Achievement of 2009 and 2017 Kidney Disease: Improving Global Outcomes mineral and bone targets and survival in a French cohort of chronic kidney disease Stages 4 and 5 non-dialysis patients.

Background: The aim of the third French Phosphorus and Calcium Observatory (Photo-Graphe® 3) was to assess the achievement of international Kidney Disease: Improving Global Outcomes (KDIGO) recommendations on optimal serum phosphate, calcium and parathyroid hormone (PTH) levels and possible associations with mortality in patients with chronic kidney disease (CKD).

Methods: This was a prospective, observational study conducted with nephrologists in France who were selected using a clustering approach. Adult patients with non-dialysis Stage 4 or 5 CKD and no kidney graft history were eligible. Data about clinical events, serum biochemistry and treatment were collected every 6 months for 2.5 years and 12 months thereafter. The Kaplan-Meier method was used for survival analysis and Cox proportional hazards model for identification of factors associated with survival.

Results: Overall, 566 CKD Stage 4 patients (men, 56%) and 153 CKD Stage 5 patients (men, 62%) were included. In Stage 4, only 14-15% patients achieved the three main 2009 KDIGO targets during the first 2 years and 22% at 2.5 years. In Stage 5 patients, the proportion remained <6% throughout. The percentages of patients achieving the three main 2017 KDIGO targets were slightly higher at each time point. Overall, 14% of Stage 4 and 10% of Stage 5 patients died in the observation period. Only age and haemoglobin level were significantly associated with risk of all-cause mortality.

Conclusions: Few CKD patients achieved KDIGO mineral targets. Increased mortality risk was linked to older age and lower haemoglobin level, but not to serum calcium, phosphate or PTH targets.