Mineral and bone disorders outcomes study for Japanese chronic kidney disease stage 5D patients: rationale and study design.

Secondary hyperparathyroidism is common in patients with mineral and bone disorders related to chronic kidney disease. Guidelines for the management of secondary hyperparathyroidism in hemodialysis patients have been promulgated, but evidence on the relationship between treatment and survival is still insufficient. Studying hemodialysis patients with secondary hyperparathyroidism, we have three goals: (i) to record the characteristics of those patients and variations in the patterns of their treatment; (ii) to analyze factors associated with variations in those medical practice patterns; and (iii) to identify the practice patterns and other factors that affect hospitalization, mortality, and other patient-level outcomes. This is a three-year prospective observational study with a case-cohort and a cohort design. Eligible patients comprise all patients who are receiving hemodialysis at the participating facilities and who also have secondary hyperparathyroidism. In the case-cohort study, the outcomes are relatively infrequent events (all-cause mortality and cardiovascular mortality). The cohort study will include a randomly selected sample of 40% of all study participants; and the outcomes include hospitalization, parathyroid interventions, bone fracture, and mineral bone density management status. Explanatory variables comprise medications and other factors likely to be associated with the outcomes of dialysis and of secondary hyperparathyroidism, and facility-level practice patterns. We expect this study to provide evidence regarding factors that affect outcomes in hemodialysis patients with secondary hyperparathyroidism.