Facets of physical function assessed by patient-reported outcome measures in oncology research

The U.S. Food & Drug Administration has identified physical functioning (PF) as a core patient-reported outcome (PRO) in cancer clinical trials. The purpose of this study was to identify PF PRO measures (PROMs) in adult cancer populations and classify the PROMs by content covered (facets of PF) in each measure.

As part of the Patient Reports of Physical Functioning Study (PROPS) research program, we conducted a targeted literature review to identify PROMs that could be used in clinical trials to evaluate PF from the patient perspective. Next, we convened an advisory panel to conduct a modified, reactive, Delphi study to reach consensus on which PF facets are assessed by PROMs identified in the review. The panel engaged in a "card sort" activity to classify PROM items by PF facets. Consensus was reached when 80% of panel members agreed that at least one facet was being measured by each PROM item.

The literature review identified 13 PROMs that met inclusion criteria. Eight facets of PF were identified for classification in the Delphi study: ability, completion, difficulty, limitation, quality, frequency, bother, and satisfaction. Through two rounds, the panel documented and classified conceptual approaches for each PRO item presented. The most prevalent PF facets were ability, difficulty, and limitation.

Classifying PF PROMs by PF facets will promote more consistent communication regarding the aspects of PF represented in each PROM, helping researchers prioritize measures for inclusion in cancer clinical trials.