Comparison of body composition assessment methods in breast cancer survivors.

PURPOSE/
OBJECTIVES: To examine and compare the reliability of four body composition methods commonly used in assessing breast cancer survivors.
DESIGN: Cross-sectional.
SETTING: A rehabilitation facility at a university-based comprehensive cancer center in the southeastern United States. SAMPLE: 14 breast cancer survivors aged 40-71 years.
METHODS: Body fat (BF) percentage was estimated via bioelectric impedance analysis (BIA), air displacement plethysmography (ADP), and skinfold thickness (SKF) using both three- and seven-site algorithms, where reliability of the methods was evaluated by conducting two tests for each method (test 1 and test 2), one immediately after the other. An analysis of variance was used to compare the results of BF percentage among the four methods. Intraclass correlation coefficient (ICC) was used to test the reliability of each method. MAIN RESEARCH VARIABLE: BF percentage.
FINDINGS: Significant differences in BF percentage were observed between BIA and all other methods (three-site SKF, p<0.001; seven-site SKF, p<0.001; ADP, p=0.002). No significant differences (p>0.05) in BF percentage between three-site SKF, seven-site SKF, and ADP were observed. ICCs between test 1 and test 2 for each method were BIA=1, ADP=0.98, three-site SKF=0.99, and seven-site SKF=0.94.
CONCLUSIONS: ADP and both SKF methods produce similar estimates of BF percentage in all participants, whereas BIA overestimated BF percentage relative to the other measures. Caution is recommended when using BIA as the body composition method for breast cancer survivors who have completed treatment but are still undergoing adjuvant hormonal therapy. IMPLICATIONS FOR NURSING: Measurements of body composition can be implemented very easily as part of usual care and should serve as an objective outcome measure for interventions designed to promote healthy behaviors among breast cancer survivors.