Development of a core set of outcome measures to be applied toward breast cancer-related lymphedema core outcome domains.

Purpose: For breast cancer survivors (BCS) living with breast cancer-related lymphedema (BCRL), what outcome measures (OMs) are recommended to be used to measure standardized outcome domains to fully assess the burden of the disease and efficacy of interventions? An integral component of a standardized core outcome set (COS) are the OMs used to measure the COS.

Methods: A supplemental online survey was linked to a Delphi study investigating a COS for BCRL. OMs were limited to a maximum of 10 options for each outcome domain (OD). There were 14 ODs corresponding to the International Classification of Functioning, Disability, and Health (ICF) framework and respondents rated the OMs with a Likert level of recommendation. The feasibility of the listed OMs was also investigated for most outpatient, inpatient, and research settings.

Results: This study identified 27 standardized OMs with a few ODs having 2-3 highly recommended OMs for proper measurement. A few of the recommended OMs have limitations with reliability due to being semi-quantitative measures requiring the interpretation of the rater.

Conclusion: Narrowing the choices of OMs to 27 highly recommended by BCRL experts may reduce selective reporting, inconsistency in clinical use, and variability of reporting across interdisciplinary healthcare fields which manage or research BCRL. There is a need for valid, reliable, and feasible OMs that measure tissue consistency. Measures of upper extremity activity and motor control need further research in the BCS with BCRL population.