Calculate a Caprini VTE risk score from surgical and clinical risk factors, get the DVT and PE risk level, and see the matching prophylaxis guidance.
Caprini VTE Risk Score Formula
The Caprini score is an additive point total. You assign points for age, the type of surgery, and mobility, then add points for every venous, clotting, and medical risk factor that is present, and sum them:
Caprini Score = Age points + Surgery points + Mobility points + Sum of risk-factor points
Variables:
- Age points: 0 for 40 or younger, 1 for 41 to 60, 2 for 61 to 74, and 3 for 75 or older
- Surgery points: 0 for none, 1 for minor surgery under 45 minutes, 2 for a major, laparoscopic, or arthroscopic procedure over 45 minutes, and 5 for elective major lower-extremity arthroplasty
- Mobility points: 0 for normal, 1 for a medical patient on bed rest, and 2 for a patient confined to bed over 72 hours
- Risk-factor points: each condition you check adds 1, 2, 3, or 5 points based on how strongly it raises clot risk. Varicose veins add 1, a central venous catheter adds 2, a personal or family history of clotting adds 3, and a recent stroke or hip fracture adds 5
The calculator runs in two modes. In "Score the risk factors" you set age, surgery, and mobility and check every factor that applies, and the tool adds the points, grades the risk, lists which factors drove the score, and suggests prophylaxis. In "Interpret a known total score" you enter a total you already have and the tool returns the matching risk level. Selecting Female reveals three extra factors for hormone use and pregnancy, and the optional surgical-population setting changes only the threshold the result checks against, not the score itself.
Caprini Score Risk Levels and Suggested Prophylaxis
The total maps to a risk category, and higher totals call for more intensive prevention. The prophylaxis column follows the tiers commonly used for general surgical patients. The risk figures are approximate baseline rates without prophylaxis, so treat them as a rough guide rather than an exact probability.
| Total score | Risk level | Approx. VTE risk | Suggested prophylaxis (general surgery) |
|---|---|---|---|
| 0 | Lowest risk | Under 0.5% | Early frequent ambulation, or mechanical prophylaxis during the stay |
| 1 to 2 | Low risk | About 1.5% | Mechanical prophylaxis (pneumatic compression) during the stay |
| 3 to 4 | Moderate risk | About 3% | Mechanical prophylaxis during the stay |
| 5 to 6 | High risk | About 6% | Pneumatic compression, and consider heparin or LMWH for 7 to 10 days |
| 7 to 8 | High risk | Higher | Pneumatic compression plus heparin or LMWH for 7 to 10 days |
| 9 or more | Highest risk | Highest | Pneumatic compression plus heparin or LMWH for about 30 days, and consider extended prophylaxis after discharge |
The table above assumes general surgery. The threshold that defines very high risk and triggers extended or pharmacologic prophylaxis is not the same for every operation, and this is where the calculator does something most Caprini tools do not: it lets you set the surgical population so the result checks the correct cutoff.
| Surgical population | Very-high-risk threshold | What it means |
|---|---|---|
| General surgery | 5 or more | The standard cutoff for adding pharmacologic prophylaxis |
| Most other surgical groups | 9 or more | A higher bar is used outside general surgery |
| Total joint arthroplasty | 10 or more | Used to pick anticoagulation over aspirin alone |
| Hip fracture | 12 or more | The highest threshold, reflecting an already high baseline risk |
Evidence also suggests the benefit of pharmacologic prophylaxis becomes clearer once the score reaches about 7 in general surgery, which is why a score in the 5 to 6 band is often managed with mechanical prophylaxis first and heparin added only if other risks are present.
Example Problems
Example 1: score the risk factors.
A 68-year-old man has a major open abdominal operation lasting over an hour, has a current cancer, and has a central venous catheter placed. Age 61 to 74 adds 2, the major procedure adds 2, the malignancy adds 2, and the central line adds 2, for a total of 8. A score of 8 falls in the 7 to 8 band, so the result is high risk, which for general surgery calls for pneumatic compression plus low-dose heparin or LMWH. Because 8 is above the general-surgery threshold of 5, stepped-up prophylaxis is clearly indicated.
Example 2: interpret a known total.
A patient is scored at 9 before a total knee replacement. Enter 9 in "Interpret a known total score" and the model returns highest risk, since 9 or more is the top band. Now open the surgical-population setting and choose total joint arthroplasty: its very-high-risk threshold is 10, so a 9 sits just under the cutoff used to step up prophylaxis for joint replacement, even though the same 9 would clear the threshold in general surgery. The population you pick changes how you read the same number.
Frequently Asked Questions
What is a high Caprini score?
For general surgical patients, a score of 5 or more is treated as high to very high risk and usually prompts adding pharmacologic prophylaxis to mechanical methods. A 0 is the lowest risk, 1 to 2 is low, and 3 to 4 is moderate. Keep in mind that the cutoff for very high risk rises for some procedures, reaching 9 for most other surgical groups, 10 for joint replacement, and 12 for hip fracture.
Does a high score mean the patient needs blood thinners?
Not on its own. The Caprini score estimates the risk of clotting, but it does not measure the risk of bleeding. A high score flags a patient who may benefit from pharmacologic prophylaxis, and the final choice weighs active bleeding, low platelets, recent neurosurgery, and other contraindications. The score should also be repeated during the stay, because new events such as a central line, an infection, or prolonged bed rest can push it higher.
How is the 2005 Caprini model different from the 2013 version?
This calculator uses the 2005 model, which is the version most surgical calculators and studies rely on. The 2013 update keeps the same idea but adds risk factors such as smoking, insulin-dependent diabetes, chemotherapy, blood transfusion, and surgery lasting over two hours, and it sorts patients into four bands: low at 0 to 1, moderate at 2, high at 3 to 4, and very high at 5 or more. The two versions usually agree on who is high risk, but a borderline patient can land in a slightly different band.