Patient Knowledge and Preferences for Peripheral Artery Disease Treatment

Abstract

Background:

Shared medical decision making requires patients’ understanding of their disease and its treatment options. Peripheral artery disease (PAD) is a condition for which preference-sensitive treatments are available, but for which little is known about patients’ knowledge and treatment preferences as it relates to specific treatment goals.

Methods:

In a prospective, multicenter registry that involved patients with PAD experiencing claudication, the PORTRAIT Knowledge and Preferences Survey was administered at 1 year. It asks questions about PAD treatment choices, symptom relief options, disease management, and secondary prevention. PAD treatment preferences were also queried, and patients ranked 10 PAD treatment goals (1–10 Likert scale; 10 being most important).

Results:

Among 281 participants completing the survey (44.8% female, mean age 69.6±9.0 years), 54.1% knew that there was more than one way to treat PAD symptoms and 47.1% were offered more than one treatment option. Most (82.4%) acknowledged that they had to manage their PAD for the rest of their life. “Avoid loss of toes or legs”, “Decreased risk of heart attack/stroke”, “Long-lasting treatment benefit”, “Living longer”, “Improved quality of life” and “Doing what the doctor thinks I should do” had mean ratings >9.0 (SD ranging between 1.21 and 2.00). More variability occurred for “avoiding surgery”, “cost of treatment”, “timeline of pain relief”, and “return to work” (SD ranging between 2.76–3.58). The single most important treatment goal was “improving quality of life” (31.3%).

Conclusions:

Gaps exist in knowledge for patients with PAD who experience claudication, and there is a need for increased efforts to improve support for shared decision-making frameworks for symptomatic PAD.

ClinicalTrials.gov Identifier: NCT01419080

INTRODUCTION

Shared decision-making is a collaborative model that supports patients’ and clinicians’ engagement in medical treatment decision-making so that high quality decision-making can occur to align treatment with patients’ preferences and goals.¹ Shared decision-making, and decision-aids that can support this process, are becoming increasingly important to deliver more patient-centered, value-based care.^2,3 Shared decision-making approaches are particularly helpful in scenarios where conditions can be managed with different treatment options, each with their own benefits and risks.^2,4–6

A condition that lends itself particularly well for shared decision-making is peripheral artery disease (PAD).⁷ Multiple treatment options exist for PAD symptom relief and improved functional status, including medications, exercise therapy, and invasive procedures.⁸ For patients to appreciate all of the available treatment options for their PAD symptom management, and the trade-offs that are associated with each, it is critical that patients have good knowledge and understanding about their disease and its management so that they can prioritize their different PAD treatment goals. Treatment goals in PAD largely evolve around managing cardiovascular risk, symptom relief and improvement of quality of life. Previously, we have demonstrated that 70% of patients with PAD prefer to take an active role in their PAD treatment decision-making, and created a decision-aid for patients with PAD with patient and clinician stakeholders.^7,9While poor overall PAD awareness amongst those at risk or confronted with vascular complications has been shown,¹⁰ it is unknown whether those with a recent PAD diagnosis understand the various PAD treatment goals and options in PAD management as it relates to cardiovascular risk management, PAD symptom relief and quality of life improvement, and how they prioritize their various PAD treatment goals.

Embedded as a sub-study in the PORTRAIT registry,¹¹which enrolled and followed patients with new or worsening PAD symptoms at initial presentation to a vascular specialty clinic, we studied participants’ knowledge about PAD treatment benefits as it relates to cardiovascular risk management, PAD symptom relief treatment options, and associated outcomes. We also evaluated their preferences and their treatment goals related to PAD management. Understanding these factors can guide efforts to improve the shared decision-making process, as it can elicit the gaps in knowledge related to PAD treatment benefits and risks, and such information can be used to develop targeted educational strategies. In addition, understanding the variability in treatment goals and preferences, will allow us to appreciate which goals need more exploration and discussion, vs. those goals who are more universally endorsed by patients who have a diagnosis of symptomatic PAD.

METHODS

The data of this study are available from the corresponding author upon reasonable request.

Study Design and Participants

This was a pre-specified cross-sectional sub study of the US participants in the PORTRAIT study, which was a multi-center, prospective, observational registry that enrolled patients with new or worsening symptoms of PAD (Rutherford 1–3, claudication) from 10 PAD specialty clinics, including interventional cardiology, vascular surgery, and vascular medicine clinics.¹¹ Patients with new or worsening of PAD symptoms presented to these clinics for a PAD work-up and subsequent PAD management. All patients’ PAD status was documented with supporting ankle-brachial index information.¹¹All patients were treated at the discretion of the vascular specialist, focusing on cardiovascular risk management and symptom management per the established guidelines,⁸ as this was a real-world registry. Insights into their understanding of PAD and their treatment goals were collected as part of their 1-year follow up interview, after having undergone a year of PAD management, with all consecutive patients at the 10 US sites who were eligible for their 1-year follow up interview from September 14, 2015 through August 15, 2016 receiving the PAD knowledge and preferences survey. This selection of a limited time frame was chosen so as to not overburden sites and their patients in adding on questions for their follow up interviews. Institutional review board approval was received from each participating site, and all patients provided informed consent.

Measures

To assess PAD treatment knowledge, a survey of 7 knowledge (“the PORTRAIT Knowledge and Preferences Survey”^©; scored as “True”, “False”, and “Don’t know/Unsure”) and 4 preference questions (“True”, “False”, and “Don’t know/Unsure”) was designed based on the current PAD evidence-base,⁸ qualitative input from patients, and direct patient and physician expert input as part of the PORTRAIT registry protocol.¹¹ Knowledge items focused on the availability of PAD treatment choices, PAD symptom relief, chronic disease management, and secondary prevention. Statements on PAD treatment referred to the rapidity of symptom relief, avoidance of invasive strategies, smoking cessation, and exercise therapy. As part of the survey, patients also valued their PAD-related treatment goals by rating 10 PAD treatment goals on a Likert scale from 1 to 10, with 1 being the least and 10 being the most important. Patients were also asked to name their most important PAD treatment goal (See Supplemental File).

As part of the PORTRAIT registry baseline interview and medical abstraction, information was collected on patient demographics, socio-economic background, medical history, quality of PAD care, and health status information as previously described.¹¹ Baseline information was collected by trained study coordinators at each enrolling site and follow-up interviews were conducted by a centralized follow-up center organized by the call center at the Saint Luke’s Mid America Heart Institute, Kansas City, MO.¹¹

Statistical Analysis

We described patient characteristics for the total sample. Survey results were summarized at the item-level with counts and percentages. The PAD treatment goal ratings were summarized as means, medians, and standard deviations. The entries for patients’ most important PAD treatment goal were scored and ranked by percent. If a patient mentioned more than one most important PAD treatment goal, a single weight was shared proportionally between the each named goal. A comparison was also conducted for patient characteristics between those included in the study vs. the remainder of the US PORTRAIT study,¹¹ and the magnitude of the potential differences was evaluated by calculating the standardized mean differences, with effect sizes 0.20 or smaller denoting negligible differences.^12,13 Furthermore, comparisons of patient characteristics, knowledge and preferences items (Student T-tests for continuous variables, and Chi Square tests or non-parametric equivalents where indicated) were performed by whether or not patients received invasive treatment (endovascular or surgical revascularization ≤3 months of PAD work up)¹⁴ as their primary treatment was performed and standardized mean differences were calculated. Analyses were performed as complete case analysis with R version 4.1.0 in the RStudio environment.¹⁵

RESULTS

A total of 281 participants with PAD (claudication symptoms) were surveyed; of whom 44.8% was female and the mean age was 69.6±9.0 years (Table 1). Patients were 72.0% White, 24.7% Black, and 3.2% Native American or Alaska Native. Most (98.2%) were not Hispanic or Latino. The patient cohort had a mean ankle brachial index of 0.66±0.18 at baseline. Most patients had documented dyslipidemia and hypertension, over a third experienced a myocardial infarction or undergone coronary revascularization. Early invasive therapy was administered to a total of 27.8% of the patients, with the majority of them (92.3%) receiving endovascular treatment. A total of 25% were referred to smoking cessation (advice/counseling) and 1% received supervised exercised therapy. Missing covariate data ranged from 0.0 to 1.4%.

Table 1. Baseline Patient Characteristics of the PORTRAIT Knowledge and Preferences Sub study.

Values are presented as numbers (%), unless otherwise noted.

Baseline Patient Characteristics	N=281
Demographics
Age, years, mean (SD)	69.64 (9.0)
Female Sex	126 (44.8)
Race
Black	69 (24.7)
Native American/Alaska Native	9 (3.2)
White	201 (72.0)
Ethnicity
Hispanic or Latino	5 (1.8)
Not Hispanic or Latino	276 (98.2)
Married	147 (52.7)
High School Education or Above	245 (87.5)
Active Working Status	53 (19.1)
Clinical History
Mean Ankle Brachial Index Value (SD)	0.66 (0.18)
Atrial Fibrillation	41 (14.6)
Congestive Heart Failure	39 (13.9)
Dyslipidemia	251 (89.3)
Hypertension	248 (88.3)
TIA/CVA	24 (8.5)
Angina Pectoris	38 (13.5)
Myocardial Infarction	57 (20.3)
PCI/CABG	108 (38.4)
Diabetes Mellitus	107 (38.1)
Chronic Kidney Disease	42 (14.9)
Chronic Lung Disease	44 (15.7)
Current Smoker	81 (28.9)
Current or Past Smoker	248 (88.6)
Cancer	31 (11.0)
Treatments
Lower-extremity revascularization ≤3 months following enrollment	78 (27.8)
Endovascular Treatment	72/78 (92.3)
Surgical Treatment	9/78 (11.5)
Antiplatelet therapy	251 (90.0)
Statin therapy	238 (84.7)
Smoking cessation therapy (advice/counseling)	62 (25.0)
Supervised exercise therapy	9 (1)

Abbreviations: SD, Standard Deviation; TIA, Transient Ischemic Attack; CVA, Cerebrovascular Accident; PCI, Percutaneous Coronary Intervention; CABG, Coronary Artery Bypass Grafting; PAD, Peripheral Artery Disease

Regarding treatments for symptom relief, only 54.1% knew that there was more than one way to treat their PAD symptoms, and fewer than half (47.1%) were offered more than one treatment option (Figure 1, Table S1). Among those who smoked, 24.3% knew that quitting smoking may improve their symptoms. Finally, a little over a third (37.3%) thought that medications alone could be used to manage their PAD symptoms (Figure 1, Table S1).

Figure 1.

Overview of Responses to Peripheral Artery Disease Knowledge and Preferences Items (%). Abbreviations: PAD, peripheral artery disease.

With regards to the chronic nature of PAD, most (82.4%) acknowledged that they had to manage their PAD for the rest of their life, but only a third (31.3%) agreed that is more important to take medications and stop smoking, than to undergo invasive treatment for their legs to prevent heart attacks, amputations, stroke, and death. Almost a quarter (23.8%) thought that with leg surgery or stents, no other treatments were needed to manage their PAD (Figure 1, Table S1). When comparing patient characteristics between those included in the knowledge and preferences sub study, against the remainder of the US PORTRAIT population, no meaningful differences were noted (all standardized mean differences 0.20 or smaller) (Table S2).

As for PAD treatment preferences, the majority (68.8%) preferred quick symptom relief, even if requiring invasive treatments with possible risks (Table S1). However, the majority (73.6%) also indicated that they want to avoid invasive treatments, if medications and exercise could relieve their symptoms. Amongst smokers, 22.1% preferred to continue smoking, even if this meant living shorter. A total of 73.3% was also prepared to engage in exercise therapy, in addition to their usual PAD care (Figure 1, Table S1).

Several treatment goals were identified, including “Avoid loss of toes or legs”, “Decreased risk of heart attack or stroke”, “Long-lasting treatment benefit”, “Living longer”, “Improved quality of life” and “Doing what the doctor thinks I should do”, which each had mean scores >9, with little variability across respondents as demonstrated by their interquartile ranges (IQR) and standard deviations (Table 2, Table S1). Treatment goals with lower perceived value and wider variability included “Avoiding a procedure or surgery”, “Quick pain relief”, “How quickly I can return to work”, and “Cost of treatment”, indicating more disparate ratings across respondents (Standard Deviations Ranging from 2.76–3.45; Table 2, Table S1).

Table 2.

Overview of PAD Treatment Goal Ratings. Means, standard deviations, medians, and interquartile range are depicted.

Treatment Goal	Mean	Standard Deviation	Median	Interquartile Range
Avoid Loss of Toes or Legs	9.76	1.21	10	10.00–10.00
Decreased Risk of Heart Attack or Stroke	9.58	1.44	10	10.00–10.00
Long-Lasting Treatment Benefit	9.18	2.00	10	10.00–10.00
Living Longer	9.17	1.84	10	10.00–10.00
Improved Quality of Life	9.16	1.65	10	9.00–10.00
Doing What the Doctor Thinks I Should Do	9.14	1.83	10	9.00–10.00
Avoiding Procedure or Surgery	8.1	2.93	10	7.00–10.00
Quick Pain Relief	7.83	2.76	9	6.00–10.00
How Quick I Can Return to Work	7.47	3.45	10	5.00–10.00
Cost of Treatment	6.46	3.58	8	3.50–10.00

When asking patients to choose the 5 most important PAD treatment goals, the top goal was improved quality of life (31.3%), followed by living longer (20.5%) and avoidance loss of toes or legs; decreased risk of heart attack or stroke (10.7%) (Figure 2, Table S1). Treatment goals identified beyond those specified included “being present for family” or “no concern” for treatment goals.

Figure 2.

Percentage of Most Frequently Named Important Peripheral Artery Disease Treatment Goals.

A small proportion received invasive treatment (endovascular or surgical revascularization) as their primary treatment strategy (19%, n=54) (Table 1). Those who received early invasive treatment were more likely to be female, White, and less likely to have a history of stroke or transient ischemic attack. Those who underwent invasive treatment vs. those who did not were more likely to believe that there was more than one way to treat their pain, that medications alone may relieve leg pain, that with surgery or stents no other treatment will be needed to manage their PAD; they also valued quick symptom relief vs. upfront risk more often, were less likely to avoid invasive treatment (vs. medications or exercise), and had higher importance scores for the following outcomes: avoiding loss of toes or legs, long lasting treatment benefit, and quick return to work (Table S3a–b).

DISCUSSION

As a foundation for improving shared decision-making in patients with PAD experiencing claudication symptoms, it is important to assess patients’ current understanding in routine clinical practice, their exposure to shared decision making and their treatment priorities. In our study, we identified substantial gaps in PAD knowledge among patients who were diagnosed and treated at vascular specialty clinics for their PAD. While most people understood that PAD is a chronic disease that needs to be managed for the rest of their lives, only half did not know that there are multiple options to manage their PAD symptoms, and fewer than half were offered multiple options. The role of cardiovascular risk management vs. the effects of invasive treatment for managing PAD was not clear to patients, as 1 in 5 thought that with invasive treatment, no other PAD treatment was needed. As for PAD treatment goals, improving their quality of life was most important, followed by avoiding amputations, death, stroke, and heart attacks. Collectively, these findings underscore the opportunity to further educate patients about PAD and its treatment and underscore the need to better clarify their treatment goals so that optimal treatments can be offered and discussed.

This study extends the current understanding of patients’ PAD knowledge and preferences. Previously, a general awareness survey around PAD documented gaps in PAD awareness among the public and amongst providers, and more recently, an overall lack of PAD disease identification was noted amongst patients with vascular complications.^10,16 Our study expands this prior work by showing that even amongst those having undergone a year of treatment for their PAD that opportunities exist for additional education and better clarification around the goals and roles of different therapeutic approaches. Our work complements prior work on preferences for interventions and trade-offs for amputation risk, as well as overall work exploring shared decision making preferences in vascular diseases, and the overall unawareness for the condition of PAD.^17–20 Understanding which goals are almost universal to patients navigating PAD vs. those that are more susceptible to individual variability can be helpful in creating shared decision-making tools to further improve the patient-centeredness of care. While shared decision aids for PAD are emerging, they will likely require further adaptation, efficacy testing, and dissemination as new insights emerge as to how offer educational materials and preferences elicitation in a more patient-centered way.⁷ In the same fashion, supporting shared decision efforts for more advanced lower extremity PAD, critical limb ischemia, will require dedicated of comparative effectiveness evidence base building, staged work with patient and provider stakeholders,^21,22 to elicit the trade-offs of treatment approaches. These efforts may be spurred by emerging comparative effectiveness research comparing surgical vs. endovascular approaches for critical limb ischemia.^23,24

Specifically to the preferences elicitation as it relates to the entire spectrum of PAD treatment goals, the following patterns of valuation emerged. We observed that almost all patients with symptomatic PAD involving claudication symptoms universally valued avoiding clinical events including amputation of toes and legs, death, stroke, or a heart attack, and improving their quality of life, which reinforce the need to value these endpoints in creating decision aids and as outcomes in emerging PAD trials. When asked to choose a top priority for their PAD treatment outcomes, more than a third chose improving quality of life as their most important goal, over avoiding clinical events, underscoring the utmost importance for this endpoint both in prioritizing clinical trial endpoints, as well as in prioritizing PAD treatment goals. More variability was observed for treatment goals related to work return, avoiding cost, quick pain relief, and avoiding surgery. Especially amongst those who had received invasive treatment vs. those who did not as their primary PAD symptom management strategy, the goals of quick pain relief and return to work were more valued. This emphasizes the importance of initiating a dialogue with patients who have PAD and are experiencing claudication about their individual preferences and characteristics, such as age, socio-economic status, and past medical history, as these factors can significantly influence their values and priorities. Only 20% of patients believe additional treatment is necessary after invasive treatment. Lifestyle-limiting claudication should be considered when evaluating treatment options. Patients who smoke and opt for revascularization procedures should be informed of the increased risk of reduced patency and amputation and offered support for smoking cessation. Less than half of the patients were presented with multiple options to manage their PAD symptoms, likely due to the lack of shared decision tools in claudication. Treatment variability may depend on the setting, but medical management should be prioritized, and patient education and shared decision-making promoted for informed treatment choices. Finally, patients with symptomatic PAD involving claudication valued the doctor’s treatment recommendation greatly, which does not necessarily have to contradict with the fact that patients want to play an active role in their decision-making process, as previously over 70% of patients with PAD indicated they wanted an active, shared role.⁹

Our study should be interpreted in the context of the following potential limitations. Due to the select sites that participated in the study, generalizability of the findings to other settings needs to be further established. The study participants had symptomatic PAD with claudication, and their perspectives may not be generalizable to patients with more severe forms of PAD like critical limb ischemia. It is also likely that the estimates of patients’ knowledge are greater in this context than in non-specialty clinics, given the focus of these clinics on patients’ PAD. Furthermore, patients with PAD and claudication were surveyed one year following their PAD diagnosis and treatment, which may have made them more informed about the PAD management options, as opposed to patients who are early into the diagnostic process. Future studies will need to evaluate both knowledge and preferences at the time of evaluation and follow-up to understand how they may evolve over time. As a follow up to our work, variations by demographic profiles will need to further be explored as preferences may differ as a function of patients’ background. In addition, while patients prioritized improvement of quality of life as an important treatment goal, it is unclear which aspects of their quality of life they valued the most. Lastly, preferences may also change over time, and longitudinal data on PAD treatment preferences are needed as they continue to manage their chronic disease.

In conclusion, we identified substantial, addressable knowledge gaps in patients with symptomatic PAD involving claudication who were treated in vascular specialty clinics. Moreover, we identified key PAD treatment preferences that can further inform shared decision-making frameworks for patients with symptomatic PAD. In an era of value-based PAD care, addressing PAD related health literacy and tailoring patient preferences to evidence-based PAD treatment options will be key to increase the quality of decision-making, work as active partners, both patients and the PAD care team, to optimize subsequent outcomes.

CLINICAL PERSPECTIVE.

What is new?

• As patients with symptomatic peripheral artery disease (PAD), i.e., claudication, make decisions about their treatment, almost all agree on improving their quality of life as the most important treatment goal. While everyone agrees on the importance of avoiding a stroke, heart attack or death, considering risks and benefits of invasive procedures for symptom management is much more individual and impacted by risk aversion and the importance of rapid symptom relief.

• Variability in knowledge about risks and benefits on the availability of PAD treatments for risk and symptom management is apparent in patients with PAD.

What are the clinical implications?

• Active discussions exploring knowledge and expectations about treatment goals for symptomatic PAD are important and key elements of shared decision making. Our study highlights gaps and variability in expectations that clinicians may want to further emphasize in their discussions with patients.

NON-STANDARD ABBREVIATIONS AND ACRONYMS

PAD

peripheral artery disease

Data Availability:

The data of this study are available from the corresponding author upon reasonable request.