Trends and Variations in Intravenous Vitamin D Use among Hemodialysis Patients in the United States

Injectable vitamin D agents are commonly used to manage secondary hyperparathyroidism in dialysis patients. Yet, there are few data documenting the trends and geographic variations in the use of these agents in large, representative samples. We sought to describe patterns and variations in the use of vitamin D formulations (calcitriol, paricalcitol, and doxercalciferol) in hemodialysis patients. We studied patients in the United States Renal Data System between January1999 and December 2008 with Medicare as a primary payer. Annual percentages of patients treated with each type of formulation were tabulated by race, sex, and age at dialysis initiation. The geographical distribution of vitamin D dose per patient was mapped at the state level. Intravenous vitamin D use has increased sharply from 1999 to 2008 with 83.9% of patients treated with any vitamin D formulation in 2008. The use of calcitriol has declined since 1999, going from being administered in 58.6% of patients in 1999 to 1.8% in 2008. Paricalcitol was found to be the overwhelmingly preferred formulation during the study years. In 2008, the average dose among black patients was 84% greater than among white patients (136 mcg vs. 73.6 mcg). Higher doses of vitamin D were administered to patients in the southern region of the country. Vitamin D use has increased and parallels the rise in use of paricalcitol and doxercalciferol. Given the variations in use and known pharmacologic differences in vitamin D formulations, future research should focus on whether the formulations differentially affect patient outcomes

Estimated Impact of Targeted Pre-Exposure Prophylaxis: Strategies for Men Who Have Sex with Men in the United States

Pre-exposure prophylaxis (PrEP) effectively reduces human immunodeficiency virus (HIV) transmission. We aimed to estimate the impact of different PrEP prioritization strategies among Black and Latino men who have sex with men (MSM) in the United States, populations most disproportionately affected by HIV. We developed an agent-based simulation to model the HIV epidemic among MSM. Individuals were assigned an HIV incidence risk index (HIRI-MSM) based on their sexual behavior. Prioritization strategies included PrEP use for individuals with HIRI-MSM ≥10 among all MSM, all Black MSM, young (≤25 years) Black MSM, Latino MSM, and young Latino MSM. We estimated the number needed to treat (NNT) to prevent one HIV infection, reductions in prevalence and incidence, and subsequent infections in non-PrEP users avoided under these strategies over 5 years (2016−2020). Young Black MSM eligible for PrEP had the lowest NNT (NNT = 10) followed by all Black MSM (NNT = 33) and young Latino MSM (NNT = 35). All Latino MSM and all MSM had NNT values of 63 and 70, respectively. Secondary infection reduction with PrEP was the highest among young Latino MSM (53.2%) followed by young Black MSM (37.8%). Targeting all MSM had the greatest reduction in prevalence (14.7% versus 2.9%−3.9% in other strategies) and incidence (49.4% versus 9.4%−13.9% in other groups). Using data representative of the United States MSM population, we found that a strategy of universal PrEP use by MSM was most effective in reducing HIV prevalence and incidence of MSM. Targeted use of PrEP by Black and Latino MSM, however, especially those ≤25 years, had the greatest impact on HIV prevention