PTH and bone disorder: CKD-MBD, chronic kidney disease–mineral and bone disorder; Q, quarter; sP, serum phosphorus; iPTH, intact parathyroid hormone; PB, phosphate binder; nPCR, normalized protein catabolic rate; PD, peritoneal dialysis; Kru, residual kidney function; SO, sucroferric oxyhydroxide; SD, standard deviation