Free surgery & anesthesia tool
Apfel Score Calculator for PONV Risk
The Apfel score predicts postoperative nausea and vomiting (PONV) risk by counting four factors, one point each: female sex, non-smoking, a history of PONV or motion sickness, and expected postoperative opioids. In the original 1999 study, PONV incidence with 0, 1, 2, 3 or 4 factors was 10%, 21%, 39%, 61% and 79%. Tick the factors below to get your score.
Prepared by Prospyr · Reviewed October 3, 2026 · Free, no sign-up, runs in your browser
Tick each Apfel risk factor that applies (1 point each)
Four factors from Apfel et al., 1999, for adults having surgery under inhalational anesthesia.
Apfel score
0of 4
PONV incidence in the study: 10%
Of adults with 0 risk factors in Apfel et al., about 10 in 100 had nausea or vomiting within 24 hours of surgery.
Decision support only; it does not replace clinical judgment. Published group incidence in patients who received no antiemetic prophylaxis, not a prediction for one patient. This tool does not recommend any drug or approach.
Apfel score calculator: the four PONV risk factors
One point for each factor, so the total runs from 0 to 4.
| Factor | Counts as 1 point when |
|---|---|
| Female sex | Patient is female. |
| Non-smoker | Patient does not smoke. |
| History of PONV or motion sickness | Previous postoperative nausea and vomiting, or a history of motion sickness. |
| Postoperative opioids expected | Opioids are expected to be used after surgery. |
PONV risk by Apfel score
These are the incidences Apfel et al. reported in the combined data set. PONV meant nausea or vomiting within 24 hours of surgery. Patients received inhalational anesthesia without antiemetic prophylaxis.
| Risk factors present | PONV incidence |
|---|---|
| 0 | 10% |
| 1 | 21% |
| 2 | 39% |
| 3 | 61% |
| 4 | 79% |
The study also showed that the risk scores from one center predicted PONV at the other (AUC 0.65 to 0.75), and that simplifying to a count of factors did not meaningfully weaken the discrimination (AUC 0.63 to 0.73).
Worked example
A 34-year-old woman who does not smoke and gets motion sick on long drives is having a procedure under general anesthesia, and the plan includes postoperative opioids. Female (1) + non-smoker (1) + motion sickness (1) + opioids (1) = 4, which matches the 79% incidence in the study. Take away the opioids and the score is 3, which matches 61%. A 45-year-old male smoker with no history and no opioids scores 0, matching 10%.
PONV risk in aesthetic and plastic surgery practices
In an aesthetic practice it is easy for a patient to count three or four Apfel factors: female, non-smoker, a history of motion sickness or PONV, and postoperative opioids in the plan. The score is a quick way to document risk at the preoperative visit. It describes the likelihood of PONV; it does not say what to do about it.
Prospyr's digital intake can collect motion sickness, smoking and prior anesthesia history before the visit, and charting keeps the score with the record. See also the STOP-Bang calculator and the ASA physical status classification.
Frequently asked questions
What is the Apfel score?
The Apfel score is a four-factor risk score for postoperative nausea and vomiting (PONV) in adults. Apfel and colleagues published the simplified version in Anesthesiology in 1999 after testing it across two centers. The four factors are female gender, history of motion sickness or PONV, non-smoking, and the use of postoperative opioids.
How is the Apfel score calculated?
Give one point for each factor that is present and add them, for a total of 0 to 4. A non-smoking woman with a history of motion sickness who is expected to need postoperative opioids scores 4. A male smoker with no history and no expected opioids scores 0.
What does an Apfel score of 2 mean?
In the Apfel study, 39% of adults with two risk factors had nausea or vomiting within 24 hours of surgery. The full set of incidences is 10% for 0 factors, 21% for 1, 39% for 2, 61% for 3 and 79% for 4. These are group figures from patients who received no antiemetic prophylaxis.
What is the PONV risk with an Apfel score of 4?
The study reported 79% incidence of PONV with all four factors. That is the highest category in the simplified score. It was measured in adults who had inhalational anesthesia and received no antiemetic prophylaxis.
Does the Apfel score apply to every patient?
It was developed in adult patients having inhalational anesthesia for various types of surgery at two centers, Oulu in Finland (520 patients) and Wuerzburg in Germany (2,202 patients). PONV was defined as nausea or vomiting within 24 hours. Its discriminating power was moderate, with areas under the ROC curve of 0.63 to 0.73 for the simplified score, so it ranks risk rather than predicting individuals.
Is smoking a risk factor for PONV?
In the Apfel score, non-smoking is the risk factor: non-smokers had a higher PONV risk than smokers. That is why a patient who does not smoke gets the point.
Does this tool recommend antiemetics?
No. It counts the four factors and shows the published incidence. It does not suggest a drug, a dose or an anesthetic technique. Those choices belong to the anesthesia provider and your protocol.
Sources and scope
- Apfel CC, Laara E, Koivuranta M, Greim CA, Roewer N. A simplified risk score for predicting postoperative nausea and vomiting: conclusions from cross-validations between two centers. Anesthesiology 1999;91:693-700
The four predictors, the study populations and the PONV incidences of 10%, 21%, 39%, 61% and 79% for 0 to 4 factors.
Decision support only; it does not replace clinical judgment. This calculator counts four published factors and shows the incidence reported in one study. It does not recommend any drug, dose or anesthetic technique.