(77 days)
Pacific Hemostasis Thromboplastin D is an in vitro diagnostic reagent intended for use for the performance of Prothrombin Time (PT) testing and quantitative PT-based factor assays (for Factors II, V, VII and X).
Pacific Hemostasis Thromboplastin D is intended for use for performing the one-stage Prothrombin Time test (PT) and PT-based factor assays.
Pacific Hemostasis Thromboplastin D is a lyophilized extract of rabbit brain thromboplastin containing calcium, stabilizer and buffer.
Acceptance Criteria and Study for Pacific Hemostasis Thromboplastin D
This device is a Thromboplastin reagent intended for in vitro diagnostic use to perform Prothrombin Time (PT) testing and quantitative PT-based factor assays, as well as for monitoring oral anticoagulant (OAC) therapy. The study demonstrates substantial equivalence to a predicate device, Dade Thromboplastin C Plus.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Criteria | Reported Device Performance |
|---|---|---|
| Intended Use | Identical intended use as predicate device (Dade Thromboplastin C Plus): detect deficiencies in factors II, V, VII, and X (PT and PT-based factor assays); monitoring oral anticoagulant (OAC) therapy. | Met: Pacific Hemostasis Thromboplastin D has identical intended use, being formulated to detect deficiencies in factors II, V, VII and X (PT and PT-based factor assays) and for monitoring OAC therapy. |
| Technological Characteristics | Similar technological characteristics as predicate device. | Met: The device is described as a lyophilized extract of rabbit brain thromboplastin containing calcium, stabilizer, and buffer, similar to the predicate. |
| Correlation with Predicate Device (PT Testing) | High correlation coefficients (R) for PT testing of specimens from normal, abnormal, and OAC-treated patients. | Met: Correlation coefficients (R) ranging from 0.96-0.97 were obtained across two sites on multiple instruments. |
| Slope of Correlation (PT Testing) | Slopes of correlation consistent with clinical acceptance ranges for PT testing compared to predicate. | Met: Slopes ranging from 0.74-0.85 were observed. While this shows a potential bias in raw PT values, the subsequent INR conversion addresses this. |
| Bias Elimination (INR Conversion) | Elimination of bias when PT results are converted to INR, demonstrating accurate INR reporting. | Met: Bias was eliminated when results were converted to INR. |
| Correlation with Predicate Device (INR) | High correlation coefficients (R) for INR values compared to predicate device. | Met: Correlation coefficients (R) ranging from 0.95-0.97 were obtained for INR values. |
| Slope of Correlation (INR) | Slopes of correlation close to 1.0 for INR values compared to predicate device. | Met: Slope values between 0.98-1.04 were obtained for INR values, indicating excellent agreement. |
| Within-run Precision | Coefficient of Variation (CV) for within-run precision demonstrating high repeatability for the proposed device. | Met: CVs less than 3% were obtained for the proposed device. |
| Between-run Precision | Coefficient of Variation (CV) for between-run precision demonstrating high reproducibility for the proposed device. | Met: CVs less than 3% were obtained for the proposed device. |
| Precision compared to Predicate | Proposed device precision comparable to or better than predicate device. | Met: The predicate device (Dade Thromboplastin C Plus) showed CVs less than 4% for within-run and between-run precision, while the proposed device achieved CVs less than 3%, indicating superior or equivalent precision. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state a numerical sample size for the test set. It mentions "specimens from normal and abnormal patients, as well as samples from patients receiving OAC therapy."
The data provenance is not explicitly stated in terms of country of origin. However, the study was conducted at "two sites" using "multiple instruments," suggesting a multi-site correlation study. It is a retrospective clinical specimen study using collected patient samples.
3. Number of Experts and Qualifications for Ground Truth
Not applicable. This study focuses on the analytical performance and equivalence of a laboratory reagent rather than the diagnostic interpretation by experts. The "ground truth" here is the established measurement performance of the predicate device, not an expert's assessment of patient condition.
4. Adjudication Method
Not applicable, as this is an analytical performance study comparing a new reagent to a predicate, not a study involving expert review of diagnostic cases.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, an MRMC comparative effectiveness study was not done. This is not a diagnostic imaging or interpretation device that would involve human readers.
6. Standalone (Algorithm Only) Performance
Yes, the performance is essentially "standalone" as it refers to the analytical performance of the regent itself when used on laboratory instruments, without human interpretive input beyond following the testing protocol. The correlation and precision metrics directly assess the reagent's performance.
7. Type of Ground Truth Used
The ground truth for this study is implicitly established by the performance of the legally marketed predicate device (Dade Thromboplastin C Plus). The acceptance criteria are based on demonstrating analytical equivalence (correlation, bias, precision) to this established gold standard in the PT testing domain.
8. Sample Size for the Training Set
The document does not explicitly mention a "training set" as this is an analytical validation study of a reagent, not a machine learning model. The samples described in section 2 ("specimens from normal and abnormal patients, as well as samples from patients receiving OAC therapy") served as the study set for performance evaluation.
9. How the Ground Truth for the Training Set Was Established
Not applicable. As noted in section 8, there isn't a "training set" in the context of a machine learning model. The principle of ground truth in this study is the analytical results obtained when testing samples with the predicate device, which is a widely accepted and legally marketed reagent.
§ 864.7750 Prothrombin time test.
(a)
Identification. A prothrombin time test is a device used as a general screening procedure for the detection of possible clotting factor deficiencies in the extrinsic coagulation pathway, which involves the reaction between coagulation factors III and VII, and to monitor patients receiving coumarin therapy (the administration of one of the coumarin anticoagulants in the treatment of venous thrombosis or pulmonary embolism).(b)
Classification. Class II (performance standards).