Cost analysis of enteroviral polymerase chain reaction in infants with fever and cerebrospinal fluid pleocytosis

Background: Infants with fever and cerebrospinal fluid (CSF) pleocytosis are routinely admitted to the hospital for parenteral antibiotic therapy for potential bacterial meningitis pending results of CSF culture. Published estimates suggest that 90%;, of all episodes of meningitis are caused by enterovirus. Enteroviral polymerase chain reaction (ePCR) has a sensitivity of 92% to 100% and a specificity of 97% to 100% in CSF. Objective: To compare a management strategy using ePCR with current practice to determine potential savings by allowing earlier discharge. Methods: Decision analysis comparing 2 strategies for the care of a retrospective cohort of infants with fever and CSF pleocytosis: standard practice vs ePCR testing of all CSF samples. Model assumptions include the following: (1) standard practice patients continue parenteral antibiotic therapy until CSF cultures are negative at 48 hours, (2) patients with positive ePCR results would be discharged after 24 hours, (3) patients with positive ePCR results have a negative CSF culture, and (4) costs are calculated from actual patient charges with a cost-to-charge ratio of 0.65. Subjects: All infants aged 28 days to 12 months admitted to an urban teaching hospital with fever, CSF pleocytosis, and a negative CSF Gram stain from January 1996 through December 1997. Outcome Measure: Total cost of hospitalization. Results: A total of 126 infants were identified. One hundred twelve (89%) were discharged with a diagnosis of aseptic meningitis; 72% of these cases occurred during the peak enterovirus season (June to October). Three of 3 patients with positive CSF cultures had bacterial growth within 24 hours of admission. Mean length of stay for patients with aseptic meningitis was 2.3 days (SD, +/-1.4 days). Total cost of hospital care for all 126 infants was $381145. In our patient population, total patient costs would be reduced by the ePCR strategy if enterovirus accounts for more than 5.9% of all meningitis cases. Varying the sensitivity of the ePCR assay from 100% to 90% changes the "breakeven" prevalence from 5.8% to 6.5%. Total cost savings of 10%, 20%, and 30% would occur at an enteroviral meningitis prevalence of 36.3%, 66.7%, and 97.1%, respectively. Conclusions: Enteroviral PCR analysis of CSF for infants admitted to the hospital with meningitis can result in cost savings when the prevalence of enteroviral meningitis exceeds 5.9%. limiting use of ePCR to the enterovirus season would increase cost savings. A prospective study is needed to validate these results.