The agreement between three classification systems used to grade the severity of lymphedema in patients with upper and lower extremity lymphedema: A retrospective study.

Background: Several classification systems are used to grade the severity of lymphedema. Their agreement with each other has not been reported.

Objective: To evaluate the agreement between the American Physical Therapy Association (APTA) criteria, the criteria of Ramos et al., and the International Society of Lymphology (ISL) criteria in patients with upper and lower extremity lymphedema.

Methods: A total of 156 patients (63 and 93 patients with upper and lower extremity lymphedema, respectively) were included. The circumference measurements and limb volume were measured. The severity of lymphedema of the patients was classified as mild, moderate, and severe lymphedema using the APTA criteria, the criteria of Ramos et al., and the ISL criteria. The agreement between the classification systems was assessed with Krippendorff's alpha.

Results: An acceptable and poor agreement were found between the criteria in upper (Krippendorff's alpha > 0.667) and lower extremity lymphedema (Krippendorff's alpha < 0.667), respectively. In pairwise comparisons, an acceptable agreement was found among each comparison in upper extremity lymphedema (Krippendorff's alpha > 0.667), and a poor agreement was found among each comparison in lower extremity lymphedema (Krippendorff's alpha < 0.667) except between the APTA criteria and the criteria of Ramos et al (Krippendorff's alpha > 0.667).

Conclusions: Patients with upper extremity lymphedema classified according to these criteria can be assumed to be samples of the same population; however, patients with lower extremity lymphedema graded according to the ISL criteria may be included in a different classification when they grade with the APTA criteria and the criteria of Ramos et al.