Outpatient Parenteral Antimicrobial Therapy at Large Veterans Administration Medical Center | Page 3
Published Online: September 13, 2013
Andrew Lai, MD; Thuong Tran, PharmD; Hien M. Nguyen, MD; Jacob Fleischmann, MD; David O. Beenhouwer, MD; and Christopher J. Graber, MD, MPH
Of our 6 major line-related complications, an organism was isolated from the bloodstream in 5 cases: vancomycinresistant Enterococcus facecium, Staphylococcus epidermidis, Candida albicans, Klebsiella species, and Enterococcus faecalis. In the sixth case, CR-BSI was diagnosed based on high clinical suspicion despite no bloodstream isolate (possibly due to prior administration of antibiotics). In 2 cases, it was not clear whether bacteremia stemmed from a PICC line or hemodialysis catheter. Because CR-BSI due to PICC line could not be ruled out in either instance, these episodes were designated as major line-related complications. All 6 patients had their PICC and/or hemodialysis catheters removed, and all but 1 had their intravenous antimicrobials discontinued. All in all, rates of PICC complications decreased from 2006 to 2009 (8.4% to 4.5%), though the c2 test for trend was not significant.
Of 393 courses of OPAT, 313 were completed, giving an overall completion rate of 79.6%. Of the 80 patients with incomplete treatments, 49 were readmitted, and 1 patient was admitted to an outside facility and died of unknown causes before completing OPAT treatment as described above. In all cases of incomplete treatment due to readmission, the patient received appropriate intravenous antibiotics while hospitalized and the need for further antimicrobial therapy was assessed by the OPAT team at time of discharge. Of the remaining 30 noncompletions of OPAT, 20 were changed early to oral antibiotics, 8 had antibiotics discontinued altogether, and 2 were changed to a different OPAT regimen (Table 3). To determine whether any factors were associated with noncompletion of OPAT, we performed bivariate logistic regression using most of the demographic data from Table 1 and the clinical diagnosis and antibiotic data from Table 2. Those factors that approached or met statistical significance included bacteremia (odds ratio [OR] = 1.82; P = .040), concomitant congestive heart failure (OR = 1.64; P = .051), and concomitant ESRD (OR = 2.59; P = .015). When these 3 variables were combined in a multivariable model, only ESRDremained significantly associated with OPAT noncompletion (OR = 2.20; P = .047).
Informal Cost Analysis
The total cost of OPAT was $2,178,569 ($450,934 for antibiotics provided by contracted pharmacy plus $832,200 in per diem pharmacy charges plus $895,435 in per diem nursing charges). Projected inpatient cost savings were calculated by adding what our OPAT antibiotics would have cost if they had been given in an inpatient setting (we calculated this figure to be $234,637; VA prices are generally lower than contract pharmacy prices) to the estimated cost of continued hospitalization (average daily bed cost multiplied by total hospital days). Creating estimations regarding hospital days saved can be problematic, as patients who remain hospitalized (as opposed to receiving OPAT) may theoretically transition to oral therapy at some point and/or be discharged home. However, we can infer that patients are enrolled into OPAT specifically because an infectious diseases specialist has determined that the patient requires intravenous antibiotics for the duration of their treatment. We made the crude assumption that each day of outpatient therapy represented 1 saved day of hospitalization; using that metric, OPAT was responsible for a reduction of 8322 days in additional hospitalization over 4 years. Our hospital administrators estimate that a day of inpatient hospitalization costs $2198. Thus, a total of $18,526,393 (8322 days –$2198 per day + $234,637 in drug costs) in hospitalization costs were potentially averted. As such, overall estimated cost savings with OPAT were $16,347,824 ($4,086,956 per year, $41,598 per OPAT episode).
In this retrospective study, we demonstrate that OPAT can be delivered effectively and safely for a cohort of patients with a high acuity of illness, advanced age, and multiple baseline comorbidities. Our completion rate of ~80% is lower than that reported in other data sets, which is likely a result of the high number of all-cause hospital readmissions. All readmitted patients were evaluated by the OPAT service upon discharge, and there was significant heterogeneity in treatment course postdischarge (eg, continuation of OPAT, transition to oral therapy) depending on length of hospital stay or change in clinical status. Therefore, we considered all patients who were readmitted (regardless of cause) to have incomplete treatment. A significant number of patients were admitted because of “failure to improve” on OPAT; however, given the significant baseline comorbidities of our patient population, it is possible that many of these cases represent the natural progression of a disease state and not treatment failure per se.
PDF is available on the last page.