Postoperative nausea and vomiting (PONV) degrades patient experience and 
increases healthcare costs. Estimates of PONV range from 10% to 80%. The Apfel 
Simplified Score is an evidence-based instrument for determining individual risk 
of PONV. Scoring enables anesthesia providers to match antiemetic strategies 
with the calculated risk of PONV. Data were collected across 3 times. After the 
Apfel scoring system was automated into the electronic medical record, providers 
were more likely to increase PONV prophylaxis for patients at highest risk and 
reduce prophylaxis for patients at lowest risk. Rates of PONV remained similar 
at baseline (34.7%) and in the early postimplementation period (38.8%); a modest 
reduction was observed in the final period (26.5%). Intravenous ondansetron, the 
most common antiemetic at baseline, was not available in the early 
postimplementation period, which may partially explain the initial increase in 
PONV. While ondansetron was unavailable, providers began using 3 other 
antiemetics, a practice that persisted once intravenous ondansetron returned. 
The Apfel score is an evidence-based tool that providers can use to reduce the 
risk of PONV. This electronic tool and the reminder cards have been shared 
across the US Military Health System, fostering an organizational culture that 
values targeted prophylaxis for PONV.