BOSTON – Mandatory assessment protocols for outpatient parenteral antimicrobial therapy appear to be scoring successes in patient selection, based on a single-center, retrospective review of cases deemed inappropriate for the treatment approach.
Appropriate denial of outpatient parenteral antimicrobial therapy (OPAT) and peripherally inserted central catheter (PICC) placement by infectious disease physicians appears to avoid unnecessary antibiotic usage, PICC-line complications, and costs without compromising successful clinical outcomes, Dr. Marjorie Conant said at the annual meeting of the Infectious Diseases Society of America (IDSA).
OPAT is being used more widely because of its potential to reduce morbidity, to allow earlier discharges, to improve quality of life, and to reduce treatment costs. But to be successful, OPAT needs to be directed at stable patients who need long-term antibiotic therapy. To assist in patient selection, IDSA practice guidelines recommend that infectious disease physicians take part in evaluating candidates for OPAT (Clin. Infect. Dis. 2004;38:1651-72), and many hospitals have implemented mandatory assessment protocols.
To date, however, "no published studies have looked at the clinical outcomes of patients who were not approved [for OPAT] or at the economic impact of averted [OPAT]," said Dr. Conant of Indiana University, Indianapolis, who performed such an analysis with coinvestigators at Wishard Health Services and Purdue University, also in Indianapolis.
The researchers reviewed the electronic medical records of patients who were considered for OPAT but were denied by the inpatient infectious disease consult service at Wishard, an inner-city, county teaching hospital. The evaluations took place from 2008 to 2010; children, pregnant women, and incarcerated individuals were not included in the study.
"No published studies have looked at the clinical outcomes of patients who were not approved [for OPAT] or at the economic impact of averted [OPAT]."
Demographic and medical data, including infection- and medication-specific information, were evaluated for each patient. Clinical outcome data at one year following the OPAT denial was used to classify cure rates. "Definitively cured" was defined as a documented clinical or microbiologic cure without recurrence of the infection for up to 1 year. "Probably cured" was presumed eradication of infection and no EMR-documented return visits for continued or worsening infection for up to 1 year. "Treatment failures" were those who experienced worsening or recurrence of the same infection.
The number of patients who experienced each of the clinical outcomes and the total number of patients in whom OPAT was averted were used to determine the overall rate of cure, probable cure, and treatment failure.
Of the 57 patients who met the study’s inclusion criteria, 32 (56%) were categorized as definitive cures, 9 (16%) were probable cures, and 16 (28%) were treatment failures, Dr. Conant reported. The cures and failures had similar rates of obesity, diabetes, and smoking. "Only age was found to be significantly different between patients who experienced clinical cure and clinical failure." Those in the cure group averaged 57 years of age; those in the failure group averaged 46 years.
Of the 16 treatment failures, "only four patients were thought to be true failures," Dr. Conant said. The remaining 12 patients either did not comply with the prescribed oral antibiotic therapy or their underlying disease processes progressed.
Thus, "4 of 57 patients in whom [OPAT] was denied by the infectious disease service experienced a true clinical failure," she said.
OPAT requires placement of a PICC line by an outside contractor, along with confirmatory chest x-ray, at a cost of approximately $1,000/patient, Dr. Conant said. Thus, the preliminary cost analysis suggests that the appropriate denial of 53 PICC lines saved the hospital approximately $53,000.
Further cost analyses are currently underway, she said, noting that when the costs of labs, antibiotics, supplies, and personnel associated with OPAT are included, "the cost savings will increase exponentially," as will the nonmonetary savings, such as reductions in mechanical PICC complications, line infections, Clostridium difficile colitis, and antibiotic resistance.
The study findings are limited by the lack of prospective monitoring of patients who were denied OPAT and the possibility that "probable cure" patients may have sought and received treatment for worsening infections that were not detected through the EMR review, Dr. Conant said.
Dr. Conant had no relevant financial conflicts to disclose.