Reproducibility of Toe Pressure Measurements

Abstract

Introduction Ankle/brachial indices are inaccurate in the presence of calcification, and physicians may rely on the measurement of digital pressures. As the population continues to age and with the escalation in type 2 diabetes, the importance of, and reliance on, toe pressure measurements will increase. The aim of this study was to assess the reproducibility of toe pressure measurements in a single vascular laboratory. Methods Repeated ankle/brachial indices and toe pressures were measured in 20 patients (10 with known peripheral vascular disease and 10 with aneurysmal or carotid artery disease but no history of PVD), and 10 control patients. Three measurements were made 48 hours apart. All measurements were made by a single vascular technologist. Reproducibility was assessed by the use of the repeatability coefficient and the intraclass correlation coefficient. Results Ankle/brachial indices ranged from 0.36 to 2.4, toe pressures from 18 mmHg to 173 mmHg, and toe/brachial indices from 0.11 to 1.1. The repeatability coefficient showed no significant difference between measurements ( p > 0.1) and the intraclass correlation coefficient estimates showed high agreement between repeated measurements (0.77–0.99). Bland-Altman plots indicated that the observer variability was equally distributed across the range of pressure measurements. Conclusion These results confirm the intraobserver reproducibility of toe pressure measurements; however, further work is required to demonstrate inter-observer reproducibility.

The reliability of toe systolic pressure and the toe brachial index in patients with diabetes

“…The intra-rater ICC values for toe pressures and TBIs ranged from 0.83 to 0.89 and 0.72 to 0.83, respectively. These results are comparable to the findings from the studies by de Graaff et al [29] and Scanlon et al However, our study adds to the work of Cloete et al [30] and deGraaff et al [28] who only assessed intra-rater reliability.…”

“…There is limited research exploring the reliability of toe systolic pressures and TBIs in patients with diabetes, particularly with respect to the newer, more affordable devices. Some research has explored reliability of the measurement of Toe Systolic Pressures in patients with diabetes and varying stages of PAOD with intra-class correlations (ICCs) ranging from 0.77 to 0.99 in intrarater reliability [28][29][30][31] and 0.85 to 0.93 in inter-rater reliability [29,31] (Table 1). De Graaff and colleagues assessed the reliability of toe systolic pressures in 60 patients with 36% with diabetes [21].…”

“…In this particular study, an automatic photoplethsmography (PPG) system was used to obtain the systolic pressures; the reliability was not investigated using a manual PPG unit. Additional points with the past research include difficulty in interpreting the results as the error range in the units of measurement were not reported in most of the studies [28][29][30] The methodology and protocol were briefly explained and only intra-rater reliability was investigated in two of the studies [28,30].…”

Vascular assessment techniques of podiatrists in Australia and New Zealand: a web‐based survey

“…A number of tests are currently used for lower limb vascular assessment including pulse palpation, systolic toe pressures, toe-brachial index (TBI), ankle-brachial index (ABI) and Doppler examination. While generally these tests have been shown to have high reliability and diagnostic accuracy [4][5][6][7][8][9][10][11][12], there has been little investigation of the frequency of use and practicality of performing these assessments in clinical practice generally, with most evidence relating to the most widely recommended test, the ABI [13].…”