title: L-dex ratio in detecting breast cancer-related lymphedema: reliability, sensitivity, and specificity.
abstract: Advances in bioelectrical impedance analysis (BIA) permit the assessment of lymphedema by directly measuring lymph fluid changes. The objective of the study was to examine the reliability, sensitivity, and specificity of cross-sectional assessment of BIA in detecting lymphedema in a large metropolitan clinical setting. BIA was used to measure lymph fluid changes. Limb volume by sequential circumferential tape measurement was used to validate the presence of lymphedema. Data were collected from 250 women, including healthy female adults, breast cancer survivors with lymphedema, and those at risk for lymphedema. Reliability, sensitivity, specificity and area under the ROC curve were estimated. BIA ratio, as indicated by L-Dex ratio, was highly reliable among healthy women (ICC=0.99; 95% CI = 0.99 - 0.99), survivors at-risk for lymphedema (ICC=0.99; 95% CI = 0.99 - 0.99), and all women (ICC=0.85; 95% CI = 0.81 - 0.87); reliability was acceptable for survivors with lymphedema (ICC=0.69; 95% CI = 0.54 to 0.80). The L-Dex ratio with a diagnostic cutoff of >+7.1 discriminated between at-risk breast cancer survivors and those with lymphedema with 80% sensitivity and 90% specificity (AUC=0.86). BIA ratio was significantly correlated with limb volume by sequential circumferential tape measurement. Cross-sectional assessment of BIA may have a role in clinical practice by adding confidence in detecting lymphedema. It is important to note that using a cutoff of L-Dex ratio >+7.1 still misses 20% of true lymphedema cases, it is important for clinicians to integrate other assessment methods (such as self-report, clinical observation, or perometry) to ensure the accurate detection of lymphedema.
authors.affiliation: College of Nursing, New York University, New York, USA. mf67@nyu.edu
authors.forename: M R
authors.initials: MR
authors.lastname: Fu
authors.affiliation: College of Nursing, New York University, New York, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Cleland
authors.affiliation: Department of Surgery, New York University School of Medicine, New York, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Guth
authors.affiliation: Department of Medicine, Columbia University, New York, NY, USA.
authors.forename: M
authors.initials: M
authors.lastname: Kayal
authors.affiliation: College of Nursing, New York University, New York, USA.
authors.forename: J
authors.initials: J
authors.lastname: Haber
authors.affiliation: Department of Nursing and Oncology Services, NYU Langone Medical Center, New York, USA.
authors.forename: F
authors.initials: F
authors.lastname: Cartwright
authors.affiliation: NYU Clinical Cancer Center, NYU Langone Medical Center, New York, USA.
authors.forename: R
authors.initials: R
authors.lastname: Kleinman
authors.affiliation: Department of Statistics, Columbia University, New York, NY, USA
authors.forename: Y
authors.initials: Y
authors.lastname: Kang
authors.affiliation: NYU Clinical Cancer Center, NYU Langone Medical Center, New York, USA.
authors.forename: J
authors.initials: J
authors.lastname: Scagliola
authors.affiliation: Department of Surgery, New York University School of Medicine, New York, USA.
authors.forename: D
authors.initials: D
authors.lastname: Axelrod
mesh_terms: D001132:Arm / Q000473:pathology*; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000628:therapy*; D018592:Cross-Over Studies; D017097:Electric Impedance; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008209:Lymphedema / Q000175:diagnosis* / Q000209:etiology*; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity