The reliability and concurrent validity of the figure-of-eight method of measuring hand edema in patients with burns

OBJECTIVE: Water volumetry is considered the "gold standard" for hand edema assessment. This technique requires considerable time, staff, and specialized equipment. The figure-of-eight method for hand edema assessment has been tested only in the orthopedic population. The objective of this study was to test the reliability and concurrent validity of the figure-of-eight method of measuring hand edema in the burn patient population. METHODS: We conducted a prospective blinded study with 20 burned patients (33 edematous hands) admitted from February to May 2005. Two testers performed three separate blinded measurements on each edematous hand, using the figure-of-eight technique. A third tester performed two measurements, using water volumetry. An independent investigator recorded all measurements. Intratester and intertester reliability were analyzed. Concurrent validity was examined and compared with water volumetry measurements. RESULTS: Intraclass correlation coefficients (ICC) for the intratester reliability of the figure-of-eight method were 0.96 for tester 1 and 0.97 for tester 2. The ICC for intertester reliability of the figure-of-eight measurements was 0.94. The intratester ICC for volumetric measurements was 0.99. Correlation coefficient (Pearson's) for tester 1 was 0.83 (P < .01), and for tester 2, 0.89 (P < .01). CONCLUSION: The figure-of-eight technique is a reliable and valid measurement tool for measuring hand edema. This technique is a more clinically feasible tool than water volumetry in the burn patient population.