Engaging Ambulatory Cancer Patients to Develop and Validate a Comprehensive New Patient-Reported Outcomes Measure

The ambulatory cancer program in Alberta, Canada routinely collects Patient-Reported Outcomes (PROs) using a common symptom rating measure, the Edmonton Symptom Assessment System-Revised (ESAS-r). The purpose of this study was to redesign, test, and validate a modified ESAS-r (the ESAS-r Cancer) for use in the province's new clinical information system and online patient portal.Patient advisors participated in regular meetings to redesign the measure, creating expanded definitions for the original symptoms and new symptoms, added based on trends identified in our historical PRO data. To test the modified measure, patient advisors first completed the measure online to test the feasibility of remote electronic completion. Next, the advisors participated in cognitive interviews to discuss and finalize the wording of each symptom definition for clarity. To test the validity and reliability of the finalized measure, 1600 randomly sampled patients were mailed paper copies of the ESAS-r Cancer, ESAS-r, and a validated PRO measure called the Memorial System Assessment Scale-Short Form (MSAS-SF), which is often used with cancer patients. Canonical Correlation Analysis and exploratory factor analyses were performed to assess concurrent and construct validity of the ESAS-r Cancer against ESAS-r, using MSAS-SF as the gold standard. Cronbach's α was calculated to assess reliability.The nine original ESAS-r symptoms were retained and six new symptoms were added to create the ESAS-r Cancer. All but one of the 26 patient advisors (96.2%) who completed the online measure did so without assistance. After two rounds of cognitive interviews all symptom definitions were finalized and deemed clear by almost all advisors. 461 patients (29% response rate) completed all three questionnaires. Using MSAS-SF as the gold standard, ESAS-r Cancer showed stronger canonical correlation than ESAS-r, indicating higher concurrent validity and fitting degree. ESAS-r Cancer also accounted for more information included on MSAS-SF than did ESAS-r, explaining more variance (75.2% vs. 73.5%). As revealed by factor analysis, the three-dimensional factor structure of ESAS-r Cancer outperformed the two-dimensional factor structure of ESAS-r, by allowing for new constructs within measurement. The reliability of ESAS-r Cancer was verified (Cronbach's α = .903, > threshold of 0.8) and slightly higher than ESAS-r (Cronbach's α = .884).ESAS-r Cancer is now in use with patients throughout Alberta's cancer program. The redesign, testing, and validation process involved patient engagement throughout. Patient testing and perspectives were critical as ESAS-r Cancer is intended for use with ambulatory cancer patients. ESAS-r Cancer can help ensure patients are included in care decisions and that their perspectives are involved in guiding care.