationships and interactions (factor 1), fear and uncertainty (factor 4), and positive adaptation (factor 5) compared with the control group at 4 months (factors 3 and 5) and 12 months (factors 1, 3 and 4) (Table 2; eTable 2 in Supplement 1). There were no significant differences between groups in the other outcomes, including serious adverse events (Table 2; eTables 2 and 3 and eFigures 2 and 3 in Supplement 1).
Discussion
This randomized clinical trial found that a brief counseling intervention delivered by allied health professionals did not significantly change step count of people with PAD over 4 months compared with controls. The trial was powered to detect a mean difference of approximately 1700 steps per day between the intervention and control groups, and the observed mean difference was less than 500 steps. The intervention significantly improved the secondary outcomes of disease-specific QOL assessed with the ICQ and PADQOL at 4 and 12 months but not at 24 months. No significant difference between groups for any other outcome was found.
The intervention tested in this trial was based on an approach previously reported to increase walking by more than 1000 steps per day and reduce major adverse limb events.3 This prior intervention was delivered by a psychologist who visited participants’ homes for the face-to-face sessions. In the current trial, a range of allied health professionals at each facility were trained by a psychologist to deliver the counseling. This approach aimed to increase the discipline-free scope of service delivery but may have compromised participant engagement and therefore intervention impact. Approximately 20% of participants did not attend all counseling sessions. The requirement to attend the initial 2 sessions at the facility may have been a barrier. This could be addressed if sessions were delivered by telehealth. A slightly higher proportion of participants in the control group (27 of 98 [28%]) did not attend all 4 telephone calls. This may be because of a lack of perceived value in the generic contacts or a lack of rapport with the interventionist who they never met in person. Interventionists were trained, required to demonstrate a minimum level of competency in the protocol, and supervised monthly, but fidelity assessment indicated inconsistent quality of implementing the counseling. Future studies could include more intense training and monitoring in an attempt to improve fidelity. Use of psychologists or health counsellors to deliver the intervention and more frequent sessions may enhance the impact of the intervention.
Limitations
This study had limitations, including single country recruitment, small sample size, and not including the walking impairment questionnaire as an outcome. The significant improvements in the QOL outcomes should be interpreted cautiously given the nonsignificance of the primary outcome.
Conclusions
In conclusion, this trial found that a brief counseling intervention delivered by allied health professionals did not significantly affect step count of people with PAD.
eAppendix. BIP Investigators Roles
eResults.
eFigure 1. Effect of the Brief Behavior Counseling Intervention Compared With Controls on Change in Objectively Measured Step Count Over 4 Months
eFigure 2. Effect of the Brief Behavior Counseling Intervention Compared With Controls on Objectively Measured Step Count
eFigure 3. Effect of the Brief Behavior Counseling Intervention Compared With Controls on Freedom From Major Adverse Limb Events
eTable 1. Number of Participants That Completed Each Outcome Assessment at Baseline and Follow-up Times
eTable 2. Additional Secondary Outcomes From the BIP Trial
eTable 3. Comparison of Serious Adverse Events for Participants Allocated to Intervention and Control Groups
Group Information. BIP Investigators
Data Sharing Statement
References
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
eAppendix. BIP Investigators Roles
eResults.
eFigure 1. Effect of the Brief Behavior Counseling Intervention Compared With Controls on Change in Objectively Measured Step Count Over 4 Months
eFigure 2. Effect of the Brief Behavior Counseling Intervention Compared With Controls on Objectively Measured Step Count
eFigure 3. Effect of the Brief Behavior Counseling Intervention Compared With Controls on Freedom From Major Adverse Limb Events
eTable 1. Number of Participants That Completed Each Outcome Assessment at Baseline and Follow-up Times
eTable 2. Additional Secondary Outcomes From the BIP Trial
eTable 3. Comparison of Serious Adverse Events for Participants Allocated to Intervention and Control Groups
Group Information. BIP Investigators
Data Sharing Statement