highly significantp < 0.001
In RS and iCPO patients with FD, a highly significant association was found in CP grade between the two groups ( p < 0.001); while a grade 3 and 4 CP was most common in RS patients with FD (grade 3 = 60 %, n = 37; grade 4 = 23 %, n = 14), a grade 2 CP was most common in iCPO patients with FD (50 %; n = 19; Table 4 ).