Use this screening calculation or category only with a coagulation result measured by the stated method and compared with the matching laboratory control or reference interval.

Clotting time

A finite measured or assumed value from 30 through 600, expressed in s.

The implementation follows this calculation rule: Flag whether a clotting time between 30 and 600 seconds falls inside the normal range of 90 to 180 seconds inclusive.

Clotting time

The calculated clotting time in s.

Within normal range

Whether within normal range is true.

Bleeding and clotting tests do not measure the entire hemostatic system. Reagent sensitivity, specimen collection, anticoagulant therapy, platelet function, reference ranges, and clinical context can change interpretation; this tool is not a diagnosis or treatment recommendation. Its cutoffs are implementation rules and may not match every laboratory, species, population, or guideline.

Review the original coagulation panel and local reference range. Depending on the question, platelet count, prothrombin time, fibrinogen, thrombin time, mixing studies, or factor assays may provide the necessary complementary evidence.

• Bleeding Time Category

  Classify a bleeding time in minutes up to 30 as normal (<= 7), borderline (<= 15), or prolonged.

• APTT Ratio

  Compute the activated partial thromboplastin time ratio as the patient APTT divided by the control APTT.

• INR Ratio

  Compute the international normalized ratio as (patient PT / mean normal PT)^ISI. Use the International Sensitivity Index assigned to the specific thromboplastin reagent and instrument; the default of one is only appropriate when that is the calibrated ISI.