Low Use of Outpatient Parenteral Antimicrobial Therapy for Drug Use-Associated Infective Endocarditis in an Urban Hospital System

Background. The opioid crisis in the United States has led to increasing hospitalizations for drug use-associated infective endocarditis (DUA-IE). Outpatient parenteral antimicrobial therapy (OPAT), the preferred modality for intravenous antibiotics for infective endocarditis, has demonstrated similar outcomes among patients with DUA-IE versus non-DUA-IE, but current studies suffer selection bias. The utilization of OPAT for DUA-IE more generally is not well studied. Methods. This retrospective cohort study compared OPAT use for DUA-IE versus non-DUA-IE in adults hospitalized between January 1, 2015 and September 1, 2019 at 3 urban hospitals. We used multivariable regression analysis to assess the association between DUA-IE and discharge with OPAT, adjusting for clinically significant covariables. Results. The cohort included 518 patients (126 DUA-IE, 392 non-DUA-IE). Compared to those with non-DUA-IE, DUA-IE patients were younger (53.0 vs 68.2 years, P < .001) and more commonly undomiciled (9.5% vs 0.3%, P < .01). Patients with DUA-IE had a significantly lower odds of discharge with OPAT than non-DUA-IE patients (adjusted odds ratio [aOR] = 0.20; 95% confidence interval [CI], 0.10-0.39). Odds of discharge with OPAT remained lower for patients with DUA-IE after excluding undomiciled patients (aOR = 0.22; 95% CI, 0.11-0.43) and those with patient-directed discharges (aOR = 0.27; 95% CI, 0.14-0.52). Conclusions. Significantly fewer patients with DUA-IE were discharged with OPAT compared to those with non-DUA-IE, and undomiciled patients or patient-directed discharges did not fully account for this difference. Efforts to increase OPAT utilization among patients with DUA-IE could have important benefits for patients and the healthcare system. Keywords. endocarditis; OPAT; opioid use disorder; substance use disorder.