Organizational status of dialysis facilities and patient outcome: does higher injectable medication use mediate increased mortality?

Abstract

Objective: Examine the mediating effect of injectable drugs in the relationship between dialysis facility organizational status and patient mortality.

Study setting: Medicare dialysis population.

Study design: Data from the U.S. Renal Data System (USRDS) were used to identify 3,884 freestanding dialysis facilities and 37,942 Medicare patients incident to end-stage renal disease (ESRD) in 2006. The role of injectable medications was evaluated during a 2-year follow-up period by mediational analyses using mixed-effect regression models.

Data collection: USRDS data were matched with Dialysis Facility Report data from Centers for Medicare and Medicaid Services (CMS) and census data.

Principal findings: There was a strong association found between organizational status and use of injectable drugs. Large for-profit chains used significantly higher injectable medications compared with nonprofit chains and independent facilities. However, the relationship between facility organizational status and patient mortality was not found to be mediated through the higher use of injectable drugs.

Conclusions: Large for-profit chain facilities administered higher IV epoetin, iron, and vitamin D dosages, but this did not result in improved survival. Given the associated costs and lack of a survival benefit, the overuse of injectable medications among the U.S. dialysis patients will likely end under the recent bundling of injectable medications without jeopardizing patient outcomes.

Figure 1

Adjusted Difference in Mean Dose between All Facility Types and Chain 4 with Ninety-Five Percent Confidence Interval (Model 2 Results) Note. FP, for-profit; NP, nonprofit. Grid line across zero can be considered as reference line (Chain 4). Points above the line indicate higher doses than Chain 4. Points below the line indicate lower doses than Chain 4.