Responsiveness and interpretation of the PROMIS Cancer Function Brief 3D Profile

Background: Measuring function with valid and responsive tools in patients with cancer is essential for driving clinical decision-making and for the end points of clinical trials. Current patient-reported outcome measurements of function fall short for many reasons. This study evaluates the responsiveness of the Patient-Reported Outcomes Measurement Information System (PROMIS) Cancer Function Brief 3D Profile, a novel measure of function across multiple domains. Methods: Two hundred nine participants across five geographically distinct tertiary care centers completed the assessment and pain rating at two outpatient cancer rehabilitation clinic visits. Patients and providers completed a global rating of change measure at the second visit to indicate whether the patient was improving or worsening in function. Multiple response indices and linear models measured whether the measure was responsive to self-reported and clinician-rated changes over time. Correlations between changes in function and changes in anchors (pain rating and performance status) were also calculated. Results: Function as measured by the PROMIS Cancer Function Brief 3D Profile changed appropriately as both patients and clinicians rated change. Small to moderate effect sizes supported the tool's responsiveness. Function was moderately correlated with pain and more strongly correlated with performance status, and changes in function corresponded with changes in anchor variables. No floor/ceiling effect was found. Conclusions: The PROMIS Cancer Function Brief 3D Profile is sensitive to changes over time in patients with cancer. The measure may be useful in clinical practice and as an end point in clinical trials. Lay summary: We gave patients a questionnaire by which they told their physicians how well they were functioning, including how fatigued they were. This study tested that questionnaire to see whether the scores would change if patients got better or worse.