LAUSR

To the Editor—We read with interest the article by Buehrle et al. outlining their experience with injecting drug users (IDUs) on an outpatient parenteral intravenous (IV) therapy (OPAT) program and believe that it adds much needed evidence to evaluate the place of OPAT for IDUs [1]. We question whether a number of the definitions of failure included in the study, eg, antibiotic noncompliance or missed doses, noncompliance with follow-up clinic appointments, are a true reflection of the success of OPAT. Our service defines success as completion of an OPAT course with measurable signs of clearance of infection regardless of whether a patient has had an episode of noncompliance during the treatment course. It is worthwhile to note that noncompliance is not specific to IDUs on OPAT programs due to the freedom of movement and choice inherent in home treatment that is not available when confined to a hospital bed. We have therefore compared outcomes of our cohort of both IDU and non-IDU OPAT patients, all of whom receive OPAT in the home environment. In our service, IDU OPAT patients have their antibiotics administered by visiting nurses so that their catheter can be monitored, whereas 50% of non-IDU OPAT patients are taught to self-administer. Since 1995, our service has managed 159 IDUs receiving OPAT for bone and joint infections (51.8%), endocarditis (21.6%), bacteremia (11.1%), abscess (including lung, liver, epidural abscess; 7.4%), skin and soft tissue infections (2.5%), and other infections (5.5%), eg, mycotic aneurysm, infected cranioplasty, empyema, neurosyphilis, pneumonia, infected pacemaker leads. In IDUs, the OPAT was administered through PICC lines in 88.6%, subclavian central venous catheters in 9.5%, or implantable port in 1.9%. IDU patients were more likely to be male, with a lower median age, and have a longer stay on OPAT than the non-IDU cohort (Table 1). Compared with non-IDUs, current IDUs (reported use in the last 3 months) were 16.4 times more likely to be noncompliant during OPAT (95% confidence interval [CI], 6.2–43.4; P ≤ .001), recent IDUs (reported use between 4 months and 2 years prior to OPAT) were 14.3 times more likely to be noncompliant (95% CI, 3.25–62.63; P ≤ .001), and those reporting distant use (more than 2 years from the start of OPAT) were 7.7 times more likely to be noncompliant (95% CI, 2.3–25.55; P ≤ .001). Despite the episodes of noncompliance on OPAT, IDUs were less likely to be discharged early from the OPAT program due to a complication, and only 1 IDU was readmitted to the hospital. Overall, 98% of IDUs completed their OPAT course. They were more likely to use the after-hours on-call nurse for a telephone consultation and significantly more likely to require an after-hours call out to troubleshoot a catheter complication. There was no statistical difference between IDUs and non-IDUs when comparing catheters removed for any complication (P = .31); however, current users had a hazard ratio of 2.4 for line failure (95% CI, 1.23–4.64; P = .01). In C O R R E S P O N D E N C E