Mortality Rates do not Differ among Patients Prescribed Various Vitamin d Agents

Abstract

Background Limited well-controlled research exists examining the impact of different formulations of oral vitamin D on clinical outcomes in dialysis patients, specifically those on peritoneal dialysis. For this retrospective mortality analysis, we compared mortality rates of patients on 3 of the most commonly prescribed vitamin D agents. Methods We examined 2 years (7/1/2008 to 6/30/2010) of oral medication records of peritoneal dialysis patients from a large US dialysis organization. Patients were identified whose physicians prescribed a single form of vitamin D (calcitriol, paricalcitol, or doxercalciferol) for ≥ 90% of all patient-months. We excluded incident patients (< 90 days on dialysis) and patients whose physicians treated < 5 peritoneal dialysis patients at a dialysis facility, and we assessed mortality. Results The analysis inclusion criteria identified 1,707 patients. The subset in this analysis included 12.6% of all prevalent peritoneal dialysis patients and 11.8% of prevalent patient-months. Patients with physicians who predominately prescribed calcitriol had a lower mortality rate: 9.33 (confidence interval (CI) 7.06, 11.60) deaths per 100 patient-years than the doxercalciferol, 12.20 (CI 9.34, 15.06) or paricalcitol, 12.27 (CI 9.27, 15.28) groups. However, these differences were not statistically significant. A Cox proportional hazards model, adjusting for differences in age, vintage, gender, race, body mass index, and comorbidities also showed no significant differences. Conclusions For this peritoneal dialysis population, instrumental variable analyses showed no significant difference in mortality in patients taking the most common oral vitamin D formulations (calcitriol, doxercalciferol, paricalcitol).