Description
Calculate TwoDcDAPSA: PROs-Joint Contrast (PJC) Score and Quartiles.
Description
Provides a calculator for the two-dimensional clinical Disease Activity index for Psoriatic Arthritis (TwoDcDAPSA), a principal component-derived measure that complements the conventional clinical DAPSA score. The TwoDcDAPSA captures residual variation in patient-reported outcomes (pain and patient global assessment) and joint counts (swollen and tender) after adjusting for standardized cDAPSA using natural spline coefficients derived from published models. Residuals are standardized and combined with fixed principal component loadings to yield a continuous PROs-Joint Contrast (PJC) score and quartile groupings. The package applies pre-specified coefficients and loadings to new datasets but does not estimate spline models or principal components itself.