(589 days)
The STA- NeoPTimal kits provide thromboplastin reagents from rabbit brain extract, for the quantitative determination, in human citrated plasma (3.2% sodium citrate), of Prothrombin Time (PT) on STA-R family, STA Compact family and STA Satellite family instruments. STA- NeoPTimal is a coagulation screening test intended to be used by professional laboratory personnel for the evaluation of the extrinsic coagulation pathway and the monitoring of oral vitamin K antagonist therapy using the International Normalized Ratio (INR).
The in-vitro diagnostic STA® - NeoPTimal kits are available in two sizes and contains:
STA® - NeoPTimal 5: 6 x 5 ml vials of Reagent 1, 6 x 5 ml vials of Reagent 2
STA® - NeoPTimal 10: 12 x 10 ml vials of Reagent 1, 12 x 10 ml vials of Reagent 2
Reagent 1 is STA® - NeoPTimal, lyophilized thromboplastin prepared from rabbit brain extract. The STA® - NeoPTimal reagent contains a specific heparin inhibitor. Any prolongation of the prothrombin time is, therefore, related to a real deficiency of factor II, V, VII, X and/or fibrinogen.
Reagent 2 is a solvent containing calcium.
The test consists of the use of calcium thromboplastin to measure the clotting time of the patient's plasma and to compare it with that of a normal standard. The test measures, as a whole, the activities of the coagulation factor II (prothrombin), factor V (proaccelerin), factor VII (proconvertin), factor X (Stuart factor) and factor I (fibrinogen).
The PT value is expressed in seconds or INR. The result has to be interpreted according to the patient's clinical and biological states. The INR value corresponds to the ratio of the patient's PT to that of the standard PT raised to the ISI (International Sensitivity Index) power of the thromboplastin used:
INR = ( Patient's PT / Mean Normal PT ) * ISI
The ISI value of a given thromboplastin is determined by testing normal plasma and VKA (vitamin K antagonist)-treated patient plasma with that thromboplastin and with the International Reference preparation (RBT) for thromboplastin.
The provided text is a 510(k) summary for a medical device called STA-NeoPTimal, which is a Prothrombin Time (PT) test. The document primarily focuses on the device's performance characteristics, stability, and comparison to a predicate device. It does not describe a study involving human readers or AI assistance. Therefore, I cannot extract information related to MRMC studies, the number of experts for ground truth, or the sample size of a training set for an AI model from this document.
However, I can provide information based on the performance criteria and studies detailed in the document for the STA-NeoPTimal device itself.
Here's the information extracted and organized as requested, with details that are present in the document:
1. A table of acceptance criteria and the reported device performance
The document does not explicitly state "acceptance criteria" values in a table for each performance characteristic but rather describes that "acceptance criteria were met for all samples in the studies." The tables provided show the reported device performance.
Table of Performance Characteristics (Reported Device Performance)
| Performance Characteristic | Reported Device Performance |
|---|---|
| Precision/Reproducibility | |
| Single-site Precision | |
| STA R Max (seconds) | Total CV: 1.41% - 3.19% across 11 samples (mean PT: 13.861 - 70.665 seconds) |
| STA R Max (INR) | Total CV: 2.01% - 4.48% across 7 samples (mean INR: 1.0120 - 5.4507) |
| STA Compact Max (seconds) | Total CV: 1.80% - 5.09% across 11 samples (mean PT: 14.132 - 69.433 seconds) |
| STA Compact Max (INR) | Total CV: 2.56% - 6.87% across 7 samples (mean INR: 1.0321 - 5.3553) |
| STA Satellite (seconds) | Total CV: 2.00% - 3.82% across 11 samples (mean PT: 13.639 - 71.376 seconds) |
| STA Satellite (INR) | Total CV: 2.12% - 5.09% across 7 samples (mean INR: 1.0032 - 5.5795) |
| Multi-site Precision | |
| STA R Max (seconds) | Total CV: 2.86% - 3.63% across 11 samples (mean PT: 14.272 - 71.215 seconds) |
| STA R Max (INR) | Total CV: 3.22% - 4.26% across 7 samples (mean INR: 1.0434 - 5.4936) |
| STA Compact Max (seconds) | Total CV: 2.81% - 5.16% across 11 samples (mean PT: 14.291 - 70.780 seconds) |
| STA Compact Max (INR) | Total CV: 3.35% - 6.41% across 7 samples (mean INR: 1.0444 - 5.4617) |
| STA Satellite (seconds) | Total CV: 2.76% - 5.93% across 11 samples (mean PT: 13.957 - 74.733 seconds) |
| STA Satellite (INR) | Total CV: 3.02% - 7.19% across 7 samples (mean INR: 1.0275 - 5.8552) |
| Extrinsic Factor Sensitivity | Percentage of factor (STA NeoPTimal): Factor II: 46%, Factor V: 59%, Factor VII: 55%, Factor X: 65% |
| Interferences | No interference up to: Triglycerides (3270 mg/dL), Hemoglobin (4000 mg/dL), Conjugated Bilirubin (29 mg/dL), Unconjugated Bilirubin (20 mg/dL), UFH (1.0 IU/mL), LMWH (1.5 IU Anti-Xa/mL), Apixaban (13 ng/mL), Dabigatran (3 ng/mL), Edoxaban (6 ng/mL), Rivaroxaban (7 ng/mL). |
| Stability | |
| Sample Stability – Room Temp | Plasma stable for 24 hours at room temperature. |
| Sample Stability – Long-term Frozen | Plasma stable for 12 months at ≤ -70°C. |
| Shelf-life Stability | STA – NeoPTimal (5): 24 months at 2-8°C. |
| STA – NeoPTimal (10): 24 months at 2-8°C. | |
| In-Use Stability | STA-R family/STA Compact family: 48h on board for 5ml, 4 days on board for 10ml. |
| STA Satellite family: 48h on board for 5ml, 4 days on board for 10ml. | |
| 2-8°C: 8 days for both. | |
| Method Comparison | |
| Slope | 0.93 (95% CI: 0.92 to 0.95) |
| Intercept | 0.04 (95% CI: 0.02 to 0.06) |
| rPearson | 0.965 |
| Bias at 2.5 INR | -5.3% (95% CI: -6.2% to -4.3%) |
| Bias at 3.5 INR | -5.7% (95% CI: -6.9% to -4.6%) |
| Reference Interval | 11.8 to 14.9 seconds, and 0.89 to 1.11 INR for adults. |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Precision/Reproducibility (Single-site): Each sample type (11 samples for seconds, 7 for INR) was tested with N=240 replicates (2 replicates/day over 20 days) on each of three instruments (STA R Max, STA Compact Max, STA Satellite). Data provenance is "one external site" for single-site testing.
- Precision/Reproducibility (Multi-site): Each sample type (11 samples for seconds, 7 for INR) was tested with N=270 replicates (2 runs/day over 5 days at 3 sites per analyzer). Data provenance is "three external sites" per analyzer.
- Extrinsic Factor Sensitivity: Not explicitly stated, but implies the use of contrived samples with known factor levels.
- Interferences: Four samples were used: 1 normal, 2 VKA patient samples (INR 2.0-3.0 and 3.1-4.5), and 1 Deficient V patient sample.
- Sample Stability (Room Temperature): Four normal samples and eight VKA samples (INR 1.5 to 5.5).
- Sample Stability (Long-term Frozen): 53 samples stored at ≤ -70°C (Normal and VKA patient samples with INR between 1.5 and 5.0).
- Shelf-life Stability: 10 samples (Normal, VKA patient samples with INR 2-4.5, Deficient V, Quality controls).
- In-Use Stability: Six samples (Normal, VKA 2-3, VKA 3-4.5, Deficient V, Two controls).
- Method Comparison: Not explicitly stated, but it was an "external method comparison study" involving "four sites" comparing STA NeoPTimal with Thromborel S.
- Reference Interval: 137 patients. Data provenance is "across three external sites."
The document does not explicitly state the country of origin for the data or whether the studies were retrospective or prospective, but as performance validation studies for a device, they are typically prospective.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
This is not applicable as the device is an in-vitro diagnostic test for Prothrombin Time, and the "ground truth" (or reference values) is established through laboratory methods and reference standards, not expert interpretation of qualitative data like images.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable for this type of in-vitro diagnostic device performance study.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
Not applicable. The document describes a laboratory diagnostic device, not an AI-assisted diagnostic tool that would involve human readers interpreting results.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
The device is a standalone in-vitro diagnostic reagent kit used on automated instruments (STA-R family, STA Compact family, STA Satellite family). Its performance is evaluated directly (algorithm-like in terms of automated measurement) without direct human interpretation in the loop of the measurement itself, though human professionals use the results.
7. The type of ground truth used (expert concensus, pathology, outcomes data, etc)
The "ground truth" for this in-vitro diagnostic device is established by:
- Reference Intervals: Determined using a population of 137 patients according to CLSI guideline EP28-A3c.
- Comparison to Predicate Device: Performance is compared to an existing, legally marketed predicate device (Thromborel® S) using a method comparison study.
- Known Concentrations/Levels: For intrinsic validity testing like Extrinsic Factor Sensitivity and Interference studies, controlled samples with known concentrations of factors or interfering substances are used.
- Standardized Prothrombin Time Measurement: The core measurement (PT) itself is a standardized laboratory test.
8. The sample size for the training set
Not applicable. This document describes a new in-vitro diagnostic reagent, not a machine learning model. There is no concept of a "training set" in this context.
9. How the ground truth for the training set was established
Not applicable.
§ 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).