Discussion: “Development and Psychometric Validation of a Patient-Reported Outcome Measure for Arm Lymphedema: LYMPH-Q Upper Extremity Module”

Abstract

The present study aims to expand on the authors’ extensive experience with the development of patient-reported outcome measures (PROMs) for evaluation of patients suffering from breast cancer-related lymphedema (BCRL). Although 14 lymphedema-specific PROMs have been developed to measure upper extremity lymphedema outcomes from the patient perspective, a systematic literature review identified that 13 of these were developed with limited input from patients, which is crucial to ensure content validity, and all had low to moderate reliability and validity. The LYMPH-Q Upper Extremity Module introduced here was developed using a psychometric approach with consideration of the patient’s perception of the degree of debilitation and response to treatment, as well as input from 15 patients and 12 medical professionals, followed by validation with 364 patients in the USA and 2858 Danish patients. A validated PROM is unquestionably vital to the care of patients suffering from lymphedema, which plagues a significant portion of patients undergoing treatment for breast cancer. In particular, it is critical to have an objective measure to determine the efficacy of treatment, as many insurance providers continue to deny coverage for lymphedema surgery on the basis of a lack of objective evidence confirming its efficacy. High-volume lymphedema surgeons are able to achieve successful, reproducible outcomes using either lymphovenous bypass (LVB) or vascularized lymph node transfer (VLNT) approaches, and the combined approach has now been demonstrated to achieve superior outcomes. Data confirming improvements in patients’ quality of life following surgery are critical to demonstrate the benefit of lymphedema surgery and justify the need for coverage of these operations. The finding in this study that wearing a compression sleeve within the past year was associated with worse outcomes on all six scales is an important justification for lymphedema surgery, which is the only way that this can be achieved. With the validated LYMPH-Q based on input from patients and medical providers and implementation with 3222 patients, increased utilization of this PROM will provide further confirmation of the efficacy of lymphedema surgery and a common assessment tool with comparable scoring that can help to facilitate international research into these treatments. While the LYMPH-Q is undoubtedly a useful tool that will have tremendous potential, it was based on input from 15 patients, which is somewhat limited and consisted predominantly of Caucasian patients. As the patients were volunteers from a larger cohort of 58 patients, there could be issues of selection bias from the input of the 15 patients whose experience with lymphedema and degree of debilitation is clearly subjective and may be exaggerated compared with others, or perhaps underestimated. Issues such as the degree of dependency on complete decongestive therapy (CDT), number of infections, whether the patient was hospitalized, hand dominance, and employment and occupation can all affect patient responses, which may not be fully addressed with a limited sample size. This similarly affects the validation of the LYMPH-Q using 16 patients with lymphedema. As the authors acknowledge, of the 3222 participants in the field-test sample, the majority were Danish (89%) and White (87%), which limits Society of Surgical Oncology 2021