(124 days)
The STA® - Liatest® D-Di kit is an immuno-turbidimetric assay for the quantitative determination of D-dimer in venous plasma (in 3.2% sodium citrate) for use on STA-R®, STA Compact® and STA Satellite® analyzers by professional laboratory personnel. The STA® - Liates® D-Di is intended for use in conjunction with a clinical pretest probability (PTP) assessment model to exclude pulmonary embolism (PE) and as an aid in the diagnosis of deep venous thrombosis (DVT) in outpatients suspected of PE or DVT.
STA® - Liatest® D-Di kit contains: 6 x 5-ml vials of ready-for-use Tris buffer and 6 x 6-ml vials of a suspension of microlatex particles coated with two different mouse monoclonal anti-human D-dimer antibodies (8D2 and 2.1.16) stabilized with bovine albumin.
The test principle is based on the change in turbidity of a microparticle suspension that is measured by photometry. A suspension of latex microparticles, coated by covalent bonding with monoclonal antibodies specific for D-dimer is mixed with the test plasma for which the D-dimer level is to be assayed. An antigen-antibody reaction takes place, leading to an agglutination of the latex microparticles which causes an increase in turbidity of the reaction medium. This increase in turbidity is reflected by an increase in absorbance, the latter being measured photometrically. The increase in absorbance is a function of the D-dimer level present in the test sample.
Here's a breakdown of the acceptance criteria and the study details for the STA® - Liatest® D-Di device, based on the provided document:
Acceptance Criteria and Reported Device Performance
The acceptance criteria for the STA® - Liatest® D-Di device are implicitly tied to its ability to
safely rule out Pulmonary Embolism (PE) in patients with low or moderate pretest probability (PTP).
The key performance metric for exclusion of PE is the Negative Predictive Value (NPV).
| Performance Metric | Acceptance Criteria (Implied by Study) | Reported Device Performance (Overall Study Population) |
|---|---|---|
| Sensitivity for PE | High sensitivity to minimize false negatives | 97.0 % (95% CI: 91.6 % - 99.4 %) |
| NPV for PE Exclusion | High NPV to safely rule out PE | 99.7 % (95% CI: 99.2 % - 100.0 %) |
| Specificity for PE | (No explicit threshold, but reported for completeness) | 75.5 % (95% CI: 72.8 % - 78.1 %) |
| PPV for PE | (No explicit threshold, but reported for completeness) | 25.5 % (95% CI: 23.5 % - 27.7 %) |
| Clinical Cut-off | D-dimer level < 0.50 µg/ml (FEU) for PE exclusion | 0.50 µg/ml (FEU) |
Study Details
-
Sample Size used for the test set and the data provenance:
- Total Test Set Sample Size: 1130 samples of patients with a low or moderate PTP.
- Prospective Study Population: 1060 samples.
- US Banked Samples (retrospective): 70 samples.
- Data Provenance: The study involved multiple centers across the United States, Europe, and Canada for the prospective data. The banked samples were from the US. The overall study is a mix of prospective and retrospective data.
- Total Test Set Sample Size: 1130 samples of patients with a low or moderate PTP.
-
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
The document does not specify the number or qualifications of experts used to establish the ground truth. The ground truth was established through a combination of imaging procedures for positive PE cases and a 3-month follow-up for negative PE cases. -
Adjudication method for the test set:
The document does not explicitly describe a specific adjudication method for the test set results. Diagnosis of PE was based on imaging or clinical follow-up. For patients with suspected PE, those with positive D-dimer results were considered for an imaging procedure. Patients with negative D-dimer results were considered not to have PE and were assigned to a three-month follow-up. This implies a diagnostic pathway rather than a direct adjudication process by a panel of experts on each case. -
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:
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This device is an in-vitro diagnostic assay (D-dimer test) and not an AI-assisted diagnostic imaging device that would typically involve human readers. Therefore, the concept of human readers improving with or without AI assistance is not applicable here. -
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
Yes, a standalone performance study was done for the STA® - Liatest® D-Di device. The reported sensitivity, specificity, NPV, and PPV are for the device's performance alone in determining D-dimer levels and, in conjunction with PTP, for PE exclusion. While the device is "intended for use in conjunction with a clinical pretest probability (PTP) assessment model," the performance metrics presented specifically reflect the diagnostic accuracy of the D-dimer assay within that pathway. -
The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
The ground truth was established through a combination of imaging procedures (for positive PE cases) and outcomes data (3-month follow-up for negative PE cases). -
The sample size for the training set:
The document does not specify a separate training set sample size. The study focuses on demonstrating the performance of the device in a clinical setting based on a defined test set. For an in-vitro diagnostic like this, the "training" (e.g., assay optimization, establishing parameters) is typically internal to the manufacturer's development process and not part of the clinical performance study reported for regulatory submission in the same way an AI model's training set would be. -
How the ground truth for the training set was established:
As no separate "training set" is described in the context of this regulatory submission, how its ground truth was established is not provided. The ground truth for the test set was established as described in point 6.
{0}------------------------------------------------
Image /page/0/Picture/1 description: The image is a black and white logo for the U.S. Department of Health & Human Services. The logo features a stylized caduceus symbol, which is a staff with two snakes coiled around it. To the left of the symbol, the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged in a circular fashion.
Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002
September 3, 2014
Diagnostica Stago c/o Mr. Carlo d'Alessandro, Director, IVD Quality and Regulatory Donawa Lifescience Consulting Srl Piazza Albania, 10 Rome, Italy 00153
Re: K141144
Trade/Device Name: STA® - Liatest® D-Di Regulation Number: 21 CFR 864.7320 Regulation Name: Fibrinogen/fibrin degradation products assay Regulatory Class: Class II Product Code: DAP Dated: August 1, 2014 Received: August 4, 2014
Dear Mr. d'Alessandro:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you; however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21
{1}------------------------------------------------
CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please contact the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to
http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.
Sincerely yours.
Maria M. Chan -S
Maria M. Chan, Ph.D. Director Division of Immunology and Hematology Devices Office of In Vitro Diagnostics and Radiological Health (OIR) Center for Devices and Radiological Health
Enclosure
{2}------------------------------------------------
Indications for Use
510(k) Number (if known) K141144
Device Name STA® - Liatest® D-Di
The STA® - Liatest® D-Di kit is an immuno-turbidimetric assay for the quantitative determination of D-dimer in venous plasma (in 3.2% sodium citrate) for use on STA-R®, STA Compact® and STA Satellite® analyzers by professional laboratory personnel. The STA® - Liates® D-Di is intended for use in conjunction with a clinical pretest probability (PTP) assessment model to exclude pulmonary embolism (PE) and as an aid in the diagnosis of deep venous thrombosis (DVT) in outpatients suspected of PE or DVT.
Type of Use (Select one or both, as applicable)
ك Prescription Use (Part 21 CFR 801 Subpart D)
_ Over-The-Counter Use (21 CFR 801 Subpart C)
PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON A SEPARATE PAGE IF NEEDED.
FOR FDA USE ONLY
Concurrence of Center for Devices and Radiological Health (CDRH) (Signature)
Maria M. Chan -S
This section applies only to requirements of the Paperwork Reduction Act of 1995.
DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW!
The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:
Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff@fda.hhs.gov
"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."
Form Approved: OMB No. 0910-0120 Expiration Date: January 31, 2017 See PRA Statement below.
{3}------------------------------------------------
Image /page/3/Picture/0 description: The image shows the logo for Stago. The logo consists of the word "Stago" in red, with a stylized graphic above it. The graphic appears to be two curved shapes, one red and one brown, arranged in a circular fashion.
510(k) Summary
| Submitter Information: | Diagnostica Stago125 avenue Louis Roche92230 Gennevilliers, FranceFranceContact name: Mr. Arnaud CollinTel: +33 1 46 85 48 80 (main)+33 1 30 72 36 09Fax: +33 1 41 47 57 50 |
|---|---|
| Date of Submission: | 30 April 2014 |
| Application Correspondentand Contact Person: | Mr. Carlo d'Alessandro,Director, IVD Quality and RegulatoryDonawa Lifescience Consulting SrlPiazza Albania, 10 - 00153 Rome, ItalyTel: +39 06 578 2665Fax: +39 06 574 3786cdalessandro@donawa.com |
| Device Trade Name: | STA® - Liatest® D-Di |
| Regulatory Information: | |
| Classification Name: | Fibrinogen and fibrin split products, antigen, antiserum, control |
| Regulatory Class: | Class II |
| Panel: | Hematology |
| Product Code: | DAP |
| Regulation Number: | 864.7320 |
| Predicate Devices: | STA® - Liatest® D-Di (K964728)VIDAS® D-Dimer Exclusion™ (K040882) |
Device Intended Use:
✔ New Device Intended Use
The STA® - Liatest® D-Di kit is an immuno-turbidimetric assay for the quantitative determination of D-dimer in venous plasma (in 3.2% sodium citrate) for use on STA-R®, STA Compact® and STA Satellite® analyzers by professional laboratory personnel. The STA® - Liatest® D-Di is intended for use in conjunction with a clinical pretest probability (PTP) assessment model to exclude pulmonary embolism (PE) and as an aid in the diagnosis of deep venous thrombosis (DVT) in outpatients suspected of PE or DVT.
{4}------------------------------------------------
Image /page/4/Picture/0 description: The image shows the logo for Stago. The logo features the word "Stago" in a red, serif font. Above the word is an abstract graphic that resembles a stylized leaf or flame in two colors: red and brown. The red portion is on top, and the brown portion is below.
✓ Previous Device Intended Use
The STA® - Liatest® D-Di kit is intended for use with STA-R®, STA Compact® and STA Satellite® analyzers for the quantitative determination of D-dimer in plasma by the immunoturbidimetric method. The STA® - Liatest® D-Di assay can be used to aid in the diagnosis of deep venous thrombosis and pulmonary embolism disease.
Device description:
STA® - Liatest® D-Di kit contains: 6 x 5-ml vials of ready-for-use Tris buffer and 6 x 6-ml vials of a suspension of microlatex particles coated with two different mouse monoclonal anti-human D-dimer antibodies (8D2 and 2.1.16) stabilized with bovine albumin.
The test principle is based on the change in turbidity of a microparticle suspension that is measured by photometry. A suspension of latex microparticles, coated by covalent bonding with monoclonal antibodies specific for D-dimer is mixed with the test plasma for which the D-dimer level is to be assayed. An antigen-antibody reaction takes place, leading to an agglutination of the latex microparticles which causes an increase in turbidity of the reaction medium. This increase in turbidity is reflected by an increase in absorbance, the latter being measured photometrically. The increase in absorbance is a function of the D-dimer level present in the test sample.
Statement of technological characteristics of the device compared to predicate devices:
The STA® - Liatest® D-Di kit is equivalent to the currently marketed STA® - Liatest® D-Di (K964728). The only change applied is the expanded intended use. The STA® - Liatest® D-Di kit and the Vidas® D-Dimer Exclusion™ (K040882) have different assay method and test principle. However, both kits are equivalent considering their intended use for excluding PE.
| Device | Predicate Device | |
|---|---|---|
| Attributes orcharacteristics | Diagnostica Stago,STA® - Liatest® D-Di | Diagnostica Stago,STA® - Liatest® D-DiK964728 |
| Analyte(s)measured | D-dimer | D-dimer |
| Assay Method | Immuno-turbidimetric method | Immuno-turbidimetric method |
| Test Principle | Immuno-turbidimetric method basedon the measurement of lightabsorbance (at 540 nm) produced bya suspension of microlatex particlescoated with specific mouse anti-human D-dimer monoclonalantibodies. | Immuno-turbidimetric method basedon the measurement of lightabsorbance (at 540 nm) produced bya suspension of microlatex particlescoated with specific mouse anti-human D-dimer monoclonalantibodies |
| Analyzers | IVD analyzers of the STA® line:STA-R® (original 510(k) number:K983460), STA Compact® (original510(k) number: K961579) and STASatellite® (original 510(k) number:K082248). | IVD analyzers of the STA® line:STA-R® (original 510(k) number:K983460), STA Compact® (original510(k) number: K961579) and STASatellite® (original 510(k) number:K082248). |
- Similarities Chart with STA® Liatest® D-Di (K964728) .
{5}------------------------------------------------
Image /page/5/Picture/0 description: The image contains the logo for Stago. The logo features the word "Stago" in a red, serif font. Above the word, there is an abstract graphic consisting of two curved shapes. One shape is red, and the other is brown. The shapes are arranged in a way that suggests movement or flow.
| Attributes orcharacteristics | DeviceDiagnostica Stago,STA® - Liatest® D-Di | Predicate DeviceDiagnostica Stago,STA® - Liatest® D-DiK964728 |
|---|---|---|
| Anatomical Sites | Not applicable.No direct patient contact. | Not applicable.No direct patient contact. |
| Where Used:Hospital, home,ambulance, etc. | Hospital Laboratory or other HealthCare Laboratory. | Hospital Laboratory or other HealthCare Laboratory. |
| Sterility | No sterility requirements.No direct patient contact. | No sterility requirements.No direct patient contact. |
| Biocompatibility | No biocompatibility requirements.No direct patient contact. | No biocompatibility requirements.No direct patient contact. |
| Chemical Safety | No issues regarding chemical safetydue to no direct patient contact. | No issues regarding chemical safetydue to no direct patient contact. |
Differences Chart with STA® - Liatest® D-Di (K964728) •
| Attributes orcharacteristics | Device | Predicate Device |
|---|---|---|
| Indications forUse | Diagnostica Stago,STA® - Liatest® D-Di | Diagnostica Stago,STA® - Liatest® D-DiK964728 |
| Quantitative determination of D-dimer in venous plasma (in 3.2%sodium citrate). The assay is intendedfor use in conjunction with a clinicalpretest probability (PTP) assessmentmodel to exclude pulmonaryembolism (PE) and as an aid in thediagnosis of deep venous thrombosis(DVT) in outpatients suspected of PEor DVT. | Quantitative determination of D-dimer in plasma. The assay can beused to aid in the diagnosis of deepvenous thrombosis and pulmonaryembolism disease. |
- Similarities Chart with VIDAS® D-Dimer Exclusion™ (K040882) .
| Attributes orcharacteristics | Device | Predicate Device |
|---|---|---|
| Diagnostica Stago,STA® - Liatest® D-Di | bioMérieux,VIDAS® D-Dimer Exclusion™K040882 | |
| Indications forUse | Quantitative determination of D-dimer in venous plasma (in 3.2%sodium citrate). The assay is intendedfor use in conjunction with a clinicalpretest probability (PTP) assessmentmodel to exclude pulmonaryembolism (PE) and as an aid in thediagnosis of deep venous thrombosis(DVT) in outpatients suspected of PEor DVT. | Automated quantitative test for useon the VIDAS instruments for theimmunoenzymatic determination offibrin degradation products (FbDP)in human plasma (sodium citrate)using ELFA technique (EnzymeLinked Fluorescent Assay). Theassay is indicated for use inconjunction with a clinical pretestprobability assessment model toexclude deep vein thrombosis (DVT)and pulmonary embolism (PE)disease in outpatients suspected ofPE or DVT. |
{6}------------------------------------------------
Image /page/6/Picture/0 description: The image shows the logo for Stago. The logo consists of the word "Stago" in red, with a stylized graphic above it. The graphic appears to be a circular shape with two sections, one red and one brown, that are partially overlapping. The logo is simple and modern.
| Device | Predicate Device | |
|---|---|---|
| Attributes orcharacteristics | Diagnostica Stago,STA® - Liatest® D-Di | bioMérieux,VIDAS® D-Dimer Exclusion™K040882 |
| Analyte(s)measured | D-dimer | D-dimer |
| Cut-off | 0.5 µg/mL | 500 ng/mL (same) |
| Clinicalperformances | For exclusion of PE on low andmoderate PTP population (n = 1130):Sensitivity = 97.0% (95% CI: 91.6% – 99.4%)NPV = 99.7% (95% CI: 99.2% – 100.0%) | For exclusion of PE on low andmoderate PTP population (n = 891):Sensitivity: 100.0 % (95% CI: 97.7% – 100.0 %)NPV: 100.0 % (95% CI: 98.7 % – 100.0 %) |
| Anatomical Sites | Not applicable.No direct patient contact. | Not applicable.No direct patient contact. |
| Where Used:Hospital, home,ambulance, etc. | Hospital Laboratory or other HealthCare Laboratory. | Hospital Laboratory or other HealthCare Laboratory. |
| Sterility | No sterility requirements.No direct patient contact. | No sterility requirements.No direct patient contact. |
| Biocompatibility | No biocompatibility requirements.No direct patient contact. | No biocompatibility requirements.No direct patient contact. |
| Chemical Safety | No issues regarding chemical safetydue to no direct patient contact. | No issues regarding chemical safetydue to no direct patient contact. |
Differences Chart with VIDAS® D-Dimer Exclusion™ (K040882) •
| Device | Predicate Device | ||
|---|---|---|---|
| Attributes orcharacteristics | Diagnostica Stago,STA® - Liatest® D-Di | bioMérieux,VIDAS® D-Dimer Exclusion™ | |
| K040882 | |||
| Assay Method | Immuno-turbidimetric method | ELFA technique (Enzyme Linked | |
| Fluorescent Assay) | |||
| Test Principle | Immuno-turbidimetric method basedon the measurement of lightabsorbance (at 540 nm) produced bya suspension of microlatex particlescoated with specific mouse anti-D-dimerhumanmonoclonalantibodies. | The assay combines a two-stepenzymeimmunoassaysandwichmethod with a final fluorescentdetection step (ELFA). | |
| Analyzers | IVD analyzers of the STA® line. | VIDAS instruments |
{7}------------------------------------------------
Image /page/7/Picture/0 description: The image shows the logo for Stago. The logo consists of the word "Stago" in a red, serif font. Above the word is an abstract graphic of two curved shapes, one red and one brown, that appear to be overlapping or interacting with each other. The overall design is simple and modern.
Clinical Performance Data:
A clinical multi-center study (9 sites over the United States, Europe and Canada), conducted according to CLSI H59-A, was performed to demonstrate the ability of STA® - Liatest® D-Di to safely rule-out PE by using samples of outpatients prospectively and consecutively enrolled in emergency departments. All patients suspected of having a PE were evaluated with the Wells' model to assess their pre-test probability (PTP) score (Low, Moderate or High):
- Patients with low or moderate PTP were considered for D-dimer testing, those with positive Ddimer result were considered for an imaging procedure, and those with negative D-dimer result were considered as not having PE and assigned to three month follow up.
- Patients with high PTP were considered for an imaging procedure and not included in the study population.
For analysis the population of interest was limited to patients with a PTP results low or moderate.
The prospective study population was enriched with US banked frozen samples collected during a similar clinical study (1).
Results:
1130 samples of patients with a low or moderate PTP were used for the final analysis. 1060 were from the prospective study population and 70 were from the US banked frozen samples.
The overall prevalence of PE (low and moderate PTP patients with positive imaging) in the prospective study population was 8.4 % with 2.7 % in the US population and 11.4 % in the European/Canadian ("out of US") population.
Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) with upper and lower limit of 95 % confidence intervals (CI) were calculated in the overall study population, and separately for the US population and the "out of US" population with the STA® -Liatest® D-Di clinical cut-off of 0.50 µg/ml (FEU) in the (low + moderate) PTP group of patients.
Results obtained for each study population are detailed below:
Table 1 Results obtained on the overall study population
| Overall | Reference (imaging or 3-month follow-up) | |||
|---|---|---|---|---|
| Positive | Negative | Total | ||
| D-dimer | Positive | 98 | 252 | 350 |
| Negative | 3 | 777 | 780 | |
| Total | 101 | 1029 | 1130 | |
| Sensitivity (95 % CI) = | 97.0 % (91.6 % - 99.4 %) | |||
| Specificity (95 % CI) = | 75.5 % (72.8 % - 78.1 %) | |||
| NPV (95 % CI) = | 99.7 % (99.2 % - 100.0 %) | |||
| PPV (95 % CI) = | 25.5 % (23.5 % - 27.7 %) |
{8}------------------------------------------------
Image /page/8/Picture/0 description: The image shows the logo for Stago. The logo consists of the word "Stago" in a red, serif font. Above the word is an abstract graphic of a red and brown shape that resembles a stylized flower or leaf. The red portion is on top, and the brown portion is below.
| US | Reference (imaging or 3-month follow-up) | ||
|---|---|---|---|
| Positive | Negative | Total | |
| D-dimer | |||
| Positive | 8 | 78 | 86 |
| Negative | 1 | 271 | 272 |
| Total | 9 | 349 | 358 |
| Sensitivity (95 % CI) = 88.9 % (51.8 % - 99.7 %) | |||
| Specificity (95 % CI) = 77.7 % (72.9 % - 81.9 %) | |||
| NPV (95 % CI) = 99.6 % (98.0 % - 100.0 %) | |||
| PPV (95 % CI) = 9.3 % (4.1 % - 17.5 %) |
Table 2 Results obtained on the US prospective study population
Table 3 Results obtained on the "out of US" prospective study population
| Reference (imaging or 3-month follow-up) | ||||
|---|---|---|---|---|
| Out of US | D-dimer | Positive | Negative | Total |
| Positive | 74 | 145 | 219 | |
| Negative | 1 | 482 | 483 | |
| Total | 75 | 627 | 702 | |
| Sensitivity (95 % CI) = | 98.7 % (92.8 % - 100.0 %) | |||
| Specificity (95 % CI) = | 76.9 % (73.4 % - 80.1 %) |
| Specificity (95 % CI) = | 76.9 % (73.4 % - 80.1 %) | |
|---|---|---|
| NPV (95 % CI) = | 99.8 % (98.9 % - 100.0 %) | |
| PPV (95 % CI) = | 33.8 % (27.6 % - 40.5 %) |
Additionally, sensitivity and specificity with upper and lower limit of 95 % confidence intervals (CI) were calculated in the US banked samples with the STA® - Liatest® D-Di clinical cut-off of 0.50 ug/ml (FEU). Results obtained are detailed below.
Table 4 Results obtained on the US banked samples
| Banked samples | Reference (imaging or 3-month follow-up) | |||
|---|---|---|---|---|
| Positive | Negative | Total | ||
| D-dimer | Positive | 16 | 29 | 45 |
| Negative | 1 | 24 | 25 | |
| Total | 17 | 53 | 70 | |
| Sensitivity (95 % CI) = 94.1 % (71.3 % - 99.9 %) | ||||
| Specificity (95 % CI) = 45.3 % (31.6 % - 59.6 %) |
This study demonstrates that the STA® - Liatest® D-Di is effective in excluding pulmonary embolism (PE) in patient with a low or moderate PTP and a D-dimer level < 0.50 µg/ml (FEU) with a negative predictive value of 99.7 % (confidence interval 95 %: 99.2 % to 100.0 %), according to CLSI H59-A requirements.
Reference :
-
- KLINE J.A., HOGG M.M., COURTNEY D.M., MILLER C.D., JONES A.E., SMITHLINE H.A .: "D-dimer Threshold Increase with Pretest Probability Unlikely for Pulmonary Embolism to Decrease Unnecessary Computerized Tomographic Pulmonary Angiography". Thromb. Haemostasis, 10, 572-581, 2012.
§ 864.7320 Fibrinogen/fibrin degradation products assay.
(a)
Identification. A fibrinogen/fibrin degradation products assay is a device used to detect and measure fibrinogen degradation products and fibrin degradation products (protein fragments produced by the enzymatic action of plasmin on fibrinogen and fibrin) as an aid in detecting the presence and degree of intravascular coagulation and fibrinolysis (the dissolution of the fibrin in a blood clot) and in monitoring therapy for disseminated intravascular coagulation (nonlocalized clotting in the blood vessels).(b)
Classification. Class II (performance standards).