Establishing clinical severity for PROMIS ® measures in adult patients with rheumatic diseases.

PURPOSE: Different patient-reported outcome (PRO) measures are used for rheumatic diseases (RD). The aims of this study are-(1) Identify PROMIS® domains most relevant to care of patients with RD, (2) Collect T-Score metrics in patients with RD, and (3) Identify clinically meaningful cut-points for these domains.

METHODS: A convenience sample of RD patients was recruited consecutively during clinic visits, and asked to complete computer-adaptive tests on thirteen Patient-Reported Outcomes Measurement Information System (PROMIS® ) instruments. Based on discussion with clinical providers, four measures were chosen to be relevant and actionable (from rheumatologists' perspective) in RD patients. Data from RD patients were used to develop clinical vignettes across a range of symptom severity. Vignettes were created based on most likely item responses at different levels on the T-score metric (mean = 50; SD = 10) and anchored at 5-point intervals (0.5 SDs). Patients with RD (N = 9) and clinical providers (N = 10) participated as expert panelists in separate one-day meetings using a modified educational standard setting method.

RESULTS: Four domains (physical function, pain interferences, sleep disturbance, depression) that are actionable at the point-of-care were selected. For all domains, patients endorsed cut-points at lower levels of impairment than providers by 0.5 to 1 SD (e.g., severe impairment in physical function was defined as a T-score of 35 by patients and 25 by providers).

CONCLUSIONS: We used a modified educational method to estimate clinically relevant cut-points to classify severity for PROMIS measures This allows for meaningful interpretation of PROMIS® measures in a clinical setting of RD population.