Risk Factors for Complications during Outpatient Parenteral Antimicrobial Therapy for Adult Orthopedic and Neurosurgical Infections.

Objectives Outpatient parenteral antimicrobial therapy (OPAT) is an effective way of treating infections, but complications are common. We identified patient characteristics and OPAT treatment factors associated with increased risk of OPAT-related complications. Methods We used a retrospective cohort design that assessed 337 adult patients treated with OPAT for orthopedic and neurosurgical infections between August 1, 2008 and May 30, 2010. Independent variables included demographics, infection characteristics, lead time factors, OPAT treatment factors, and comorbid conditions. Multivariable log-binomial regression was used to estimate the risk of OPAT complications. Results The mean patient age was 55 years (range 19-87), 86% had an orthopedic infection, and 44% were treated with intravenous vancomycin. OPAT complications were seen in 45% (152/337) of the cohort. Risk ratios for OPAT complications were 1.9 (95% confidence interval 1.4-2.5) in patients having no primary care provider, 1.7 (95% confidence interval 1.3-2.1) for those treated with vancomycin. Conclusions Identifying specific patient characteristics and OPAT treatment factors could facilitate OPAT process improvements to reduce the risk of OPAT complications for vulnerable patients.