Saskia P.A. Nicolaï

The walking impairment questionnaire: An effective tool to assess the effect of treatment in patients with intermittent claudication

OBJECTIVE Assessment of walking distance by treadmill testing is the most commonly used method to evaluate the effect of treatment in patients with peripheral arterial disease. However, treadmill testing is time consuming, relatively expensive, and does not adequately reflect real life functional ability. We hypothesized that the Walking Impairment Questionnaire (WIQ) could be an alternative tool to assess objective improvement in functional walking ability of patients with intermittent claudication. METHODS This was a validation study. It was conducted through the outpatient clinic for vascular surgery. Patients with intermittent claudication were referred for supervised exercise therapy. Treadmill testing (absolute claudication distance [ACD]), WIQ, and quality of life questionnaires (RAND-36 and EuroQol) were administered at study onset and after 3 months of supervised exercise therapy. Responsiveness was determined by mean changes in and correlation coefficients of WIQ, ACD, and quality of life questionnaires. Patients were categorized into quartiles based on the increase in ACD, which were subsequently related to change in WIQ and quality of life. RESULTS The mean pre- and post-treatment total WIQ scores of 91 patients were 0.45 (0.22) and 0.58 (0.22), respectively. The correlation coefficient between the change in total WIQ score and ACD was 0.331 (P = .004). A 0.1 change in total WIQ score corresponded to a change of 345 meters in ACD. Analysis of the four quartiles compared to an increase in ACD showed that a greater increase in ACD corresponded with a greater increase in WIQ score, from 0.06 to 0.25 (P = .011). CONCLUSION These data indicate that the WIQ is a valid tool to detect improvement or deterioration in the daily walking ability of patients with intermittent claudication. Hence, the WIQ can be used as an alternative to treadmill testing for objective assessment of functional walking ability, both in daily practice and in clinical trials.

Reliability of treadmill testing in peripheral arterial disease: a meta-regression analysis.

OBJECTIVE A meta-regression analysis was conducted to identify the most reliable treadmill protocol for the assessment of patients with peripheral arterial disease (PAD). BACKGROUND Treadmill testing is the main assessment method to evaluate walking ability in patients with PAD in clinical studies. Reported treadmill protocols are continuous (C) and graded (G) protocols and outcome measurements are initial claudication distance (ICD) and absolute claudication distance (ACD). Variety in protocols might hamper the ability to compare results of different studies. Ideally, future studies should use a protocol with highest reliability. METHODS We searched PubMed and EMBASE (until February 2008) and we hand searched the reference lists. Trials assessing reliability of treadmill testing were identified. Inclusion criteria were the use of a C- or G-protocol, repetition of this protocol, and a retrievable intraclass correlation coefficient (ICC). We identified eight studies in which 658 patients were included. RESULTS For ICD, the estimated reliabilities of the C- and G-protocol (as assessed by the ICC) were 0.85 (95% confidence interval [CI]: 0.82-0.88) and 0.83 (95% CI: 0.80-0.85), respectively, without dependency of the reliability on velocity or grade. For ACD, the reliability was significantly better for the G-protocol (0.95, 95% CI: 0.94-0.96) than for the C-protocol. Moreover, the reliability of the C-protocol was dependent on grade of the treadmill (0%, 10%, and 12%) with a mean ICC of 0.76 (95% CI: 0.54-0.88), 0.89 (95% CI: 0.86-0.91), and 0.91 (95% CI 0.88-0.92), respectively. CONCLUSION Treadmill assessment has the highest reliability when using a G-protocol together with the ACD as the primary outcome measure.

Validation of the Dutch version of the Walking Impairment Questionnaire.

OBJECTIVES The Walking Impairment Questionnaire (WIQ) is a frequently used questionnaire to evaluate patients with intermittent claudication (IC). The aim of this study is to validate the Dutch WIQ for the European situation using the metric system. DESIGN Validation study. MATERIALS After translation and cultural adaptation of the WIQ, 130 patients with IC completed the Dutch WIQ, the RAND-36, and the EuroQol questionnaire. Walking distances were determined by treadmill testing. METHODS Correlations between the WIQ, the two quality of life questionnaires, and walking distances were calculated to determine validity. Reliability and internal consistency were determined using the intraclass correlation coefficient (ICC) and Cronbachs alpha, respectively. RESULTS Significant correlations were found between the WIQ and the absolute claudication distance (ACD) (0.52), EuroQol (0.33) and seven domains of the RAND-36. Test-retest reliability expressed by the ICC was 0.89. The internal consistency determined by Cronbachs alpha was 0.92 for the total WIQ score. Furthermore, a lower WIQ score corresponds to a shorter ACD. CONCLUSIONS This study shows that the Dutch version of the WIQ using the European metric system is a valid, reliable and clinically relevant instrument for assessing walking impairment in patients with intermittent claudication.

Additional supervised exercise therapy after a percutaneous vascular intervention for peripheral arterial disease: a randomized clinical trial.

PURPOSE To determine whether a percutaneous vascular intervention (PVI) combined with supplemental supervised exercise therapy (SET) is more effective than a PVI alone in improving walking ability in patients with symptomatic peripheral arterial disease (PAD). MATERIALS AND METHODS In this prospective randomized trial, patients with PAD treated with a PVI were eligible. Exclusion criteria were major amputation or tissue loss, comorbidity preventing physical activity, insufficient knowledge of the Dutch language, no insurance for SET, and prior participation in a SET program. All patients received a PVI and subsequently were randomly assigned to either the PVI alone group (n = 35) or the PVI + SET group (n = 35). The primary outcome parameter was the absolute claudication distance (ACD). This trial was registered at Clinical trials.gov, NCT00497445. RESULTS The study included 70 patients, most of whom were treated for an aortoiliac lesion. The mean difference in ACD at 6 months of follow-up was 271.3 m (95% confidence interval [CI] 64.0-478.6, P = .011) in favor of additional SET. In the PVI alone group, 1 (3.7%) patient finished the complete treadmill test compared with 11 (32.4%) patients in the PVI + SET group (P = .005). Physical health-related quality-of-life score was 44.1 ± 7.8 in the PVI alone group compared with 41.9 ± 9.5 in the PVI + SET group, which was a nonsignificant difference (P = .34). CONCLUSIONS SET following a PVI is more effective in increasing walking distance compared with a PVI alone. These data indicate that SET is a useful adjunct to a PVI for the treatment of PAD.

Supervised exercise therapy for intermittent claudication in daily practice.

OBJECTIVE This study describes the results and functioning of community-based supervised exercise therapy (SET) at one year of follow-up. METHODS We conducted a prospective cohort study of community-based SET in regional physiotherapeutic practices. Consecutive patients with intermittent claudication referred for community-based SET were included. Exclusion criteria for SET were pain at rest or tissue loss. All patients received a diagnostic workup consisting of an ankle-brachial index at rest and after exercise. Interventions were exercise therapy according to the guidelines of the Royal Dutch Society for Physiotherapy. The primary outcome measurement was the increase in absolute claudication distance (ACD), assessed using a standardized treadmill protocol by a physiotherapist at baseline and at four, 12, 26, and 52 weeks of SET. RESULTS From January 2005 through September 2006, 349 patients were referred by vascular surgeons for community-based SET. A total of 272 patients with intermittent claudication began the program. Of the 349 initially referred patients, 52 could not perform a standard treadmill test but did start community-based SET at a lower level, and 25 patients never started the program. At one year, 129 of the original 272 patients who began community-based SET (47.4%) were available for analysis of walking distance. In the interim, 143 patients discontinued the program for the following reasons: satisfaction with the acquired walking distance (n = 19); unsatisfying results (n = 26); not motivated (n = 22); (non)vascular intercurrent disease (n = 48); and other reasons (n = 28). ACD increased significantly from a median of 400 m at baseline to 1100 m after 12 months of follow-up (P < .001), corresponding to a median increase of 107.8%. CONCLUSION Community-based SET seems as effective as SET in a hospital-based approach in improving walking distance, however, it has a high dropout rate.

Ankle brachial index measurement in primary care: are we doing it right?

BACKGROUND The reference standard for diagnosing peripheral arterial disease in primary care is the ankle brachial index (ABI). Various methods to measure ankle and brachial blood pressures and to calculate the index are described. AIM To compare the ABI measurements performed in primary care with those performed in the vascular laboratory. Furthermore, an inventory was made of methods used to determine the ABI in primary care. DESIGN OF STUDY Cross-sectional study. SETTING Primary care practice and outpatient clinic. METHOD Consecutive patients suspected of peripheral arterial disease based on ABI assessment in primary care practices were included. The ABI measurements were repeated in the vascular laboratory. Referring GPs were interviewed about method of measurement and calculation of the index. From each patient the leg with the lower ABI was used for analysis. RESULTS Ninety-nine patients of 45 primary care practices with a mean ABI of 0.80 (standard deviation [SD] = 0.27) were included. The mean ABI as measured in the vascular laboratory was 0.82 (SD = 0.26). A Bland-Altman plot demonstrated great variability between ABI measurements in primary care practice and the vascular laboratory. Both method of blood pressure measurements and method of calculating the ABI differed greatly between primary care practices. CONCLUSION This study demonstrates that the ABI is often not correctly determined in primary care practice. This phenomenon seems to be due to inaccurate methods for both blood pressure measurements and calculation of the index. A guideline for determining the ABI with a hand-held Doppler, and a training programme seem necessary.

To Wear or not to Wear Compression Stockings after Varicose Vein Stripping: A Randomised Controlled Trial

OBJECTIVES To assess the need to wear compression stockings for 4 weeks after inversion stripping of the great saphenous vein (GSV) from the groin to the level of the knee. DESIGN Randomised controlled trial. PATIENTS A total of 104 consecutive patients with primary complete incompetence of the GSV treated by inversion stripping of the GSV. METHODS Postoperatively treated limbs underwent elastic bandaging for 3 days. Volunteers were randomised to wear a compression stocking for additional 4 weeks (intervention group) or no compression stocking (control group). The primary outcome was limb oedema as assessed by photoelectric leg volume measurement. Secondary outcome measures were pain scores, postoperative complications and return to full work. RESULTS The control leg volume was 3657ml (standard deviation, SD 687) preoperatively and 3640ml (SD 540) 4 weeks postoperatively (non significant, N.S.). The stocking leg volume was 3629ml (SD 540) preoperatively, falling to 3534ml (SD 543) (P<0.01) 4 weeks postoperatively. The difference in leg volume between both the groups was not statistically significant. Patients in the control group resumed work earlier (control 11 days, stocking 15 days, P=0.02, Mann-Whitney test). No difference was observed in the number and type of complication and in pain scores during the 4-week follow-up period. CONCLUSIONS Wearing an elastic compression stocking has no additional benefit following elastic bandaging for 3 days in postoperative care after stripping of the great saphenous vein as assessed by control of limb oedema, pain, complications and return to work.

Functional claudication distance: a reliable and valid measurement to assess functional limitation in patients with intermittent claudication

BackgroundDisease severity and functional impairment in patients with intermittent claudication is usually quantified by the measurement of pain-free walking distance (intermittent claudication distance, ICD) and maximal walking distance (absolute claudication distance, ACD). However, the distance at which a patient would prefer to stop because of claudication pain seems a definition that is more correspondent with the actual daily life walking distance. We conducted a study in which the distance a patient prefers to stop was defined as the functional claudication distance (FCD), and estimated the reliability and validity of this measurement.MethodsIn this clinical validity study we included patients with intermittent claudication, following a supervised exercise therapy program. The first study part consisted of two standardised treadmill tests. During each test ICD, FCD and ACD were determined. Primary endpoint was the reliability as represented by the calculated intra-class correlation coefficients. In the second study part patients performed a standardised treadmill test and filled out the Rand-36 questionnaire. Spearmans rho was calculated to assess validity.ResultsThe intra-class correlation coefficients of ICD, FCD and ACD were 0.940, 0.959, and 0.975 respectively. FCD correlated significantly with five out of nine domains, namely physical function (rho = 0.571), physical role (rho = 0.532), vitality (rho = 0.416), pain (rho = 0.416) and health change (rho = 0.414).ConclusionFCD is a reliable and valid measurement for determining functional capacity in trained patients with intermittent claudication. Furthermore it seems that FCD better reflects the actual functional impairment. In future studies, FCD could be used alongside ICD and ACD.

Pocket Doppler and vascular laboratory equipment yield comparable results for ankle brachial index measurement

BackgroundThe ankle brachial index (ABI) is a well-established tool for screening and diagnosis of peripheral arterial disease (PAD). In this study we assessed the validity of ABI determination using a pocket Doppler device compared with automatic vascular laboratory measurement in patients suspected of PAD.MethodsConsecutive patients with symptoms of PAD referred for ABI measurement between December 2006 and August 2007 were included. Resting ABI was determined with a pocket Doppler, followed by ABI measurement with automatic vascular laboratory equipment, performed by an experienced vascular technician. The leg with the lowest ABI was used for analysis.ResultsFrom 99 patients the mean resting ABI was 0.80 measured with the pocket Doppler and 0.85 measured with vascular laboratory equipment. A Bland-Altman plot demonstrated great correspondence between the two methods. The mean difference between the two methods was 0.05 (P < .001). Multivariate linear regression analysis showed no dependency of the difference on either the average measured ABI or affected or unaffected leg.ConclusionSince the small, albeit statistically significant, difference between the two methods is not clinically relevant, our study demonstrates that ABI measurements with pocket Doppler and vascular laboratory equipment yield comparable results and can replace each other. Results support the use of the pocket Doppler for screening of PAD, allowing initiation of cardiovascular risk factor management in primary care, provided that the equipment operator is experienced.

Treatment for intermittent claudication and the effects on walking distance and quality of life.

The objective of the study was to provide an overview of the most common treatments for intermittent claudication and to determine the effectiveness in improving walking distance and quality of life based on a combination of direct and indirect evidence. We included trials that compared: angioplasty, surgery, exercise therapy or no treatment for intermittent claudication. Outcome measurements were walking distance (maximum, pain-free) and quality of life (physical, mental). We used a network meta-analysis model for the combination of direct and indirect evidence. We included 42 studies, presenting 3106 participants. The network meta-analysis showed that supervised exercise therapy (Δ = 1.62, P < 0.01), angioplasty (Δ = 1.89, P < 0.01) and surgery (Δ = 2.72, P = 0.02) increased walking distance significantly more than no treatment. Furthermore, supervised exercise therapy (Δ = 0.60, P < 0.01), angioplasty (Δ = 0.91, P = 0.01) and surgery (Δ = 1.07, P < 0.01) increased physical quality of life more than no treatment. However, in the sensitivity analysis, only supervised exercise therapy had additional value over no symptomatic treatment (Δ = 0.66, P < 0.01). In conclusion, this network meta-analysis indicates that supervised exercise therapy is more effective in both increasing walking distance and physical quality of life, compared with no treatment. Angioplasty and surgery also increase walking distance, compared with no treatment, but results for physical quality of life are less convincing.