Background/Purpose:

Patient reported measures of global health and disease activity are increasingly used in routine care; however, detecting meaningful change in clinical status (responsiveness) is difficult to define. Minimal clinically important differences (MCID) are patient derived scores that reflect changes in clinical care that are meaningful for the patient.  Little is known about MCID in many immune mediated diseases. Since small differences in PROs may be statistically significant yet clinically unimportant, it is important to study across disease states.

We evaluated the MCID of PROMIS Global Health (GH) and RAPID3 in multiple immune mediated diseases at point of care.

Methods:

Data from patients with diagnosis codes of rheumatoid arthritis (RA), psoriatic arthritis (PsA), lupus and granulomatosis with polyangiitis (GPA) who had completed PROMIS GH and RAPID3 via MyRheum using computerized adaptive testing (CAT) at two separate visits, six months apart, were included. Paired t-tests were performed to assess the change in PROMIS and RAPID3.   PROMIS MCID change of 5 and RAPID3-weighted score of 1.2   (improvement or worsening) was used to identify important differences.

 Results:

The analyses included more than 7,463 patients (age 58.3±14, female 76.8%, white 86.2%). The complete dataset included 4,845 patients for PROMIS and 6,837 patients for RAPID3.  The differences in PROMIS and RAPID3 scores by diagnosis are displayed in Table 1. The change in PROMIS score was statistically significant overall (p<0.001) as well as for those with a diagnosis of either GPA (p=0.030) or RA (p<0.001), even though the mean change in PROMIS was less than 1 point for all groups.  Approximately 15-20% of patients showed an improvement or worsening of MCID by 6 months. 60-70% had no change between visits. The change in RAPID3 score (table b) from the first to second visit was significant (p<0.001), as was the change for lupus (p=0.048) and RA (p<0.001). Thresholds for clinically meaningful change in PROMIS GH were most significant in GPA and RA compared to PsA and lupus and in RAPID3 were most significant in lupus and RA compared to PsA and GPA.

Conclusion:

This study supports the feasibility of collecting PROMIS GH and RAPID3 scores at point of care in patients with immune mediated diseases and using CAT with significantly reduced patient question burden.  There was improvement on average for PROMIS and RAPID3 scores among all immune mediated diseases after 2 visits. This study highlights that it is unlikely to have a single MCID value applicable across all chronic diseases.  The variability in MCID observed in the MyRheum cohort implies that some patients improve, while others worsen, and this study provides an opportunity to better understand patient characteristics and therapies that my explain these changes in the future.