Mortality and illicit drug dependence among hemodialysis patients in the United States: a retrospective cohort analysis

BACKGROUND Illicit drug use is common and known to cause and exacerbate a wide spectrum of kidney disease, often leading to end-stage renal disease (ESRD), but little is known about its prevalence or associated mortality among incident hemodialysis patients. METHODS This study is a retrospective cohort analysis using data obtained from the United States Renal Data System. We assembled a cohort of 511,821 incident hemodialysis patients age 20 years and older who initiated hemodialysis between January 1, 2006 and December 31, 2010. Illicit drug dependence was defined by comorbidity on the ESRD Medical Evidence Report (Form CMS-2728). We performed survival analysis to examine the association of drug dependence with overall mortality and mortality due to diagnoses that can be associated with intravenous drug use (drug-sensitive diagnoses) in the first year after initiating hemodialysis. RESULTS Drug dependence was recorded for 1.5 % (n = 7,461). Drug dependence was independently associated with a 1.3-fold and 2.5-fold higher hazard of overall mortality and mortality due to a potentially drug-sensitive diagnosis [adjusted hazard ratio (AHR) 1.34 (1.27-1.41) and 2.54 (2.05-3.14), p < 0.001, respectively]. This association varied significantly by age (pinteraction < 0.001), with a 9-fold higher hazard of mortality due to a potentially drug-sensitive diagnosis among the youngest patients with drug dependence [AHR 9.21 (5.15-16.44), p < 0.001]. CONCLUSION Illicit drug dependence is a burden within the ESRD program and is strongly associated with premature mortality, particularly among younger patients. Targeted intervention is needed to help reduce this burden.