Effect of an evidence-based hand washing policy on hand washing rates and false-positive coagulase negative staphylococcus blood and cerebrospinal fluid culture rates in a level III NICU.

OBJECTIVE: To determine the effect of implementing an evidence-based hand washing policy on between-patient hand washing compliance and on blood and cerebrospinal fluid (CSF) culture rates in a level III neonatal intensive care unit (NICU).

METHODS: An evidence-based hand washing policy, supported by an intensive education program, was introduced in a regional NICU. A total of 2009 preintervention neonates (16,168 patient days) over 17 months were compared to 676 postintervention neonates (5779 patient days) over 6 months. Hand washing compliance and rates of blood and CSF cultures yielding coagulase negative staphylococci (CONS) were compared before and after intervention.

RESULTS: Compliance with appropriate between-patient hand washing improved (from 47.4% to 85.4%, p=0.001) after the hand washing policy was introduced. The rate of cultures positive for CONS declined from 6.1+/-2.3 to 3.2+/-1.6 per 1000 patient days (p=0.005). Most of this reduction was attributable to a reduction in false-positive cultures, from 4.2+/-2.4 to 1.9+/-1.8 per 1000 patient days (p=0.042), but there was a trend toward decreased true-positive cultures (from 2.1+/-1.2 to 1.2+/-1.0 per 1000 patient days, p=0.074) as well. Potential confounders and demographics factors were similar between the control and intervention subjects.

CONCLUSION: Implementation of an evidence-based hand washing policy resulted in a significant increase in hand washing compliance and a significant decrease in false-positive coagulase negative staphylococcal blood and CSF culture rates. Exploratory data analysis revealed a possible effect on true-positive coagulase negative staphylococcal blood and CSF culture rates, but these results need to be confirmed in future studies.