[Cost benefit analysis of body surface cultures at a neonatal unit]

Infection continues to be a cause of concern in neonatal units. The high cost of the body surface cultures used to study infection and their limited utility is controversial.

The medical records of newborns admitted for suspected infection in 1999 were retrospectively reviewed. Request criteria, cost, and the clinical utility of body surface cultures were analyzed.

In 1999, body surface cultures were requested in 204 newborns admitted to hospital (70 % of all admitted newborns). Of these, six were diagnosed with bacteremia (6.23/1000; 95 % CI: 5.9-6.5). The most frequently isolated microorganisms were Escherichia coli and Streptococcus agalactiae. The total cost of body surface cultures was 6,510.95 euros (1,083,331 pesetas). In 25 % of cases the results of cultures influenced clinical decision making. The cost necessary to obtain clinical repercussion in a patient was 191.50 euros (31,863 pesetas). Requesting two body surface cultures only (otic and umbilical) halved the cost without diminishing their clinical utility.

A considerable percentage of newborns admitted to hospital present suspected infection requiring microbiological studies. Although the cost of body surface cultures is high, the results of these cultures influence diagnostic and therapeutic decisions in a quarter of patients. We do not believe that eliminating the use of these cultures would be beneficial. However, their cost can be reduced by carefully selecting request criteria and by limiting cultures to two samples (otic and umbilical).