A bedside prediction-scoring model for late-onset neonatal sepsis

Abstract

Objective: Insufficient tools for bedside prediction of late-onset neonatal sepsis (LNS) initiated this study. The objective was to develop and validate a simple prediction-scoring model for LNS defined as culture-proven sepsis occurring 72 hours after birth.

Methods: The study was performed at a university hospital in Bangkok. The derivation phase included medical records of 1870 neonates, randomly selected from 9347 records of neonates who had been hospitalized for >72 hours during 1998 to 2000, of which 1824 records were available. In all, 100 neonates were clinically suspected of sepsis and 17 had proven LNS. The validation phase included 73 neonates suspected of having sepsis during July 2002 to June 2003 and 25 who had LNS. Weighted coefficients from Cox's proportional hazards model and receiver-operating-characteristic (ROC) curve analysis were used.

Results: The incidence density of LNS was 17/11355 (1.5/1000) person-days. A scoring model was developed and consisted of the following: hypotension (score 4), abnormal body temperature (score 3), respiratory insufficiency (score 2), neutrophil band form fraction >1% (score 2), platelet count <150 x 10(3)/microl (score 2), and umbilical venous catheterization (1 to 7 or >7 days; score 2 or 4). The area under the ROC curves for prediction of LNS in a neonate suspected of sepsis in each of the two phases was 0.85 and 0.80, respectively (p=0.436). The mean probabilities of LNS were approximately 0.10 (low risk) for scores from 0 to 3; 0.50 (intermediate risk) for scores from 4 to 6; and 0.70 (high risk) for scores > or =7.

Conclusion: A simple prediction-scoring model for LNS was developed. Validation of the scores suggested good diagnostic performance.