Psychosocial and socioeconomic factors are most predictive of health status in patients with claudication.

BACKGROUND: As a key treatment goal for patients with symptomatic peripheral artery disease (PAD), improving health status has also become an important end point for clinical trials and performance-based care. An understanding of patient factors associated with 1-year PAD health status is lacking in patients with PAD. METHODS: The health status of 1073 consecutive patients with symptomatic PAD in the international multicenter PORTRAIT (Patient-Centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories) registry was measured at baseline and 1 year with the Peripheral Artery Questionnaire (PAQ). The association of 47 patient characteristics with 1-year PAQ scores was assessed using a random forest algorithm. Variables of clinical significance were retained and included in a hierarchical multivariable linear regression model predicting 1-year PAQ summary scores. RESULTS: The mean age of patients was 67.7 ± 9.3 years, and 37% were female. Variables with the highest importance ranking in predicting 1-year PAQ summary score were baseline PAQ summary score, Patient Health Questionnaire-8 depression score, Generalized Anxiety Disorder-2 anxiety score, new onset symptom presentation, insurance status, current or prior diagnosis of depression, low social support, initial invasive treatment, duration of symptoms, and race. The addition of 19 clinical variables in an extended model marginally improved the explained variance in 1-year health status (from R2 0.312 to 0.335). CONCLUSIONS: Patients' 1-year PAD-specific health status, as measured by the PAQ, can be predicted from 10 mostly psychosocial and socioeconomic patient characteristics including depression, anxiety, insurance status, social support, and symptoms. These characteristics should be validated and tested in other PAD cohorts so that this model can inform risk adjustment and prediction of PAD health status in comparative effectiveness research and performance-based care.

Assessment of behavioral determinants influencing success of supervised exercise therapy in patients with intermittent claudication: A cross sectional survey.

BACKGROUND: Supervised exercise therapy is the first step in treatment of intermittent claudication. However, adherence to supervised exercise therapy is low. Limited access and reimbursement issues are known reasons, though lack of motivation is often leading. Behavioral determinants influencing motivation and thus adherence to supervised exercise therapy remain to be investigated. In this study we sought to determine which behavioral determinants would be of influence on the long-term adherence of supervised exercise therapy. METHODS: 200 patients, newly diagnosed with peripheral arterial disease Rutherford classification II-III, were sent a questionnaire to assess motivation and behavior with regard to supervised exercise therapy. The questionnaire was constructed using the I-CHANGE model for explaining motivational and behavioral change. Baseline characteristics were acquired from medical records. Alpha Cronbach's was calculated to test reliability of the questionnaire. RESULTS: 108 (54%) patients returned their questionnaire. A total of 79% patients followed supervised exercise therapy. Patients who increased their walking distance after supervised exercise therapy have significantly greater knowledge (p = 0.05), positive attitude (p = 0.03) and lower negative attitude (p = 0.01). Patients with a higher self-efficacy remained significantly more active after participating in supervised exercise therapy (p = 0.05). CONCLUSION: Increasing the determinants knowledge, attitude and self-efficacy will improve adherence to supervised exercise therapy and result in delayed claudication onset time.

Delayed gratification and adherence to exercise among patients with claudication.

Few studies have explicitly identified factors that explain an individual's willingness to engage in community-based exercise for claudication. Identifying the unique characteristics of those inclined toward physical activity would inform interventions that encourage walking. We examined the utility of behavioral economics-related concepts in understanding walking among Veterans with claudication. Patients who received care at the Michael E. DeBakey Veterans Affairs Medical Center in Houston, Texas, were surveyed on symptom severity, behavioral economics, stress, and depression. The primary outcome was a binary variable measuring current walking for exercise and defined as walking for at least 30 minutes every day. Multivariable logistic regression models were used to identify variables, both clinically and statistically significant, at a p-value < 0.05. Between April 2017 and March 2018, we received 148 (30%) responses. A total of 35% (n = 51) of respondents indicated that they walked recreationally for exercise compared to 65% (n = 94) who did not. Characteristics that were significantly associated with walking included regularly saving money (adjusted odds ratio (aOR) = 10.7, p = 0.001), seeking complex problem-solving (aOR = 0.12, p = 0.002), and severe symptoms (aOR = 0.24, p = 0.017). Individuals describing a preference for the future rather than immediate benefit also reported currently walking for exercise. Defining the characteristics of those who exercise may help inform strategies designed to increase walking among those who do not adhere to recommendations.

The role of psychopathology in perceiving, reporting and treating intermittent claudication: a systematic review.

INTRODUCTION: The aim of this systematic review is to investigate the association between mental health and intermittent claudication (IC) perception, reporting and treatment in subjects with peripheral artery disease (PAD). EVIDENCE ACQUISITION: Literature searches of experimental and observational studies published until February 1st, 2016 were conducted using the following electronic databases: Medline/PubMed and Embase. The selection criteria for the studies included a population of patients diagnosed with peripheral artery disease who reported symptoms of intermittent claudication and were assessed for any psychopathological states (depression, anxiety, mood and personality disorders), which in turn were analyzed with regard to the following: IC severity, symptom perception and reporting, patients' quality of life, treatment compliance and its effectiveness. The risk of bias was assessed using Cochrane Collaboration's tool and the Newcastle Ottawa Scales. The strength of recommendations was graded according to GRADE system. EVIDENCE SYNTHESIS: The literature search identified 1598 citations, of which 13 studies with varying risk of bias were included in the review. Depression, anxiety, and personality types were described in more than 800 patients with peripheral arterial disease who suffered from intermittent claudication. With regard to IC perception and reporting, individuals with higher levels of depression had lower levels of pain acceptance, were more dissatisfied with their function and control over function and had a poorer quality of life. In the case of the type D personality, the results were not consistent. Studies assessing the influence of psychopathology on IC severity and treatment also showed discrepant results. Some studies indicated no differences between type D and non-type D patients with regard to the Ankle Brachial Index as well as pain free (PFWD) and maximal walking distances (MWD). On the other hand, others revealed that type D and depressed patients terminated 6MWT prematurely due to the onset of symptoms and experienced a greater annual decline in 6-minute walk distance, fast walking velocity and short physical performance battery. With regard to treatment adherence, patients with no mental problems made the best recoveries. Hostility, aggressiveness and affect-liability were the greatest obstacles to compliance. CONCLUSIONS: Mental disorders might influence the way in which the symptoms of the disease are reported, coped with, and treated. However, the results of the review preclude recommending a routine psychological examination as one of basic diagnostic procedures in patients with peripheral artery disease suffering from IC.

PORTRAIT (Patient-Centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories): Overview of Design and Rationale of an International Prospective Peripheral Arterial Disease Study.

BACKGROUND: Health status outcomes, including symptoms, functional status, and quality of life, are critically important outcomes from patients' perspectives. The PORTRAIT study (Patient-Centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories) was designed to prospectively define health status outcomes and examine associations between patients' characteristics and care to these outcomes among those presenting with new-onset or worsened claudication. METHODS AND RESULTS: PORTRAIT screened 3637 patients with an abnormal ankle-brachial index and new, or worsened, claudication symptoms from 16 peripheral arterial disease (PAD) specialty clinics in the United States, the Netherlands, and Australia between June 2, 2011, and December 3, 2015. Of the 1608 eligible patients, 1275 (79%) were enrolled. Before treatment, patients were interviewed to obtain their demographics, PAD symptoms and health status, psychosocial characteristics, preferences for shared decision-making, socioeconomic, and cardiovascular risk factors. Patients' medical history, comorbidities, and PAD diagnostic information were abstracted from patients' medical records. Serial information about patients' health status, psychosocial, and lifestyle factors was collected at 3, 6, and 12 months by a core laboratory. Follow-up rates ranged from 84.2% to 91%. Clinical follow-up for PAD-related hospitalizations and major cardiovascular events is ongoing. CONCLUSIONS: PORTRAIT systematically collected serial PAD-specific health status data as a foundation for risk stratification, comparative effectiveness studies, and clinicians' adherence to quality-based performance measures. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01419080.

Identifying content gaps in health status measures for intermittent claudication using the International Classification of Functioning, Disability and Health.

OBJECTIVE: The Walking Impairment Questionnaire (WIQ) and Intermittent Claudication Questionnaire (ICQ) are commonly used patient-reported functional outcome measures for intermittent claudication, but their functional representation has not been characterized. The World Health Organization's International Classification of Functioning, Disability and Health (ICF) framework comprehensively describes health-related function and has been used to evaluate health status and quality of life (QOL) measures. We applied a content analysis technique commonly used in functional rehabilitation research to evaluate ICF domains represented by WIQ and ICQ to characterize their health status and functional representation. METHODS: The overall perspective of each question was assigned as health status-function, health status-disability, Environment-facilitator, Environment-barrier, or QOL. All meaningful concepts in each question were identified and linked to the most appropriate and precise ICF code from the hierarchy of component, chapter, or category using the validated technique. A 20% random sample of questions was secondarily coded with disagreements resolved by discussion. RESULTS: Codability was agreed upon for 87% of questions; agreement was 100% on component and chapter and 88% on category. WIQ contains 18 concepts among 14 questions (1.3 concepts per question); all questions are from the health status-disability perspective. All WIQ concepts are from the "Activities/Participation-d" ICF component, "Mobility-d4" chapter. "Walking long distances" (d4501, >1 km) is omitted. ICQ contains 37 codable concepts among 16 questions (2.3 concepts per question). Thirteen questions are from health status-disability perspective, three from QOL. Sox of the nine chapters of the "Activities/Participation-d" ICF component are represented by 20 of 37 concepts; 11 of 20 in the "Mobility-d4" chapter. The other "Activities/Participation-d" chapters and categories in ICQ are "Learning/applying knowledge" ("thinking-d163"), "General tasks/demands" ("carrying out daily routine-d230"), "Domestic life" ("shopping-d6200," "doing housework-d640"), "Major life areas" ("Maintaining a job-d8451"), and "Community life" ("socializing-d9205," "hobbies-d9204"). "Body Functions-b" ICF component is represented 11 times, covering pain, numbness, emotion, mood, and cardiovascular functions. "Body Structures-s" is represented three times as lower extremity. Neither WIQ nor ICQ specifically addresses "Walking on different surfaces," (64,502) "Walking around obstacles" (d4503), or "Moving around using equipment" (d465), which includes assistive devices. Walking on an incline is not addressed in WIQ, ICQ, or the ICF. CONCLUSIONS: Applying this ICF-based content assessment methodology to patient-reported vascular disease outcome measures is feasible, representing a novel method of assessing such instruments. WIQ's scope is limited; it does not address functional capacity and covers only health status pertaining to walking disability. The ICQ is more inclusive, but concept density may obscure meaning. Neither instrument is functionally comprehensive and both have significant omissions that should be considered for inclusion.

Assessment of Minimum Important Difference and Substantial Clinical Benefit with the Vascular Quality of Life Questionnaire-6 when Evaluating Revascularisation Procedures in Peripheral Arterial Disease.

OBJECTIVES: Patient reported outcomes are increasingly used to assess outcomes after peripheral arterial disease (PAD) interventions. VascuQoL-6 (VQ-6) is a PAD specific health-related quality of life (HRQoL) instrument for routine clinical practice and clinical research. This study assessed the minimum important difference for the VQ-6 and determined thresholds for the minimum important difference and substantial clinical benefit following PAD revascularisation. MATERIALS AND METHODS: This was a population-based observational cohort study. VQ-6 data from the Swedvasc Registry (January 2014 to September 2016) was analysed for revascularised PAD patients. The minimum important difference was determined using a combination of a distribution based and an anchor-based method, while receiver operating characteristic curve analysis (ROC) was used to determine optimal thresholds for a substantial clinical benefit following revascularisation. RESULTS: A total of 3194 revascularised PAD patients with complete VQ-6 baseline recordings (intermittent claudication (IC) n = 1622 and critical limb ischaemia (CLI) n = 1572) were studied, of which 2996 had complete VQ-6 recordings 30 days and 1092 a year after the vascular intervention. The minimum important difference 1 year after revascularisation for IC patients ranged from 1.7 to 2.2 scale steps, depending on the method of analysis. Among CLI patients, the minimum important difference after 1 year was 1.9 scale steps. ROC analyses demonstrated that the VQ-6 discriminative properties for a substantial clinical benefit was excellent for IC patients (area under curve (AUC) 0.87, sensitivity 0.81, specificity 0.76) and acceptable in CLI (AUC 0.736, sensitivity 0.63, specificity 0.72). An optimal VQ-6 threshold for a substantial clinical benefit was determined at 3.5 scale steps among IC patients and 4.5 in CLI patients. CONCLUSIONS: The suggested thresholds for minimum important difference and substantial clinical benefit could be used when evaluating VQ-6 outcomes following different interventions in PAD and in the design of clinical trials.

The influence of pain-related beliefs on physical activity and health attitudes in patients with claudication: A pilot study.

We examined how pain beliefs are related to symptom severity, expectations of risk/benefits, and baseline physical activity among claudicants. Eligible patients at the Michael E DeBakey Veterans Affairs Medical Center were administered questionnaires that measured: fear-avoidance beliefs (Fear-Avoidance Beliefs Questionnaire [FABQ]), walking impairment, baseline physical activity, claudication type, and risk/benefit attitudes. Among 20 participants, the median age was 69 years (IQR: 66-75). In our efforts to understand how fear-avoidance beliefs influenced physical activity among people with claudication, we found that 12 out of 19 participants (63%) thought that the primary etiology of their pain was walking, while 18 (out of 20) (90%) people thought that walking would exacerbate their leg symptoms - suggesting that there was some confusion regarding the effects of walking on claudication. Those who expected that walking would benefit their symptoms more than surgery reported fewer fear-avoidance beliefs ( p=0.01), but those who believed that walking would make their leg pain worse expected greater benefit from surgery ( p=0.02). As symptom severity increased, fear-avoidance beliefs also increased ( p=0.001). The association between symptom severity and fear-avoidance beliefs indicates that as pain or impairment increases, the likelihood of avoiding behaviors that are thought to cause pain might also increase. Accounting for pain-related beliefs when recommending physical activity for claudication should be considered.

Clinimetric Evaluation of the Vascular Quality of Life Questionnaire in Patients with Lower Limb Ischaemia.

OBJECTIVES: Although commonly used to measure health related quality of life in patients with lower limb ischaemia, the measurement properties of the VascuQol and its assumed underlying health dimensions have not been studied in depth. The objective of this study was therefore to evaluate aspects of reliability and validity of the Dutch version of the VascuQol in patients with intermittent claudication (IC) and critical limb ischaemia (CLI). METHODS: Two datasets containing 195 patients with IC and 150 patients with CLI were used. Face validity of the VascuQol was examined in interviews with patients and a survey among health professionals. Homogeneity and structural validity of the VascuQol were assessed using Cronbach's α coefficients and explanatory factor analysis. Furthermore, convergent validity and known group validity were assessed. RESULTS: During the face validity interviews, three items were indicated as less relevant. Homogeneity analysis showed that the α coefficient of the VascuQol was .93, while the symptoms and social domains had α coefficients below the threshold of .70. The original five domains of the VascuQol could not be reproduced. Instead, factor analysis yielded a three factor solution. Moderate correlations were found for the activities, social and emotional VascuQol domains and matching health domains of other patient reported outcome measures (PROMs). Lower convergent correlations were observed for the pain domain and the sumscore of the VascuQol. The VascuQol was able to distinguish between patients' level of HRQL in relation to their disease severity (IC versus CLI patients). CONCLUSIONS: There is room for improvement of the VascuQol questionnaire. Further clinimetric studies should be performed to strengthen clinically relevant findings based on this instrument.

Supervised exercise therapy: it does work, but how to set up a program?

Intermittent claudication (IC) is a manifestation of peripheral arterial disease. IC has a high prevalence in the older population, is closely associated with other expressions of atherosclerotic disease and often co-exists in multimorbid patients. Treatment of IC should address reduction of cardiovascular risk and improvement of functional capacity and health-related quality of life (QoL). As recommended by contemporary international guidelines, the first-line treatment includes supervised exercise therapy (SET). In several randomized controlled trials and systematic reviews, SET is compared with usual care, placebo, walking advice and endovascular revascularization. The evidence supporting the efficacy of SET programs to alleviate claudication symptoms is robust. SET improves walking distance and health-related QoL and appears to be the most cost-effective treatment for IC. Nevertheless, only few of all newly diagnosed IC patients worldwide receive this safe, efficient and structured treatment. Worldwide implementation of structured SET programs is seriously impeded by outdated arguments favoring an invasive intervention, absence of a network of specialized physical therapists providing standardized SET and lack of awareness and/or knowledge of the importance of SET by referring physicians. Besides, misguiding financial incentives and lack of reimbursement hamper actual use of SET programs. In the Netherlands, a national integrated care network (ClaudicatioNet) was launched in 2011 to combat treatment shortcomings and stimulate cohesion and collaboration between stakeholders. This care intervention has resulted in optimized quality of care for all patients with IC.

Revascularization of smokers with claudication is not predicted to limit quality of life despite a higher risk of late failure.

OBJECTIVE: Tobacco smoking after lower extremity revascularization for claudication has repeatedly been shown to increase the risk of adverse events, such that many vascular specialists consider that refusal to abstain from smoking constitutes a major contraindication to open surgical bypass or endovascular intervention. METHODS: A Markov decision analysis (DA) model was used to compare the options of direct revascularization vs medical therapy only in smokers with claudication. The primary outcome was calculated quality of life (cQoL), determined for each patient at follow-up based on the outcomes of the treatment received. Markov DA software was used to predict the QoL for each treatment option preoperatively based on smoking status. RESULTS: Among patients referred during a recent 64-month period with vasculogenic claudication, 94 were actively smoking compared with 217 who were not. The DA model predicted that if the patients who smoked were to discontinue smoking, the best therapy would be bypass surgery for 77% and endovascular intervention for 17%. However, despite at least doubling the risks with intervention in the patients who continue to smoke, the DA model still predicted that 78% and 9% would fare better with open surgical or endovascular intervention, respectively. Among actively smoking patients, open surgical (3%) or endovascular (4%) therapies were initially performed in few patients, whereas 93% were offered only medical therapy. Among initial nonsmokers, revascularization was performed by open (27%) or endovascular (42%) means. At 3 years, the median (interquartile range [IQR]) cQoL was lower in initial smokers than in nonsmokers (0.73 [IQR, 0.73-0.77] vs 0.82 [IQR, 0.75-0.86]; P < .0001), primarily because of a lack of revascularization for smokers. Among initial smokers who did undergo revascularization initially, because of progression of symptoms, or after smoking cessation, cQoL was similar to initial nonsmokers (0.77 [IQR, 0.73-0.84] vs 0.73 [IQR, 0.73-0.73]; P = .37). Although 26% of initial smokers had stopped by the time of their last follow-up, 10% of initially nonsmoking patients were smoking at follow-up. However, among all patients undergoing intervention, the cQoL of patients smoking at the time of last their follow-up was similar to nonsmokers (0.82 [IQR, 0.82-0.86] vs 0.83 [IQR, 0.73-0.86]; P = .99). CONCLUSIONS: Patients with claudication who smoke may be denied the symptom improvement associated with revascularization, yet recidivism for smoking also occurs among patients who have stopped smoking in order to receive revascularization. The strategy not to directly revascularize patients with claudication who continue to smoke does not appear to maximize patient midterm QoL.

Comparison of Use of Short Form-36 Domain Scores and Patient Responses for Derivation of Preference-Based SF6D Index to Calculate Quality-Adjusted Life Years in Patients with Intermittent Claudication.

BACKGROUND: The short form 36 (SF36) questionnaire is used for assessment of generic quality of life. Responses to the individual question in SF36 are also used for calculation of the SF6D index score. This score is used for calculation of quality adjusted-life years (QALYs) in economical analyses. As the individual patient questionnaires are not always available for performing systematic reviews and meta-analyses, a new formula has been developed for derivation of SF6D index score from the reported SF36-domain scores. This study aimed to evaluate the validity of this formula for use in patients with intermittent claudication. METHODS: A retrospective review of a prospectively collected database of a randomized controlled trial was performed. A total of 178 patients were recruited. Clinical indicators of ischemia were recorded. All patients completed SF36 questionnaires. Response and domain-based SF6D scores (R-SF6D and D-SF6D) and QALYs were calculated. Correlation and agreement analysis were performed. RESULTS: Response rate was 88% (n = 781) over a 1-year follow-up period. Domain-based SF6D score (mean, 0.684; standard deviation [SD] 0.110) was significantly higher (paired t-test, P = 0.001) than the response-based score (mean, 0.627; SD, 0.110) with a mean difference of 0.056 (95% confidence interval, 0.053-0.060). Mean QALY calculated using D-SF6D score (0.503; SD, 0.116) was also significantly higher than the QALY calculated from the R-SF6D score (0.467; SD, 0.121). Bland-Altman comparison showed strong agreement (limit of agreement -0.167 to 0.054) between the 2 methods with equal variances (Pitman's test, P = 0.629). D-SF6D scores showed stronger correlation with clinical indicators of ischemia (r = 0.246-0.602) compared with that of R-SF6D scores (r = 0.233-0.549). CONCLUSIONS: Domain-based estimation of SF6D score is a valid and reliable method with strong agreement to the gold standard response-based scores in claudicants. However, adjustments may be required in studies using a mixture of D-SF6D and R-SF6D scores for QALY calculation.

Assessing the quality of available patient reported outcome measures for intermittent claudication: a systematic review using the COSMIN checklist.

OBJECTIVE: The aim was to critically appraise, compare, and summarize the quality of the measurement properties of all available disease specific patient reported outcome measures (PROMs) on health related quality of life and functional status validated in patients with intermittent claudication (IC). METHODS: A systematic search was carried out in Embase and Medline (last search November 18, 2013). The quality of the identified studies was assessed per measurement property according to the COnsensus-based Standards for the selection of health Measurements Instruments (COSMIN) checklist. Data on the measurement properties were extracted to determine a level of evidence per measurement property per instrument. RESULTS: Forty three studies were found evaluating 10 health related quality of life and two functional status PROMs. Evidence for the existence of subscales (structural validity) and for internal consistency (interrelatedness of items within subscales) for PROMs was generally poor. Evidence for construct validity was limited. Accuracy and reproducibility of PROMs were often uncertain, since reliability studies were mostly performed in small patient samples. Responsiveness, or the ability of PROMs to detect change over time, was hardly ever studied. CONCLUSION: The quality of the validation of most disease specific PROMs for IC is alarming, hampering all conclusion based on these PROMs. Considering the results, the PAD quality of life questionnaire (PADQOL), Intermittent claudication questionnaire (ICQ) and the Vascular quality of life questionnaire (VascuQol) might be appropriate PROMs for health related quality of life, while the Walking impairment questionnaire (WIQ) and Estimate ambulation capacity by history questionnaire (EACH-Q) appear suitable PROMs for functional status. However, all PROMs require further validation studies to fill the gaps in their measurement properties. The shortcomings highlighted in this review should be taken into account when interpreting PROM results.

Vascular Quality of Life Questionnaire-6 facilitates health-related quality of life assessment in peripheral arterial disease.

BACKGROUND: Most commonly used outcome measures in peripheral arterial disease (PAD) provide scarce information about achieved patient benefit. Therefore, patient-reported outcome measures have become increasingly important as complementary outcome measures. The abundance of items in most health-related quality of life instruments makes everyday clinical use difficult. This study aimed to develop a short version of the 25-item Vascular Quality of Life Questionnaire (VascuQoL-25), a PAD-specific health-related quality of life instrument. METHODS: The study recruited 129 individuals with intermittent claudication and 71 with critical limb ischemia from two university hospitals. Participants were a mean age of 70 ± 9 years, and 57% were men. All patients completed the original VascuQoL when evaluated for treatment, and 127 also completed the questionnaire 6 months after a vascular procedure. The VascuQoL-25 was reduced based on cognitive interviews and psychometric testing. The short instrument, the VascuQoL-6, was tested using item-response theory, exploring structure, precision, item fit, and targeting. A subgroup of 21 individuals with intermittent claudication was also tested correlating the results of VascuQoL-6 to the actual walking capacity, as measured using global positioning system technology. RESULTS: On the basis of structured psychometric testing, the six most informative items were selected (VascuQoL-6) and tested vs the original VascuQoL-25. The correlation between VascuQoL-25 and VascuQoL-6 was r = 0.88 before intervention, r = 0.96 after intervention, and the difference was r = 0.91 (P < .001). The Cronbach α for the VascuQoL-6 was .85 before and .94 after intervention. Cognitive interviews indicated that the responders considered all six items to be relevant and comprehensible. Rasch analysis was used to reduce response options from seven (VascuQoL-25) to four (VascuQoL-6). VascuQol-6 was shown to have high precision and discriminative properties. Item fit was excellent, with both "infit" and "outfit" between 0.7 and 1.3 for all six items. The standardized response mean after intervention was 1.15, indicating good responsiveness to clinical change. VascuQoL-6 results correlated strongly (r = 0.72; P < .001) with the actual measured walking ability (n = 21). CONCLUSIONS: VascuQoL-6 is a valid and responsive instrument for the assessment of health-related quality of life in PAD. The main advantage is the compact format that offers a possibility for routine use in busy clinical settings.

Assessment of functional status and quality of life in claudication.

BACKGROUND: Treadmill walking is commonly used to evaluate walking impairment and efficacy of treatment for intermittent claudication (IC) in clinical and research settings. Although this is an important measure, it does not provide information about how patients perceive the effects of their treatments on more global measures of health-related quality of life (HRQOL). METHODS: PubMed/Medline was searched to find publications about the most commonly used questionnaires to assess functional status and/or general and disease-specific HRQOL in patients with peripheral artery disease (PAD) who experience IC. Inclusion criteria for questionnaires were based on existence of a body of literature in symptomatic PAD. RESULTS: Six general questionnaires and seven disease-specific questionnaires are included, with details about the number of domains covered and how each tool is scored. The Medical Outcomes Study Short Form 36-item questionnaire and Walking Impairment Questionnaire are currently the most used general and disease-specific questionnaires at baseline and after treatment for IC, respectively. CONCLUSIONS: The use of tools that assess functional status and HRQOL has importance in both the clinical and research areas to assess treatment efficacy from the patient's perspective. Therefore, assessing HRQOL in addition to treadmill-measured walking ability provides insight as to the effects of treatments on patient outcomes and may help guide therapy.

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

OBJECTIVES: To examine the accuracy of previously developed prediction models of treadmill walking performance in patients with intermittent claudication (IC) due to peripheral arterial disease (PAD); and to examine the accuracy of new prediction models. DESIGN: Analysis of data collected in a previous randomised clinical trial. MATERIALS: Ninety-three assessments of 28 patients diagnosed with IC due to PAD. METHODS: Patients undertook routine clinical assessments, quality of life (QOL) questionnaires and treadmill walking tests. Walking performance and estimates based on prediction models were compared via paired t-tests or Wilcoxon Rank Sum tests. Stepwise linear regression generated models to predict walking performance from clinical measures and QOL responses. Accuracy was determined as the absolute error between model estimates and patient results. RESULTS: Walking performance was significantly underestimated (35-71% error) by previously developed prediction models. Models developed in the current study identified QOL responses as the most significant predictors of current walking performance but these models still resulted in substantial errors (19-84%). CONCLUSIONS: Previously published predictors of walking performance significantly underestimated patient's ability in practise. Predictions based upon clinical measurements and QOL responses were developed however, their accuracy was also limited. Further research is needed regarding walking performance prediction to assist clinicians with assessment of PAD severity and treatment effectiveness.

Computerized dynamic posturography in the objective assessment of balance in patients with intermittent claudication.

One-third of all elderly patients fall each year and impaired balance has been recognized as a specific risk factor. Intermittent claudication is common among the elderly population, affecting approximately 5% of the population over the age of 50. The aim of this proof-of-concept study was to assess the prevalence of impaired balance among elderly claudicants and to assess each patient's insight into their own risk of falling. A total of 58 claudicants (45 men), median age of 70 (interquartile range = 65-73) years, underwent objective balance assessment by using computerized dynamic posturography. As compared with 195 (5%) historic controls, 24 (41%) of the claudicants demonstrated abnormal balance when the Sensory Organization Test (SOT) was used. Vestibular dysfunction occurred in 52% of the claudicants. Abnormalities including somatosensory (22%), visual function (17%), and preferential reliance on inaccurate visual cues (17%) occurred less often. Prolonged Motor Control Test latency times were uncommon (n = 13) and were in most cases evenly distributed between those with normal (n = 7) and abnormal (n = 6) composite SOT scores. There was a significant difference in history of falling between claudicants with abnormal and normal SOT scores (p = 0.003), with a higher number of patients with abnormal SOT having experienced falling in the past year. However, no correlation between fear of falling and composite SOT score was found (Spearman rank correlation, r = 0.124; p = 0.381). Impaired balance, particularly secondary to vestibular problems, is very common among claudicants and may predispose to a high incidence of falls. Claudicants with abnormal balance are more likely to have a history of falls but not a fear of falling, thus potentially rendering these patients to be at a greater risk.

Evaluation of a telephone clinic for patients with intermittent claudication.

Although the majority of patients with intermittent claudication are stable, those who develop complications can quickly deteriorate and need a rapid response. Because the majority of issues dealt with at a routine follow-up visit are in the form of a discussion, rely on symptoms and do not require an examination, it was considered appropriate to assess if a telephone follow-up service could replace these face-to-face meetings at the authors hospital. This article discusses an evaluation, the objective of which was to pilot a nurse-led telephone follow-up system for claudicant patients in terms of feasibility, patient satisfaction and impact on out-patient vascular surgery practice. This system would maintain supervision of vascular patients to enable fast-tracking into the out-patient clinic/hospital if their symptoms deteriorated. The effectiveness of the nurse-led follow up was assessed by a retrospective analysis of the out-patient clinic attendances before and after introduction of the nurse follow-up service. Attendances decreased, leading the authors to conclude that a structured follow-up system using a telephone clinic run by a skilled and specialized vascular nurse provides excellent support and effective surveillance in patients with intermittent claudication.

Risk attitudes to treatment among patients with severe intermittent claudication.

OBJECTIVES: To determine claudication patients' risk attitude to invasive treatment and whether this treatment is cost effective. METHODS: Quality of life and health state utility status of 50 consecutive patients with severe intermittent claudication was assessed and compared with ankle-brachial pressure index values (ABPI) and results from treadmill tests before and after endovascular or open revascularization. Health utility scores were then calculated and used in a cost-utility analysis. RESULTS: Before surgery, patients were assigned a utility score of 0.51 (EQ-5D index) for their disease, and the standard gamble (SG) and time trade-off (TTO) median scores were 0.88 and 0.70, respectively. Before treatment, a weak correlation (r = 0.43, P < .001) between having a high risk perception of treatment and patients' walking distance were observed, where patients able to walk short distances accepted a higher risk. After treatment, ABI (P = .003) and walking distance (P = .002) improved significantly as well the physical components of the quality of life instruments (P < .001). The surgical treatment generated an improvement in quality of life expressed in QALYs equivalent to 0.17. With an estimated survival of 5 years, it adds up to a value of 0.85, corresponding to a sum of 51,000 US dollars gained. CONCLUSIONS: Patients with severe intermittent claudication are risk-seeking when it comes to surgical treatment and their risk attitude is correlated to their walking ability and quality of life. The incremental QALYs gained by treatment are achieved at a reasonable cost and revascularization appears to be cost effective.

The Australian Vascular Quality of Life Index (AUSVIQUOL): an improved clinical quality of life tool for peripheral vascular disease.

OBJECTIVES: To validate the Australian Vascular Quality of Life Index (AUSVIQUOL) as a quality of life (QOL) tool appropriate for peripheral vascular disease patients in the clinical setting. DESIGN: Cross-sectional study. MATERIALS: The study group consisted of 71 patients with vascular claudication of varying severity attending a tertiary hospital outpatient department. METHODS: The results of the AUSVIQUOL and Medical Outcomes Short Form Health Survey (SF-36) were compared through factor and regression analyses. A group of 12 patients was then reassessed to compare the reliability and internal consistency of the two indices. RESULTS: The AUSVIQUOL took less time to complete than the SF-36 (3.27 v 10.79 min; p<0.0001) and fewer patients found the questions confusing (2% v 26%). The AUSVIQUOL was easier to administer and had a higher level of patient acceptance than the SF-36. The regression analysis showed that for each of the domains in the AUSVIQUOL there was a significant correlation with measures in the SF-36 (adjusted R-squared 0.420, 0.480 and 0.331). The AUSVIQUOL demonstrated a good level of internal consistency when compared to the SF-36 (Cronbach's alpha 0.8702 vs 0.6307). CONCLUSION: In comparison with the SF-36, the AUSVIQUOL is an improved tool for the QOL assessment of patients with peripheral vascular disease in the clinical setting.