Caprini Score VTE Calculator

The Caprini Risk Assessment Model (RAM) assigns point values to individual patient-level risk factors spanning demographic characteristics, comorbid conditions, surgical history, and laboratory findings. Each factor is weighted between 1 and 5 points based on its relative contribution to VTE risk. The cumulative score places the patient into one of four risk categories: Very Low (0 points), Low (1–2 points), Moderate (3–4 points), or High (≥ 5 points).

The scoring formula is a weighted summation: Caprini Score = Σ(w_i × x_i), where each risk factor x_i is present (1) or absent (0), multiplied by its assigned weight w_i. One-point factors include age 41–60, minor planned surgery, obesity (BMI > 25), swollen legs, varicose veins, oral contraceptive or hormone therapy use, sepsis, serious lung disease, acute MI, and inflammatory bowel disease. Two-point factors include major surgery lasting over 45 minutes, confined to bed (> 72 hours), immobilizing plaster cast, malignancy, and central venous access. Three-point factors include personal or family history of VTE and known thrombophilias. Five-point factors include elective major lower extremity arthroplasty, hip/pelvis/leg fracture, stroke, multiple trauma, and spinal cord injury.

Based on the final score, clinicians determine prophylaxis intensity. Very Low risk patients (score 0) typically require only early ambulation. Low risk patients (1–2) may receive mechanical prophylaxis such as compression stockings. Moderate risk patients (3–4) generally receive pharmacologic prophylaxis, while High risk patients (≥ 5) often require combined mechanical and pharmacologic prophylaxis with extended duration anticoagulation. This systematic approach reduces preventable hospital-acquired VTE events, which are among the most common causes of preventable in-hospital death.

The Caprini Score was developed primarily in surgical patients and its accuracy may be reduced in medical inpatients, critically ill patients, or outpatient settings where different VTE risk models (e.g., Padua Prediction Score, IMPROVE) may be more appropriate. The model does not directly account for every possible thrombophilia or drug interaction, and clinical judgment remains essential. Scores must be reassessed as the patient's condition evolves — a score calculated preoperatively may no longer reflect postoperative status after prolonged immobility or unexpected complications. The estimated VTE risk percentages are derived from population-level cohort data and represent probabilistic estimates rather than individual predictions. This calculator is intended as a clinical decision-support tool and should not replace the judgment of a qualified healthcare provider. Always confirm scoring criteria with the most current institutional protocols and published validation studies.