Scale Linking to Enable Patient-Reported Outcome Performance Measures Assessed with Different Patient-Reported Outcome Measures

Background: Patient-reported outcome performance measures (PRO-PMs) incorporate outcomes from the patient's perspective into performance measures and may have great potential to impact health care. The various patient-reported outcome measures (PROMS) used to assess the same outcome challenge widespread use of PRO-PMs. A potential solution is to statistically link PROMS to provide equivalent PRO-PM conclusions to be drawn regardless of which PROM was used. Objectives: To determine the level of agreement in the performance of two depression-related PRO-PMs assessed using the nine-item Patient Health Questionnaire (PHQ-9) depression scale and the eight-item Patient-Reported Outcomes Measurement Information System (PROMIS) Depression short form and the PHQ-9 cocalibrated on the PROMIS metric. Methods: We conducted a retrospective cohort study of patients who visited one of eight ambulatory neurological and psychiatric clinics at the Cleveland Clinic between January 23 and June 15, 2012, and who completed both the PHQ-9 and PROMIS Depression scales at the same visit. The level of agreement was measured between PRO-PM performance assessed with standard scoring of the PHQ-9, the PROMIS cocalibrated scoring of the PHQ-9, and the PROMIS score for two depression-related PRO-PMs. Results: Of the 5736 enrolled patients, 701 had PROMS from two or more visits. Differences in performance of the depression remission PRO-PM ranged from 0.4% to 2.1%, and differences in the progress toward remission PRO-PM ranged from 0.9% to 5.1%, depending on which depression score was used. Conclusions: There was a high level of agreement in the PRO-PM for depression when incorporating different PROMS. These findings support the ability to use linkage of scale scores to assess performance of PRO-PMs with different PROMS.