Cost analysis of an adult outpatient parenteral antibiotic therapy (OPAT) programme - A Canadian teaching hospital and ministry of health perspective

Background: Outpatient parenteral antibiotic therapy (OPAT) programmes have become prevalent over the past 2 decades. From the US perspective, these programmes have been shown to reduce healthcare costs. No comprehensive analysis has been published from the Canadian perspective. Objective: To describe a Canadian OPAT programme for the 3-year period since its inception and to conduct a treatment cost analysis. Design and methods: Demographics and resource utilisation data (health professional labour, laboratory acid diagnostic tests, antimicrobials, delivery, home nursing care, catheters and catheter placement) were prospectively collected for enrollees in the OPAT programme over the evaluation period. Avoided hospital resource utilisation was estimated via retrospective chart review by the investigators. Costs were retrospectively assigned to each resource and total cost avoidance by the OPAT programme was determined from each perspective. Perspective: A teaching hospital and a provincial Ministry of Health (MOH). Main outcome measures and results: 140 treatment courses were initiated for 117 adult patients (mean age 54 years) who were enrolled into the programme. Mean pre-OPAT length of hospital stay was 12 days, and mean OPAT duration was 22.5 days. Bone/joint (39%), skin and soft tissue (16%), cardiac (13%) and respiratory tract (12%) infections were the most common infections managed. The most commonly used antimicrobials were vancomycin (29%), cloxacillin +/- gentamicin (22%) and ceftriaxone +/- gentamicin (11%). 85% of enrollees successfully completed their planned antimicrobial treatment regimens. Premature discontinuation of antimicrobial therapy for various reasons occurred in the remaining 15% of courses. The mean cost per treatment course of OPAT was 1910 Canadian dollars ($Can) from the hospital perspective and $Can6326 from the MOH perspective. Assuming that patients would have otherwise completed their antimicrobial therapy in hospital, the mean cost per treatment course was estimated to be $Can 14 271. The overall cost avoidance of the OPAT programme was $Can 1 730 530 (hospital perspective) and $Can1 009 450 (MOH perspective) over the 3-year assessment period. Sensitivity analyses revealed the results to bt: robust to plausible changes. Conclusions: This analysis supports the premise that an adult OPAT programme can substantially reduce healthcare costs in the Canadian healthcare setting.