Reproducibility and day time bias correction of optoelectronic leg volumetry: A prospective cohort study

Abstract

Background: Leg edema is a common manifestation of various underlying pathologies. Reliable measurement tools are required to quantify edema and monitor therapeutic interventions. Aim of the present work was to investigate the reproducibility of optoelectronic leg volumetry over 3 weeks' time period and to eliminate daytime related within-individual variability. Methods. Optoelectronic leg volumetry was performed in 63 hairdressers (mean age 45 16 years, 85.7% female) in standing position twice within a minute for each leg and repeated after 3 weeks. Both lower leg (legBD) and whole limb (limbBF) volumetry were analysed. Reproducibility was expressed as analytical and within-individual coefficients of variance (CVA, CVW), and as intra-class correlation coefficients (ICC). Results: A total of 492 leg volume measurements were analysed. Both legBDand limbBFvolumetry were highly reproducible with CVAof 0.5% and 0.7%, respectively. Within-individual reproducibility of legBDand limbBFvolumetry over a three weeks' period was high (CV W1.3% for both; ICC 0.99 for both). At both visits, the second measurement revealed a significantly higher volume compared to the first measurement with a mean increase of 7.3 ml 14.1 (0.33% 0.58%) for leg BDand 30.1 ml 48.5 ml (0.52% 0.79%) for limbBFvolume. A significant linear correlation between absolute and relative leg volume differences and the difference of exact day time of measurement between the two study visits was found (P