TwoDcDAPSA - Calculate TwoDcDAPSA: PROs-Joint Contrast (PJC) and
Swollen–Tender Joints Contrast (STC) Scores and Quartiles
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. 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 two continuous component scores: the
PROs-Joint Contrast (PJC) and the Swollen–Tender joints
Contrast (STC), along with quartile-based groupings (including
optional combined quartile groupings). The package applies
pre-specified coefficients, residual standardization, and
loadings to new datasets but does not estimate spline models or
principal components itself.