Comparing a Procalcitonin‐Based Guideline to the IDSA/ATS 2007 Pneumonia Guideline: A Cost Minimization Analysis

Background:

Community‐acquired pneumonia is a clinical diagnosis determined by the presence of respiratory signs and symptoms. Unfortunately, these clinical findings are not specific and may represent manifestations of other conditions. In addition, pneumonia may be caused by bacterial or viral pathogens. which leads to uncertainty about the appropriateness of antibiotic usage. Given this diagnostic uncertainly, other adjuvant tests, especially biomarkers, have been examined to guide appropriate and timely antibiotic delivery to patients with suspected bacterial pneumonia. The biomarker procalcitonin (PCT), when used to guide initiation and managemenl of antibiotic usage, decreased antibiotic exposure and antibiotic associated adverse effects while preserving outcomes in a recent study. Assuming the reliability of the study's finding of clinical noninfenority, we conducted a cost minimization analysis to assess cost outcomes, length of stay (LOS), and antibiotic usage of the study's PCT guided treatment strategy compared to an IDSA/ATS guided strategy.

Methods:

The model was designed from the perspective of an 897‐bed urban academic hospital. A semi‐Markov decision model, stratified by Pneumonia Severity Index (PSI) scores of III, IV, and V, was used to estimate the cost, LOS, and antibiotic usage for each strategy. Cost data were estimated from databases developed by the University HealthSystem Consortium (alliance of 104 academic medical centers). PCT and clinical data were derived from published literature. We used the Red Book for average wholesale prices for antibiotics. The model evaluated patients aged 18‐85 with a time horizon of 26 inpatient days, given the extent of clinical resolution data reported from the PORT cohort.

Results:

PCT‐guided therapy yielded an expected cost value of $16,000 as compared to $19,000 for the IDSA‐ATS guideline guided therapy. The PCT guideline also resulted in lower LOS: 6.81‐7.47 days. Days of antibiotic exposure were also lower in the PCT‐guided strategy: 3.43‐7.82. These results assumed an average cost for patients with presumed viral pneumonia (initial PCT levels below the treatment threshold) of $11,000 and a LOS of 5.21 days. A sensitivity analysis of the average cost and LOS of patients with presumed viral pneumonia revealed the IDSA‐ATS‐guided therapy would yield lower expecled cost values at a threshold of $18,000, and a lower LOS if the presumed viral pneumonia patients had a LOS of 6.7 days or greater. Better disaggregation of hospital costs and the determination of PCT kinetics stratified by PSI scores would improve this model's validity.

Conclusions:

Depending on the cost and LOS data of patients with presumed viral pneumonia, PCT‐guided therapy of pneumonia may cost less and decrease LOS.

Author Disclosure:

R. Young, none.