The 'Phosphorus Week': involvement of Spanish nephrologists in the control of phosphorus blood levels

Background: The adequate control of phosphorus levels is a major concern for professionals involved in the care of patients with chronic kidney disease (CKD), since high phosphorus levels are directly related to an increase in mortality.

Objectives: To know the perception and involvement of Spanish nephrologists on the control of phosphorus levels, the so-called 'Phosphorus Week' was organized (November 13-17, 2017).

Methods: All members of the Spanish Society of Nephrology were invited to participate in an online survey, which included questions on aspects related to phosphorus control in patients with advanced CKD (aCKD) (glomerular filtration rate <30 ml/min/1, 73 m²) and in the different modalities of renal replacement therapies [peritoneal dialysis (PD), hemodialysis (HD) and renal transplantation (KT)].

Results: 72 data entries were obtained in the survey with an inclusion of 7463 patients. Of them, 35.4% were on HD, 34.8% were KT, 24.2% had aCKD and 5.5% were on PD. The serum phosphorus level target for the four groups of patients was 4.5 mg/dl, with minimal variations depending on the area of ​​the national territory. The patients with better control of phosphataemia were patients with KT (93.3% had phosphorus values ​​<4.5 mg/dl), followed by patients with aCKD (65.6% with phosphorus <4.5 mg/dl). Only 53.6% of the patients on HD and 39.4% of those on PD reached the phosphorus goal <4.5 mg/dl. The group of patients on dialysis was the one in whom phosphorus binders prescribed the most (73.5% and 75.6% in HD and PD, respectively), being less frequent in patients with patients with aCKD (39.9%) and only 4.5 % in KT.

Conclusions: The objectives of the Spanish nephrologists are in line with those recommended by the national and international clinical guidelines; however, there is still a wide room for improvement to achieve these goals, especially in HD and PD patients.