Background: Available tests to diagnose infection in neonates often provide results after 12-24 hours. A bedside test that is reliable will facilitate earlier exclusion or diagnosis of infection.
Objective: To validate a bedside C-reactive protein (CRP) test against the currently available laboratory CRP test in neonates with suspected sepsis.
Methods: This was a prospective observational study where a bedside CRP was done concurrently with and validated against a laboratory CRP in neonates with suspected sepsis. The sensitivities, specificities and predictive values for the bedside CRP tests were calculated using the laboratory CRPs as the reference test.
Results: There were 209 measured CRP-sample pairs. Seventy per cent of these had suspected early-onset neonatal sepsis and 30% had suspected late-onset neonatal sepsis. Twelve per cent had culture-proven sepsis. At the recommended cut-off of 8.0 mg/L for the bedside CRP test, the sensitivity, specificity, positive and negative predictive values were 84%, 80%, 30% and 97%, respectively. Adjusting the cut-off value from 8.0 to 15.0 mg/L improved the specificity to 88%. The sensitivity, specificity and positive and negative predictive values were not different between early-onset and late-onset sepsis. The receiver operating characteristic curve had an area below the curve of 0.84 for the cut-off at 16.2 mg/L on the beside CRP test.
Conclusions: The bedside CRP test may be used as a screening test to aid decisions to either commence or discontinue antibiotics in circumstances where the clinical diagnosis of sepsis is in doubt. By using a cut-off of 16.0 mg/L for the bedside CRP test, the possibility of a false negative result is minimised.