PURPOSE: To compare two of the latest published scores for predicting 
postoperative nausea and vomiting (PONV) in potentially high-risk patients.
METHODS: Adult in-patients scheduled for throat, thyroid, breast or 
gynecological surgery under general inhalational anesthesia were studied 
prospectively over 24 hr for PONV. The latest published score considers four 
risk factors: female gender, previous history of PONV or motion sickness, 
non-smoking status and postoperative use of opioids (Apfel-score). The 
previously published score includes, in addition to these factors, duration, 
type of anesthesia and surgery (Sinclair-score). The two scores were compared by 
calculating the area under a receiver operating characteristic (ROC)-curve and 
plotting calibration curves of the predicted and the observed incidence of PONV.
RESULTS: Five hundred consecutive patients were studied and patients who 
received prophylactic antiemetics were excluded. Of the remaining 428 patients 
49.5% suffered from PONV. Multivariable analysis revealed that age, gender, 
previous history of PONV or motion sickness and postoperative use of opioids had 
an impact on PONV. The area under the ROC-curve was significantly greater for 
the Apfel-score compared to the Sinclair-score (0.71 vs 0.64, P=0.008). The 
correlation between the predicted (x) and the observed (y) incidence for the 
Apfel-score and for the Sinclair-score was y=1.08x - 0.07 and y=0.93x + 0.27.
CONCLUSION: In our hospital, the simplified Apfel-score presented with 
favourable discriminating and calibration properties for predicting the risk of 
PONV. Therefore, we have implemented this score in our daily clinical practice 
as well as in an ongoing antiemetic trial.