Impact of Substance Use Disorders on Outcomes of Medically Insured Persons Receiving Multiweek Outpatient Parenteral Antimicrobial Therapy: a Claims-based Cohort Study From 2015 to 2020.

Background: Outpatient parenteral antimicrobial therapy (OPAT) is often withheld from individuals with substance use disorder (SUD), despite evidence suggesting similar outcomes. We investigated this using a large, nationwide claims database.

Methods: We analyzed Merative MarketScan (2015-2020) data to identify adults treated with intravenous vancomycin, daptomycin, nafcillin, oxacillin, or cefazolin for ≥7 days after hospitalization. Patients with end-stage renal disease or Clostridioides difficile were excluded. SUD was defined using pre-discharge International Classification of Diseases 10-CM codes. Rates of overdose, central venous catheter (CVC) events during OPAT, and 90-day all-cause readmissions following OPAT completion were compared between patients with and without SUD, adjusting for confounders via multivariable logistic regression.

Results: Among 5903 patients, 18% had SUD. These patients were younger, less often male, and less likely discharged home. Unadjusted rates of 90-day readmission (40.1% vs 32.5%, P < .001) and overdose (1.2% vs 0.1%, P < .001) were higher in the SUD group, whereas CVC event rates were similar (6.5% vs 5.3%, P = .137). However, adjusted analyses revealed SUD was not significantly associated with readmission (odds ratio [OR] 1.16, P = .067) or CVC events (OR 1.10, P = .552), but was associated with higher odds of overdose (OR 6.03, P < .001). Readmission was predicted by insurance type, mental health disorders, and infection type. CVC events were associated with infection type and discharge to home.

Conclusions: SUD was not independently associated with increased 90-day readmission or CVC event risk, but was a significant risk factor for overdose, supporting harm reduction approaches over exclusion from OPAT based on SUD status.