Comparison of Graded versus Constant Treadmill Test Protocols for Quantifying Intermittent Claudication

Abstract

The standard method for quantifying the symptoms of intermittent claudication is by using treadmill walking distance. It has recently been suggested that a graded exercise test is much more reproducible than a constant load exercise test. Graded protocols have also been claimed to abolish the placebo effect that has been reported with the constant load test. The reproducibility of absolute claudication distance (ACD) and initial claudication distance (ICD) using a constant load was compared to the graded load treadmill protocol. Fourteen patients (mean age 66 years) with varying severity of stable intermittent claudication were tested using a constant load (3.2 km/h, 10% gradient) and a graded load (3.2 km/h, 0% gradient increasing by 3.5% every 3 min). Patients were tested twice using each protocol in a random sequence, with a minimum 2 day interval between visits. Intra-class correlation coefficient (R) with a constant load protocol for ICD and ACD was R = 0.68, R = 0.93, respectively. With a graded protocol R = 0.84 for ICD and R = 0.98 for ACD. Relative coefficient of repeatability for ICD and ACD during constant load tests were 1.47 and 1.90 respectively and with a graded load test were 1.69 and 1.52 respectively. It was concluded that the graded load test was more reproducible than the constant load test but only by a small margin, whilst ACD was much more reproducible than ICD using either protocol.

Variability and short-term determinants of walking capacity in patients with intermittent claudication

“…The 43% CV found for the short-term variability of WDBS during each stroll is larger than the 15% to 30% test-retest CV generally reported for MWD in PAD patients. [1][2][3][4][5][6] We believe this is also the first study to report PSD as the dominant parameter associated to WDBS.…”

“…What is available is only the reproducibility of maximal walking distance (MWD) through test-rest experiments. [1][2][3][4][5][6] The study of this short-term variability (changes in WDBS within a single stroll) could provide interesting information about some of the issues relating to functional assessment in PAD patients. Indeed, if such short-term variability exists, it may contribute to the difficulties experienced by patients with arterial claudication to estimate their MWD at usual pace, where MWD would be the highest WDBS within a stroll.…”

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

“…[42][43][44][45] The other four studies compared more treadmill protocols within the same group of patients. [46][47][48][49] Both C-and G-protocols were tested. The majority used a velocity of 3.2 km/hour, but also 2, 3, and 4 km/hour were used.…”

Studies on the Effectiveness and Safety of Cilostazol, Beraprost Sodium, Prostaglandin E₁ for the Treatment of Intermittent Claudication

“…Comparisons of increases of WMD from the baseline versus the placebo for both parameters (MWD and PFWD) among the 3 drugs found that changes for beraprost and PGE 1 were larger than those seen for cilostazol. Although MWD is known to be superior in reproducibility compared to PFWD, 22) we consider PFWD to be the more important parameter than MWD because PFWD increases are directly connected to the patients' QOL. For averages in the increased PFWD throughout the study periods, there were large diŠerences in the increased PFWD among the 3 drugs (cilostazol 39.8 m in 20 weeks, beraprost 69.0 m in 12 weeks, PGE 1 55.7 m in 5.3 weeks).…”