Lay summary
Over 4500 New Zealanders live with kidney failure requiring treatment with dialysis or a kidney transplant. Although dialysis is life-sustaining, the death rate is unacceptably high at 13 per 100-person-years. Kidney failure disproportionately affects Maori and Pacific patients. Despite the fact that dialysis costs 1% of the annual New Zealand health budget, the mortality for dialysis patients is 100 times higher than the general population. Kidney failure leads to accumulation of phosphate in blood vessels and body tissues and increases risks of death. Phosphate binders reduce phosphate absorption from the gut to lower blood phosphate levels. Despite >100 previous trials, the evidence that phosphate binders improve patient-centred outcomes is of low certainty. The PHOSPHATE trial is a pragmatic, multi-national randomized trial evaluating whether intensive reduction of serum phosphate levels improves cardiovascular outcomes and mortality for dialysis patients compared to a higher serum phosphate target level.