In patients with systemic vasculitis, collection of data using the computed adaptive testing (CAT) Patient-Reported Outcome Measurement Information System (PROMIS) instrument was feasible and exhibited some cross-sectional and longitudinal construct validity, according to data from a multicenter, longitudinal cohort study published in The Journal of Rheumatology.
Researchers selected 10 PROMIS item banks instruments for the analysis. All study participants completed PROMIS instruments using CAT. The Short Form 36 (SF-36) was also administered. The assessment of cross-sectional construct validity was performed by calculating the correlations of PROMIS scores with SF-36 measures, as well as with physician and patient global scores to determine disease severity. Longitudinal construct validity was evaluated by correlations of between-visit differences in PROMIS scores with differences in other measurements.
Over the duration of the study period, 1040 patients with systemic vasculitis attended quarterly or yearly in-person visits for the Vasculitis Clinical Research Consortium Longitudinal Study, an ongoing, observational, longitudinal cohort funded by the National Institutes of Health. Of the 1040 patients, 973 began a PROMIS assessment and were entered into the study. During the study, the 973 participants attended a total of 2306 study visits, and PROMIS was completed at 99% (2276 of 2306) of the visits. The median time required by participants to complete each PROMIS instrument ranged between 40 and 55 seconds.
The PROMIS instruments correlated cross-sectionally with individual scales of the SF-36, most strongly with subscales of the SF-36 that address the same domain as the PROMIS instrument. For instance, the fatigue PROMIS score correlated with both the mental component score (MCS; r= –0.54) and the physical component score (PCS; r= –0.65). Moreover, although the physical function PROMIS score correlated strongly with PCS (r= 0.81), it correlated weakly with MCS (r= 0.29). Weaker relationships were reported longitudinally between changes in PROMIS scores and changes in PCS and MCS.
The investigators noted that these findings will help expand the options available for capturing patient-reported outcomes in the evaluation of vasculitis to assess the burden of disease.
Tomasson G, Farrar JT, Cuthbertson D, et al; Vasculitis Clinical Research Consortium. Feasibility and construct validation of the Patient Reported Outcomes Measurement Information System (PROMIS) in systemic vasculitis [published online March 1, 2019]. J Rheumatol. doi:10.3899/jrheum.171405