After using the noninferiority test , the mean difference ( @ % confidence interval ) of WOMAC total , WOMAC pain , and WOMAC function scores at week @ adjusted by values at week @ of C. domestica extracts were noninferior to those for the ibuprofen group ( P = @ , P = @ , and P = @ , respectively ) , except for the WOMAC stiffness subscale , which showed a trend toward significance ( P = @ ) .