1204. Should Kingella kingae PCR Testing Be Performed in Children Hospitalized with Septic Arthritis?
Session: Poster Abstract Session: Other Bacterial Infections in Children
Saturday, October 22, 2011
Room: Poster Hall B1
Background:  Kingella kingae is a common cause of septic arthritis in young children that is often associated with less severe disease, so early transition to oral therapy may be safe and efficacious in those with established microbiologic diagnosis. Standard culture (SC) has an estimated 33% sensitivity for K. kingae, but the new K. kingae-specific PCR (kPCR) assay has a 99% sensitivity permitting accurate and rapid identification.  Our objective was to determine cost implications associated with use of kPCR testing in children hospitalized with septic arthritis.

Methods: Using published studies and the Kids’ Inpatient Database (KID) for children hospitalized with septic arthritis, we compared SC and SC+kPCR of synovial fluid using a cost minimization decision analysis model from the hospital perspective. The model assumes average length of stay (LOS) for septic arthritis is 6 days; no discharges occur before 48hrs; synovial fluid was obtained within 24 hrs of admission.  Transition to oral therapy with pos SC for Kingella would reduce LOS by 1 day and with pos kPCR would reduce LOS by 2 days. kPCR costs include list price plus shipping.  We assumed earlier discharge or change in therapy occurred only in those with pos kPCR plus clinical course consistent with Kingella. Hence we assumed early discharges have no adverse clinical consequences.

Results:  The base case analysis found mean costs of hospitalization were $9749 for SC versus $8954 for kPCR. In 1-way sensitivity analyses, kPCR remained cost saving when 1) Kingella prevalence (baseline 41%) was >12.5%; 2) kPCR sensitivity (baseline 99%) was >42%; 3) kPCR cost (baseline $350) was <$1145; 4) LOS reduction for kPCR positivity (baseline 2 days versus SC) was > 0.8 days and 5) cost per hospital day (baseline $1691) was >$517.  If kPCR positivity shortened LOS by 3 days, costs savings were $1481.  With perfect SC sensitivity (baseline 33%), kPCR remained less expensive, saving $329 per hospitalization. 

Conclusion: Despite its cost, kPCR for children hospitalized with septic arthritis may be cost-saving depending on the prevalence of Kingella. These results suggest that hospitals should determine local prevalence of K. kingae and consider earlier transition to oral antibiotics for those kPCR positive.

Subject Category: P. Pediatric and perinatal infections

Mark D. Yinger, MD, Stephen G. Pauker, MD and John B. Wong, MD, Division of Clinical Decision Making, Informatics and Telemedicine, Tufts Medical Center, Boston, MA


M. D. Yinger, None

S. G. Pauker, None

J. B. Wong, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.