Predicate Devices

Reference Devices

Not Found

AI/ML (Artificial Intelligence / Machine Learning)

No
The device is a laboratory assay kit that uses an immuno-turbidimetric method to measure D-dimer levels. The principle is based on a chemical reaction and photometric measurement, not AI/ML analysis of data. The summary explicitly states "Mentions AI, DNN, or ML: Not Found".

Therapeutic

No
The device is an in-vitro diagnostic assay used to determine D-dimer levels, which aids in diagnosing conditions like pulmonary embolism and deep venous thrombosis. It does not provide any therapy or treatment.

Diagnostic

Yes

The "Intended Use / Indications for Use" section explicitly states that the device 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)". This directly indicates its role in diagnosis.

SaMD (Software as a Medical Device)

No

The device description clearly states it is a "kit" containing vials of buffer and microlatex particles, which are physical components, not software. The test principle is based on a chemical reaction and photometric measurement, indicating a hardware-dependent process.

IVD (In Vitro Diagnostic)

Yes, this device is an IVD (In Vitro Diagnostic).

Here's why:

Intended Use: The intended use explicitly states it's an "immuno-turbidimetric assay for the quantitative determination of D-dimer in venous plasma... for use on STA-R®, STA Compact® and STA Satellite® analyzers by professional laboratory personnel." This describes a test performed on a biological sample (plasma) outside of the body to provide information about a patient's health status.
Device Description: The description details the components of a kit used for a laboratory test (reagents, microparticles, antibodies) and the principle of the test (antigen-antibody reaction leading to turbidity change measured by photometry). This is characteristic of an in vitro diagnostic device.
Anatomical Site: The "Not applicable. No direct patient contact" further supports that the test is performed on a sample taken from the patient, not directly on the patient's body.
Intended User / Care Setting: The intended users are "professional laboratory personnel" in a "Hospital Laboratory or other Health Care Laboratory," which are typical settings for performing in vitro diagnostic tests.
Performance Studies: The description of clinical studies involving testing patient samples and reporting performance metrics like sensitivity, specificity, and NPV are standard for demonstrating the clinical utility of an IVD.

All of these elements align with the definition and characteristics of an In Vitro Diagnostic device.

PCCP (Predetermined Change Control Plan) Authorized

N/A

Overview

Intended Use / Indications for 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.

Product codes (comma separated list FDA assigned to the subject device)

DAP

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.

Mentions image processing

Not Found

Mentions AI, DNN, or ML

Not Found

Input Imaging Modality

Not Found

Anatomical Site

Not applicable. No direct patient contact.

Indicated Patient Age Range

Not Found

Intended User / Care Setting

professional laboratory personnel.
Hospital Laboratory or other Health Care Laboratory.

Description of the training set, sample size, data source, and annotation protocol

Not Found

Description of the test set, sample size, data source, and annotation protocol

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).

Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)

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.
Sample Size: 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.
Overall study population: Sensitivity = 97.0 % (95% CI: 91.6 % - 99.4 %), Specificity = 75.5 % (72.8 % - 78.1 %), NPV = 99.7 % (99.2 % - 100.0 %), PPV = 25.5 % (23.5 % - 27.7 %)
US prospective study population: Sensitivity = 88.9 % (51.8 % - 99.7 %), Specificity = 77.7 % (72.9 % - 81.9 %), NPV = 99.6 % (98.0 % - 100.0 %), PPV = 9.3 % (4.1 % - 17.5 %)
"out of US" prospective study population: Sensitivity = 98.7 % (92.8 % - 100.0 %), Specificity = 76.9 % (73.4 % - 80.1 %), NPV = 99.8 % (98.9 % - 100.0 %), PPV = 33.8 % (27.6 % - 40.5 %)
US banked samples: Sensitivity (95 % CI) = 94.1 % (71.3 % - 99.9 %), Specificity (95 % CI) = 45.3 % (31.6 % - 59.6 %)
Key results: 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

Regulation Number and Section

§ 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).

Summary

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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.

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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 Stago
125 avenue Louis Roche
92230 Gennevilliers, France
France
Contact name: Mr. Arnaud Collin
Tel: +33 1 46 85 48 80 (main)
+33 1 30 72 36 09
Fax: +33 1 41 47 57 50 |
|--------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Date of Submission: | 30 April 2014 |
| Application Correspondent
and Contact Person: | Mr. Carlo d'Alessandro,
Director, IVD Quality and Regulatory
Donawa Lifescience Consulting Srl
Piazza Albania, 10 - 00153 Rome, Italy
Tel: +39 06 578 2665
Fax: +39 06 574 3786
cdalessandro@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 or
characteristics	Diagnostica Stago,
STA® - Liatest® D-Di	Diagnostica Stago,
STA® - Liatest® D-Di
K964728
Analyte(s)
measured	D-dimer	D-dimer
Assay Method	Immuno-turbidimetric method	Immuno-turbidimetric method
Test Principle	Immuno-turbidimetric method based
on the measurement of light
absorbance (at 540 nm) produced by
a suspension of microlatex particles
coated with specific mouse anti-
human D-dimer monoclonal
antibodies.	Immuno-turbidimetric method based
on the measurement of light
absorbance (at 540 nm) produced by
a suspension of microlatex particles
coated with specific mouse anti-
human D-dimer monoclonal
antibodies
Analyzers	IVD analyzers of the STA® line:
STA-R® (original 510(k) number:
K983460), STA Compact® (original
510(k) number: K961579) and STA
Satellite® (original 510(k) number:
K082248).	IVD analyzers of the STA® line:
STA-R® (original 510(k) number:
K983460), STA Compact® (original
510(k) number: K961579) and STA
Satellite® (original 510(k) number:
K082248).

Similarities Chart with STA® Liatest® D-Di (K964728) .

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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 or
characteristics | Device
Diagnostica Stago,
STA® - Liatest® D-Di | Predicate Device
Diagnostica Stago,
STA® - Liatest® D-Di
K964728 |
|---------------------------------------------------|--------------------------------------------------------------------------|---------------------------------------------------------------------------|
| Anatomical Sites | Not applicable.
No direct patient contact. | Not applicable.
No direct patient contact. |
| Where Used:
Hospital, home,
ambulance, etc. | Hospital Laboratory or other Health
Care Laboratory. | Hospital Laboratory or other Health
Care 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 safety
due to no direct patient contact. | No issues regarding chemical safety
due to no direct patient contact. |

Differences Chart with STA® - Liatest® D-Di (K964728) •

| Attributes or

characteristics	Device	Predicate Device
Indications for
Use	Diagnostica Stago,
STA® - Liatest® D-Di	Diagnostica Stago,
STA® - Liatest® D-Di
K964728
	Quantitative determination of D-
dimer in venous plasma (in 3.2%
sodium citrate). The assay 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.	Quantitative determination of D-
dimer in plasma. The assay can be
used to aid in the diagnosis of deep
venous thrombosis and pulmonary
embolism disease.

Similarities Chart with VIDAS® D-Dimer Exclusion™ (K040882) .

| Attributes or

characteristics	Device	Predicate Device
	Diagnostica Stago,
STA® - Liatest® D-Di	bioMérieux,
VIDAS® D-Dimer Exclusion™
K040882
Indications for
Use	Quantitative determination of D-
dimer in venous plasma (in 3.2%
sodium citrate). The assay 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.	Automated quantitative test for use
on the VIDAS instruments for the
immunoenzymatic determination of
fibrin degradation products (FbDP)
in human plasma (sodium citrate)
using ELFA technique (Enzyme
Linked Fluorescent Assay). The
assay is indicated for use in
conjunction with a clinical pretest
probability assessment model to
exclude deep vein thrombosis (DVT)
and pulmonary embolism (PE)
disease in outpatients suspected of
PE or DVT.

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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 or
characteristics	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)
Clinical
performances	For exclusion of PE on low and
moderate 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 and
moderate 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 Health
Care Laboratory.	Hospital Laboratory or other Health
Care 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 safety
due to no direct patient contact.	No issues regarding chemical safety
due to no direct patient contact.

Differences Chart with VIDAS® D-Dimer Exclusion™ (K040882) •

	Device	Predicate Device
Attributes or
characteristics	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 based
on the measurement of light
absorbance (at 540 nm) produced by
a suspension of microlatex particles
coated with specific mouse anti-
D-dimer
human
monoclonal
antibodies.	The assay combines a two-step
enzyme
immunoassay
sandwich
method with a final fluorescent
detection step (ELFA).
Analyzers	IVD analyzers of the STA® line.	VIDAS instruments

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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 %)

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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