How It Works
Study Design
The study requires PT measurements from healthy subjects — individuals with no known coagulation disorders, not taking anticoagulant medications, and collected using the same reagent lot and instrument that will be used for patient testing. All samples should be tested under routine conditions that reflect the laboratory's standard operating procedures.
| Requirement | Specification |
|---|---|
| Minimum samples | 20 normal subjects |
| Recommended samples | ≥60 subjects (WHO); ≥120 subjects for reference interval establishment |
| Maximum samples | 500 per study |
| Subject criteria | No known coagulation disorders, no anticoagulant therapy |
| Specimen type | Fresh citrated plasma (3.2% sodium citrate) |
| Test conditions | Same reagent lot, instrument, and operator conditions as routine patient testing |