Quality of Life in Individuals With Peripheral Arterial Disease Who Underwent Toe Amputations: A Descriptive, Cross-sectional Study

Studies have shown above- or below-the-knee amputation has a profound impact on physical, mental, and emotional health; the impact of having a toe(s) amputated is unknown. PURPOSE: This descriptive research study measured health-related quality of life (HRQoL) using the Vascular Quality-of-Life Questionnaire-6 (VascuQol-6) among persons with peripheral arterial disease (PAD) who had undergone toe amputations. METHODS: A list of 127 patients discharged from the hospital in 2016 with a diagnosis of PAD and toe amputation was provided to the investigator. The independent variables of age (subsequently divided into groups of persons <65 and ≥65 years of age), gender, race, diabetes mellitus, and time of PAD diagnosis (within the year or 2 to 7 years before 2016) were abstracted from the patient charts. A letter was mailed to potential participants that explained the study and the VascuQol-6 tool, along with a prepaid envelope to return the completed tool. The VascuQol-6 tool is a valid and reliable instrument for assessing HRQoL that covered the different aspects of quality of life (QoL) affected by PAD. The tool contains six 4-point Likert scale questions about activity, symptoms, pain, emotional status, and social life, resulting in a total score between 6 and 24. Higher values indicate better perceived quality of life. Variables were analyzed using frequencies, percentages, means, and standard deviations, and a standard t test was used to compare interval scale items. Statistical significance was noted when P <.05. RESULTS: Thirty-eight (38) completed surveys were returned (30% completion rate). The mean total score was 15.5 ± 3.93 (range 7–24), and the mean overall score of the 6 items was 2.66 ± 0.90 (range 1–4). In addition to a low overall QoL score, the data showed QoL was negatively affected in every area assessed, but some participants were strongly affected whereas others were not affected at all. No significant differences in QoL scores were noted concerning age groups, gender, race, the presence of diabetes mellitus, or time since PAD diagnosis. CONCLUSION: In this study, patients with PAD and toe amputations had low QoL scores related to their disease. Additional research is needed to better understand HRQoL related to PAD to facilitate education of patients considering toe amputation.

Peripheral arterial disease (PAD) is a progressive atherosclerotic condition that affects >200 million people worldwide, including a substantial proportion of the elderly population.¹ PAD leads to arterial stenosis and occlusions in the major vessels supplying the lower extremities. The impaired blood flow can lead to gangrene, and amputation may follow. Major amputation includes amputations above or below the knee and transmetatarsal amputation of the foot; toe amputation is considered a minor amputation.² 

In 2005, 1.6 million persons in the United States were living with a major limb amputation.³ Of these individuals, 38% had an amputation secondary to PAD with a comorbid diagnosis of diabetes mellitus (DM).³ The number of toe amputations occurring each year in the US is unknown. Some international studies have reported declining rates of major amputations and increasing rates of minor amputations, a shift that may be due to improvements in preventive health care.⁴ 

Griffin et al⁵ define toe amputation as a minor surgical procedure; there is a paucity of data on the long-term outcomes of patients undergoing toe amputation. Their retrospective chart review⁵ of 63 patients undergoing toe amputations for vascular risk factors and comorbidities and the correlation of additional limb loss found 35 (55.6%) went on to have an additional amputation, including 22 major amputations (16 below-knee and 6 above-knee amputations) and 13 minor amputations; 43 patients (68.3%) had DM and 31 (49.2%) had 1 or more revascularization procedures. A significant correlation was noted between patients who did not have DM and additional limb loss (chi-squared = 4.31; P = .038); however, no other risk factor was identified that predicted the need for major amputation. The authors noted that at their facility it is standard practice for all patients with DM to be seen regularly in a multidisciplinary diabetic foot clinic, although this service was not available to patients with only the diagnosis of PAD.⁵

Research studies on health-related quality of life (HRQoL) after toe amputation with or without PAD have not been published. Evaluating HRQoL in individuals with PAD and toe amputations could lead to interventions tailored to address the specific HRQoL concerns of these individuals. Unfortunately, the number of items requiring a response in most HRQoL instruments makes their use in the clinical setting very time-consuming. The ideal HRQoL instrument should be valid and reliable, aimed at a seventh or eighth grade reading level, have a limited number of items, and be easy to complete.

In their effort to develop a disease-specific quality-of-life (QoL) tool for patients with PAD, Morgan et al⁶ describe the development and testing of a Vascular Quality of Life (VascuQoL) instrument for patients with PAD. The first phase consisted of item generation and pretesting in patients with PAD. Items with the highest clinical impact factor (ie, ability to walk, pain in legs/feet, worry about poor circulation in legs, ability to participate in social activities) were used to formulate a 25-item questionnaire that was pretested in 20 patients with PAD. The 25 items were divided into 5 subscales: pain (4 items), symptoms (4 items), activities (8 items), social (2 items), and emotional (7 items), with each question measured on a 7-point Likert scale ranging from 1 (worst HRQoL) to 7 (best HRQoL); total scores range from 25 to 175 and higher scores indicate better QoL. Reliability, internal consistency, responsiveness, and validity of the questionnaire were tested on 39 patients with PAD at 2 separate clinic visits 4 weeks apart. Test-retest scores showed a reliability of r >0.90. Each item had internal consistency (Cronbach α = .7-.9). The questionnaire showed face and construct validity.

Nordanstig et al⁷ developed a shorter version of the VascuQoL-25 — the VascuQol-6 — to make it a more practical option for use in vascular clinics. They recruited 200 PAD patients from 2 university hospitals. All patients completed the VascuQoL-25 when initially evaluated for PAD treatment and 127 completed it 6 months later after receiving treatment for PAD. The VascuQoL-25 was reduced to 6 questions based on patient interviews and psychometric testing; this new version (the VascuQol-6) was tested using item-response theory, exploring structure, precision, item fit, and targeting. The correlation between the VascuQoL-25 and the VascuQoL-6 was r = 0.88 before intervention and r = 0.96 after intervention; the difference was r = 0.91 (P <.001). The Cronbach α for the VascuQoL-6 was .85 before and .94 after intervention. Cognitive interviews of 15 patients indicated they considered all 6 items to be relevant and understandable. Rasch analysis⁷ was used to reduce the number options for each question from 7 (VascuQoL-25) to 4 (VascuQoL-6).

Kumlien et al⁸ administered the VascuQol-6 and the Short Form Health Survey-36 (SF-36) to 200 patients treated at 2 vascular centers in Sweden to explore both the validity and the reliability of the VascuQol-6 in the target population. Among the 200 patients, 150 also received a second VascuQol-6 for a test-retest assessment. In addition, a sample of 22 PAD patients consented to participate in cognitive interviews. The questionnaire data were tested by both Rasch analysis and traditional psychometric methods. Validity and reliability of the VascuQol-6 was high and a good fit to the Rasch model. Internal consistency and significant correlations between comparable dimensions in SF-36 were demonstrated. In the test-retest analysis, the percentage agreement was somewhat poor (<70%) among the 6 items. However, no systematic disagreements between the 2 assessments were noted in any of the 6 items, and the test-retest assessment for the VascuQol-6 sum score showed an acceptable intraclass correlation coefficient (0.86).  All items in the VascuQol-6 were considered understandable and relevant by the interviewed patients. The VascuQol-6 also has been tested for validity and reliability in additional countries such as Norway⁹ and Brazil.¹⁰ 

The purpose of this descriptive, cross-sectional study was to evaluate HRQoL issues using the VascuQol-6 tool among patients with PAD who had undergone toe amputations.

Participants and setting. The study site was a 600-bed, Level-1 trauma center serving central and western Virginia. The University of Virginia Health System Institutional Review Board (IRB) approved the study and determined written consent was inherent in patients returning the mailed questionnaires. IRB eligibility requirements stipulated participants must be at least 18 years of age, have a diagnosis of PAD, have undergone a toe amputation, and able to read English well enough to complete the VascuQol-6 tool.  

Hospital records were used to determine patients discharged from the facility in 2016 with a primary International Classification of Diseases, Tenth Revision) code for PAD (170.2) and toe amputation(s) (Z89.4). A list of 127 patients with these codes was provided to the primary investigator; all potential participants were mailed the questionnaire. The independent variables of age (subsequently divided into 2 groups: <65 or ≥65 years), gender, race, DM, and time of PAD diagnosis (within the year or 2 to 7 years before 2016) were selected for assessment to determine differences regarding their affect on quality of life. 

Instrument. The VascuQol-6 tool is a valid and reliable HRQoL assessment tool that addresses different aspects of QoL affected by PAD. The tool contains 6 questions on a 4-point Likert scale. Each question is scored from 1 to 4, where 1 = a negative  and 4 = a positive response. The total score is achieved by summarizing the score on each question, resulting in a total score between 6 and 24. Higher values indicate better perceived QoL. 

Two (2) items in the VascuQol-6 tool address activity related to PAD: 1) Because of the poor circulation in my legs, the range of activities that I would have liked to do has been severely limited, very limited, very slightly limited, or not limited at all; and 2) My legs have felt tired or weak all of the time, some of the time, a little of the time, or none of the time, limiting activity. One (1) item addresses pain: When I have had pain in the leg (or foot), it has given me a great deal of discomfort, a moderate amount of discomfort, very little discomfort, or no discomfort. One (1) item deals with emotional distress: I have been concerned about having poor circulation in my legs all of the time, some of the time, a little of the time, or none of the time. One (1) item concerns social activity: Because of the poor circulation in my legs, my ability to participate in social activities has been totally limited, very limited, a little limited, or not at all limited. 

In addition, the 127 potential participants were mailed an introductory letter from the principal investigator explaining the study along with instructions for completing the VascuQol-6 questionnaire and mailing it back to the investigator in the prepaid return envelope within 6 weeks. Data related to the study were kept in a locked file cabinet. Data from the questionnaires were entered in an Excel spreadsheet, de-identified, and analyzed by a statistician using SPSS Statistics for Windows, version 20 (IBM Corporation, Armonk, NY). Descriptive statistics (frequencies, percentages, mean, and standard deviations) were used to describe the study sample, and interval scale items were analyzed using the standard t test. Statistical significance was achieved when P <.05.

Among the 38 study participants who returned the survey (response rate 30%; 25 men, 13 women; mean age 62 ± 12.69 [range 36–88] years) (see Table 1), men scored slightly higher (perceived better quality of life) than women (mean scores 2.77 ± 0.95 vs. 2.55 ± 0.82, respectively). However, when considering emotional concerns (mean scores 2.62 ± 1.33 vs. 2.56 ± 1.19, respectively) and social activities (mean scores 3.08 ± 0.86 vs. 2.96 ± 1.117, respectively), women’s mean scores were slightly higher (perceived better quality of life) than men. None of the differences was significant (see Table 2). 

The t tests comparing item means and overall score mean between persons <65 and ≥65 years of age showed mean scores of the older group (n = 18) were slightly higher on the VascuQol-6 tool than the younger group (n = 20) (2.72 ± 0.82 vs. 2.60 ± 0.99, respectively), except for item 5 concerning social activities where the younger group’s mean scores were slightly higher than the older group (3.05 ± 11.0 vs. 2.94 ± 1.06, respectively). None of the differences was significant (see Table 3).

In terms of race, 22 patients (57.9%) were white, 15 (39.5%) were black, and 1 (2.6%) was Asian (see Table 4). Mean scores of black persons ranged slightl higher than white persons (2.76 ± 0.96 vs. 2.60 ± 0.89, respectively), except for the question that asked about activities (white persons scored 2.68 ±0.99 vs. 2.40 ± 1.06 for blacks). None of the differences was significant. The single Asian participant was dropped from the race table only.

Thirty (30, 78.9%) persons had DM and 8 (21.1%) did not (see Table 5). Mean scores of persons without DM were slightly higher than those with the disease (2.90 ± 0.68 vs. 2.59 ± 0.95, respectively) except for the item that addressed symptoms (weakness); persons with DM had slightly higher mean scores (2.63 ± 1.16 vs. 2.38 ± 1.06, respectively). None of the differences was significant. 

Six (6, 15.8%) patients were diagnosed with PAD within the year of 2016 (see Table 6);  32 (84.2%) were diagnosed with PAD between 2 to 7 years before 2016. The t tests comparing the item means and the overall score mean between the 2 groups found, on all items, persons diagnosed with PAD in 2016 had slightly higher mean scores than those diagnosed earlier (2.94 ± 0.88 vs. 2.60 ± 0.91, respectively), although none of the differences was statistically significant. 

Among the 38 participants, the mean total score for the 6 items was 15.5 ± 3.93 (range 7–24), showing patients in this study had QoL issues. The overall score of the mean of the 6 items was 2.66 ± 0.90, showing participants were strongly affected in every area of QoL, although some were not affected at all (see Table 7). The independent variable scores of age, gender, race, DM, and PAD were not significantly different.  

Nordanstig et al⁷ developed a shorter version of the VascuQoL-25, the VascuQol-6, to make it a more practical option for use in vascular clinics. Only 1 clinical study analyzed the total scores of the VascuQol-6; in that study, Corriere et al¹¹ found that among the 32 participants (mean age 63 ± 10 years; 72% men; 63% white), mean VascuQol-6 score was 11.6 ± 4.2, and HRQoL was lower in patients with more previous vascular interventions. No association between comorbidity such as DM and HRQoL was identified. 

In the current study, 38 participants with demographics similar to the Corriere et al¹¹ study included 66% men and 34% women with a mean age of 62 years. Thirty-two (32, 84.2%) were diagnosed with PAD between 2 to 7 years before 2016, but the number of vascular interventions was unknown. Total scores for VascuQol-6 in the current study ranged from 7 to 24 with a mean of 15.5 (SD 3.93), which is a slightly better average QoL score than that reported in the Corriere et al¹¹ study that found VascuQol-6 scores were lower in patients with more vascular interventions. The current study looked at time since PAD diagnosis and not the number of vascular interventions. 

Research on PAD has traditionally focused on medical outcomes regarding therapies to treat the disease. Steunenberg et al¹² conducted a systematic review to explore the best clinical treatment decisions to increase HRQoL in patients with critical limb ischemia, a severe form of PAD characterized by ischemic pain and wounds. The authors found no studies that examined HRQoL of patients undergoing major amputation as the only treatment. No studies looked at minor amputation (toe amputation), underscoring the importance of the current study describing HRQoL in patients with PAD who underwent toe amputations.  

The authors presumed individuals completing the questionnaire understood the questions. Although higher response rates can reduce the risk of nonresponse bias, other factors, such as the nature of the population being studied and survey administration, are more often the source of such bias.¹³ PAD populations are historically difficult to study, with large numbers of patients often lost to follow-up or dying in longitudinal studies, leading to incomplete data sets.¹⁴ The response rate for this mailed survey (30%) might have been higher if an incentive such as a gift card was provided for completing the survey.  The sample size was small, site-specific, and assessed HRQoL at a single point in time, which may limit the ability to generalize results. 

This descriptive research study measured HRQoL using the VascuQol-6 among 38 persons with PAD who had undergone toe amputations. Total scores ranged from 7 to 24 with a mean of 16 (SD 5.39). Because a QoL score of 24 suggests no or minimal QoL issues, these patients were shown to have QoL issues related to their situation. However, the independent variables of age, gender, race, and DM were not statistically significant factors affecting QoL. Additional studies that comprise a larger sample and examine patients with PAD with toe amputations at different time frames such as preoperatively and at 1 month, 3 months, and 6 months post toe amputation are warranted to determine whether QoL improves over time. It also would be helpful to examine the number of vascular interventions before and after undergoing toe amputation to better illuminate HRQoL issues faced by these patients and help clinicians begin to address the specific HRQoL concerns of PAD patients before they undergo the toe amputation. 

Dr. Ratliff is a Nurse Practitioner/Clinical Associate Professor; Dr. Strider is a Nurse Practitioner/Clinical Assistant Professor, Division of Vascular and Endovascular Surgery, Department of Surgery; and Dr.  Rovnyak is a nurse scientist, School of Nursing, University of Virginia Health System, Charlottesville, VA. 

The Beta Kappa Chapter of Sigma Theta Tau, the Nursing Honor Society, provided a $500 educational grant for this study.

Please address correspondence to: Catherine R. Ratliff, PhD, GNP-BC, CWOCN, CFCN, Division Vascular and Endovascular Surgery, Department of Surgery, University of Virginia Health System, Box 801351, 409 Lane Road, Charlottesville, VA 2290; email: Crr9m@virginia.edu.