Table I.
Point values for predictors of venous thromboembolism (VTE) from the National Inpatient Sample (NIS) VTE calculator of risk13
| Predictor | Point value* | Incidence in study population (%) |
|---|---|---|
| Anaemia | 16 | 17.9 |
| Congestive heart failure | 22 | 1.6 |
| Coagulation deficiency | 39 | 3.5 |
| Lymphoma | 30 | 0.3 |
| Fluid and electrolyte disorders | 45 | 8.1 |
| Metastatic cancer | 87 | 0.4 |
| Peripheral vascular disease | 10 | 3.7 |
| Nonmetastatic solid tumors | 16 | 3.5 |
| Weight loss | 46 | 1.3 |
| Chronic pulmonary heart disease | 61 | 0.7 |
| Blood transfusion | 32 | 0.6 |
| History of VTE | 30 | 2.6 |
| Myeloproliferative disorders | 38 | 0.5 |
| Hypercoagulable state | 100 | 0.2 |
| Myocardial infarction | 13 | 4.5 |
| Varicose veins | 28 | 4.5 |
| Fracture | 43 | 1.8 |
| Inflammatory bowel disease | 17 | 0.5 |
| Sepsis | 72 | 0.1 |
| Periprosthetic joint infection | 27 | 0.3 |
| Atrial fibrillation | 30 | 5.1 |
| Stroke | 78 | 1.0 |
| Apnea | 9 | 10.0 |
| Bilateral joints† | 21 | 19.4 |
| Not primary THA | 43 | 100.0 |
| Age (yrs)‡ | 0.267 × yrs over 40 | N/A |
*Point values of predictors are added to calculate an NIS VTE score for each patient †Bilateral joints omitted from NIS VTE score calculation in this study dz, disease; VTE, venous thromboembolism; ‡For this portion of the formula used to calculate a patient’s NIS Risk Score, every year of the patient’s age over 40 is multiplied by 0.267. For a 60-year-old patient, for example, this would be 0.267 × (60 - 40) = 5.34 THA, total hip arthroplasty; N/A, not applicable