Reliability and validity of the figure-of-eight method of measuring hand size in patients with breast cancer-related lymphoedema.

Breast cancer-related lymphoedema (BCRL) affects 24-42% of patients following treatment for breast cancer. The gold standard method of measuring hand swelling associated with BCRL is to use water displacement (volumeter). This is not always possible in the clinical setting and the figure-of-eight method, which involves wrapping a simple measuring tape around the hand in a specific way, may be an alternative. The aim of the study was to examine the reliability and validity of the figure-of-eight method of measuring hand size in women with BCRL. Twenty-four patients with hand swelling associated with BCRL participated. Two novice testers performed three 'blinded' figure-of-eight measurements and three volumetric measurements of each hand. In terms of intertester (between-tester) and intratester (within-tester) reliability, the intraclass correlation coefficients were all greater than 0.8 indicating high intra- and intertester reliability for the figure-of-eight method. For validity, a Pearson's moment correlation computed between the figure-of-eight and volumetric methods highlighted a statistically significant correlation of 0.7 between the methods for both testers. The figure-of-eight method was found to be a valid and reliable method of measuring hand swelling in this population.