The comparative responsiveness of Hospital Universitario Princesa Index and other composite indices for assessing rheumatoid arthritis activity

Objective To evaluate the responsiveness in terms of correlation of the Hospital Universitario La Princesa Index (HUPI) comparatively to the traditional composite indices used to assess disease activity in rheumatoid arthritis (RA), and to compare the performance of HUPI-based response criteria with that of the EULAR response criteria. Methods Secondary data analysis from the following studies: ACT-RAY (clinical trial), PROAR (early RA cohort) and EMECAR (pre-biologic era long term RA cohort). Responsiveness was evaluated by: 1) comparing change from baseline (Delta) of HUPI with Delta in other scores by calculating correlation coefficients; 2) calculating standardised effect sizes. The accuracy of response by HUPI and by EULAR criteria was analyzed using linear regressions in which the dependent variable was change in global assessment by physician (Delta GDA-Phy). Results Delta HUPI correlation with change in all other indices ranged from 0.387 to 0.791); HUPI's standardized effect size was larger than those from the other indices in each database used. In ACT-RAY, depending on visit, between 65 and 80% of patients were equally classified by HUPI and EULAR response criteria. However, HUPI criteria were slightly more stringent, with higher percentage of patients classified as non-responder, especially at early visits. HUPI response criteria showed a slightly higher accuracy than EULAR response criteria when using Delta GDA-Phy as gold standard. Conclusion HUPI shows good responsiveness in terms of correlation in each studied scenario (clinical trial, early RA cohort, and established RA cohort). Response criteria by HUPI seem more stringent than EULAR's.
Our study was supported by grants RD16/0012/0011 and PI14/00442 from the Ministerio de Economia y Competitividad (Instituto de Salud Carlos III; Spain) and cofunded by the Fondo Europeo de Desarrollo Regional (FEDER). Data from ACT-RAY clinical trial were kindly provided by Hoffmann-La Roche Ltd. No financial support was received from Hoffmann-La Roche Ltd Data from EMECAR and PROAR cohorts were provided by the Spanish Society of Rheumatology. No financial support was received from the Spanish Society of Rheumatology. None of these institutions played any role in the analysis or interpretation of data, nor were they involved in the writing of the manuscript. Roche and Sociedad Espanola de Reumatologia were involved in the collection of data from ACT-RAY, and EMECAR and PROAR, respectively. However, these funders had no role in study design, analysis, decision to publish, or preparation of the manuscript.