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Found 6 results
510(k) Data Aggregation
(155 days)
WA 98104
Re: K161947
Trade/Device Name: Chagas Detect™ Plus Rapid Test Regulation Number: 21 CFR 866.3870
The Chagas Detect™ Plus (CDP) Rapid Test is a rapid immunochromatographic strip assay for the qualitative detection of human IgG antibodies to Trypanosoma cruzi (T. cruzi) in human serum and whole blood matrices (venous and capillary (finger prick) whole blood). CDP is a non-invasive diagnostic test for use in a primary care setting by personnel trained to obtain whole blood or serum samples. Reactive test results will be presumptive evidence of infection with T. cruzi. The CDP when used in conjunction with other serological and clinical information is useful for the diagnosis of individuals with Chagas disease. Definitive diagnosis of an acute phase infection (including acute congenital infection) must be made by alternative methods, e.g., hemoculture, blood smear. This test is not intended for use on cord blood or for screening blood or plasma donors.
The Chagas Detect™ Plus (CDP) Rapid Test is a rapid immunochromatographic strip assay for the qualitative detection of human IgG antibodies to Trypanosoma cruzi (T. cruzi) in human serum and whole blood matrices (venous and capillary (finger prick) whole blood).
The provided text is a 510(k) premarket notification letter from the FDA regarding the Chagas Detect™ Plus Rapid Test. It confirms the device's substantial equivalence to legally marketed predicate devices.
However, the document does not contain any information about a study that proves the device meets specific acceptance criteria in the context of an AI/ML medical device submission. It is for a rapid immunochromatographic strip assay, which is a laboratory diagnostic test, not an AI/ML device. Therefore, the requested information about acceptance criteria, study details, expert involvement, and ground truth for an AI/ML model's performance evaluation cannot be extracted from this document.
The document discusses:
- The device name: Chagas Detect™ Plus Rapid Test
- Its intended use: Qualitative detection of human IgG antibodies to Trypanosoma cruzi (T. cruzi) in human serum and whole blood.
- Regulatory information: Regulation Number, Name, Class, and Product Code.
- The FDA's determination of substantial equivalence.
- General controls provisions and other regulatory requirements for the device.
To fulfill the request, a document describing an AI/ML medical device's performance study would be necessary.
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(177 days)
November 14, 2014
Re: K141341
Trade/Device Name: CL Detect™ Rapid Test Regulation Number: 21 CFR 866.3870
The CL Detect™ Rapid Test is a qualitative, in vitro immunochromatographic assay for the rapid detection of Leishmania species antigen in ulcerative skin lesions. The test is intended for use with dental broach samples from less than four month old ulcerative skin lesions that are obtained from patients with suspected cutaneous leishmaniasis (CL). The test targets the peroxidoxin antigen of Leishmania species that may cause CL. The CL DetectTM Rapid To aid in the diagnosis of CL, and must be interpreted within the context of all relevant clinical and laboratory findings.
Not Found
The provided document is an FDA 510(k) clearance letter for the "CL Detect™ Rapid Test" and its Indications for Use statement. It declares the device's substantial equivalence to a predicate device but does not contain information about acceptance criteria, device performance studies, sample sizes, expert qualifications, or ground truth establishment.
Therefore, I cannot fulfill your request to describe the acceptance criteria and the study that proves the device meets them based on the provided text. The document only states the intended use of the device:
Device Name: CL Detect™ Rapid Test
Indications for Use: The CL Detect™ Rapid Test is a qualitative, in vitro immunochromatographic assay for the rapid detection of Leishmania species antigen in ulcerative skin lesions. The test is intended for use with dental broach samples from less than four-month-old ulcerative skin lesions that are obtained from patients with suspected cutaneous leishmaniasis (CL). The test targets the peroxidoxin antigen of Leishmania species that may cause CL. The CL Detect™ Rapid Test is to aid in the diagnosis of CL, and must be interpreted within the context of all relevant clinical and laboratory findings.
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(1057 days)
Leishmania Real-time Polymerase Chain Reaction Diagnostic Assay,
Trypanosoma spp. serological reagents
866.3870
Detrick, MD 21702-5009
Re: K081868 Trade/Device Name: SMART Leish PCR Assay Regulation Number: 21 CFR 866.3870
The SMART Leish is a qualitative diagnostic real-time PCR test for the rapid detection of Leishmania species and the identification of L. major in skin lesion scrapings and punch biopsies from individuals suspected of having cutaneous leishmaniasis. The test utilizes real-time polymerase chain reaction assay on the Cepheid SmartCycler® II Dx to detect Leishmania species and L. major. The SMART Leish is indicated for use in patients with clinical presentations and travel history.
The SMART Leish consists of an assay reagent kit and assay definition files for the polymerase chain reaction (PCR) instrument platform. The kit contains sufficient reagents, in lyophilized bead form, to qualitatively assay 50 clinical samples for both Leishmania genus and L. major targets. Additional required accessories that are specified include the PCR instrument platform, a deoxyribonucleic acid (DNA) purification kit, and a positive extraction control. The device components and required accessories are listed as follows.
For the Leishmania assays, a tissue specimen (skin scraping or punch biopsy) from an individual suspected of being infected with Leishmania species or L. major is collected in 70% or 100% ethanol, and the DNA is extracted from the specimen using the Qiagen QlAamp DNA Mini Kit. An aliquot of this DNA is tested using the Leishmania genus assay, which will amplify a portion of DNA encoding the Leishmania species 16S ribosomal ribonucleic acid (rRNA) gene if present. Amplified targets are detected using a TaqMan® hybridization probe with 6-carboxyfluorescein.(FAM) reporter dye (517 nm) and a Black Hole Quencher® (BHQ). This assay also contains a positive internal control consisting of a nonsensical, non-naturally occurring DNA sequence, with Texas Red reporter dye (615 nm) and BHQ, used to detect evidence of PCR inhibition and confirm the integrity of assay reagents in negative specimens. If the sample tests positive for Leishmania species, another aliquot of DNA may be tested using the L. major assay, which will amplify a portion of DNA encoding the GPI gene that is specific to L. major. Amplified targets are detected using a TaqMan hybridization probe with FAM reporter dye and a BHQ. The DNA amplification, detection of fluorescence, and interpretation of signals are done automatically by the SmartCycler instrument for each assay. The thermocycling protocols take approximately 45-55 minutes.
Here's a breakdown of the acceptance criteria and the study details for the SMART Leish device, based on the provided text:
Acceptance Criteria and Reported Device Performance
The document does not explicitly state pre-defined "acceptance criteria" in terms of numerical thresholds for sensitivity, specificity, or agreement. However, the reported performance suggests what the submitter considered acceptable for demonstrating substantial equivalence. The provided data focuses on the clinical performance and various analytical performance metrics.
Performance Metric | Acceptance Criteria (Inferred) | Reported Device Performance (Leishmania Genus Assay) | Reported Device Performance (L. major Assay) |
---|---|---|---|
Clinical Performance | Demonstrated effectiveness in detecting Leishmania species and identifying L. major in suspected cutaneous leishmaniasis cases. | Sensitivity: 223/225 = 99.1% | |
Specificity: 58/87 = 66.7% | Sensitivity: 92/96 = 95.8% | ||
Specificity: 83/91 = 91.2% | |||
Analytical Reactivity/Inclusivity | Robust positive results with target Leishmania strains. | 100% positive results for 36 Leishmania strains. | 100% positive results for 11 L. major strains. |
Analytical Specificity (Cross-Reactivity) | No significant cross-reactivity with non-target organisms. | 98.3% (2 false positives out of 85 non-target samples). Minimal cross-reactivity with C. fasciculata. | 100% (0 false positives out of 25 non-L. major samples). |
Analytical Sensitivity (LOD) | Lowest detectable amount of DNA/parasites with ≥95% consistency. | Assay LOD: 0.14 pg | |
eLOD: 250 parasites | Assay LOD: 2.1 pg | ||
eLOD: 1,000 parasites | |||
Reproducibility | Consistent results across different laboratories, operators, and days, for various concentrations of purified DNA, cultured parasites, and mock human samples. | Overall Agreement for Mock Human Samples: 98.6% (71/72) | Overall Agreement for Mock Human Samples: 100% (41/41) |
Interfering Substances | Performance not significantly affected by common PCR inhibitors at clinically relevant concentrations. | See Table 10 for specific concentrations and non-inhibition limits. | Not explicitly detailed for L. major assay in this section. |
Study Details
2. Sample size used for the test set and the data provenance
- Leishmania Genus Assay: 312 prospective specimens (225 positive, 87 negative)
- Leishmania major Assay: 187 prospective specimens (96 positive, 91 negative)
- Data Provenance: Multi-center, retrospective clinical study conducted at two military U.S. hospital sites. The patient population consisted entirely of military personnel who were at the time, or had previously been, deployed to Southwest Asia—primarily Afghanistan and Iraq.
3. 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.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
The document does not specify an adjudication method. The ground truth was established by "culture and/or microscopy." In cases of discrepancy (false positives by SMART Leish), sequencing methods were used for further investigation, but this is a reconciliation rather than a primary adjudication method for establishing initial ground truth.
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
- No, an MRMC comparative effectiveness study was not done.
- This device is a diagnostic assay (PCR test), not an AI-assisted imaging or interpretation tool for human readers. Therefore, the concept of "human readers improve with AI vs without AI assistance" does not apply here.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Yes, a standalone performance study was done. The SMART Leish is a fully automated diagnostic assay where "DNA amplification, detection of fluorescence, and interpretation of signals are done automatically by the SmartCycler instrument for each assay." The clinical performance data presented (Tables 2 and 3) reflects this standalone performance against the clinical truth.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
The ground truth for the clinical performance study (test set) was established using culture and/or microscopy. For discordant results (false positives by SMART Leish compared to initial ground truth), sequencing methods were used for further analysis.
8. The sample size for the training set
The document does not specify a "training set" or its size. As a PCR diagnostic assay, it would typically undergo a development and optimization phase, but the document focuses on validation/testing. The "analytical reactivity" and "analytical specificity" studies used various Leishmania strains and non-target organisms, which could be considered part of the development/validation process.
- Analytical Reactivity Study: 36 Leishmania strains.
- Analytical Specificity Study: 121 DNA samples (11 L. major, 25 non-L. major, 85 non-target organisms from various categories).
9. How the ground truth for the training set was established
Since no explicit "training set" is mentioned in the context of machine learning, the establishment of ground truth would refer to the characteristics of the strains used in analytical studies. These would be:
- For Leishmania strains: Identity established through standard microbiological and molecular characterization methods (e.g., taxonomic classification, phenotypic and genotypic analysis, likely confirmed by sequencing).
- For non-target organisms: Identity established through standard microbiological and molecular characterization methods.
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(567 days)
Serological reagents (21 CFR 866.3870)
Assay Class: I (general controls)
4 Predicate Device
The
5 2009
Re: K072732
Trade/Device Name: ORTHO® T. cruzi ELISA Test System Regulation Number: 21 CFR 866.3870
ORTHO T. cruzi ELISA Test System is an enzyme-linked immunosorbent assay for the in vitro qualitative detection of antibodies (Immunoglobulin G) to Trypanosoma cruzi (T. cruzi) in human adult serum (glass, plastic, or serum separator tubes) and plasma (EDTA, lithium heparin or citrate) using whole-cell lysate antigens. Reactive assay results are presumptive evidence of past infection, and in conjunction with other serological and clinical information, may be used for the laboratory diagnosis of individuals with Chagas' disease.
Definitive diagnosis of an acute phase of infection (including acute congenital infection) must be made by alternate methods, e.g., hemoculture, blood smear.
This test is not intended for use on samples of cord blood or screening blood or plasma donors.
The ORTHO T. cruzi ELISA Test System is an enzyme-linked immunosorbent assay (ELISA). ELISA technology utilizes the principle that antibodies bound to the solid phase can be detected by complementary antibodies or antigens labeled with an enzyme capable of acting on a chromogenic substrate. When substrate is applied, the presence of antigens or antibodies can be detected by development of a colored end product. The optical densities are read spectrophotometrically.
This ELISA was developed to detect human antibodies to T. cruzi in serum and plasma. The assay utilizes microwells coated with a whole-cell lysate containing T. cruzi antigens as the solid phase. The assay procedure is a three-stage test carried out in a microwell coated with lysate (antigens) prepared from T. cruzi. In the first stage, test specimen, Negative Control, and Positive Calibrator are diluted directly in the test well containing Specimen Diluent, and incubated for a specified length of time. If antibodies to T. cruzi are present, antigen-antibody complexes will form on the microwell surface. If antibodies to T. cruzi are absent, complexes will not form. Unbound antibodies in the sample will be removed during the subsequent wash step.
In the second stage, murine monoclonal antibody conjugated with Horseradish Peroxidase (Conjugate) is added to the test well. The Conjugate binds specifically to the antibody portion of the antigen-antibody complex. If complexes are not present, the unbound Conjugate is removed by the subsequent wash step.
In the third stage, an enzyme detection system composed of o-phenylenediamine (OPD) and hydrogen peroxide is added to the test well. If bound Conjugate is present, the OPD with be oxidized, resulting in a colored end product. Sulfuric acid is then added to stop the reaction. The color intensity depends on the amount of bound Conjugate and, therefore, is a function of the concentration of antibodies to T. cruzi present in the specimen. The intensity of color in the substrate solution is then determined with a microwell reader (spectrophotometer) designed to measure light absorbance in a microwell.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
Device: ORTHO® T. cruzi ELISA Test System
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state "acceptance criteria" in a separate section with specific numerical thresholds for performance metrics. However, the performance study data implicitly demonstrates the device's acceptable performance by showing strong agreement with established methods and probable T. cruzi antibody status. The key performance metrics are Positive Percent Agreement (PPA) and Negative Percent Agreement (NPA).
Given the context of a 510(k) submission, the implicit acceptance criteria would be for the device to perform comparably to, or demonstrate a high level of agreement with, the established comparator methods and the "most probable T. cruzi antibody status."
Metric | Implicit Acceptance Criteria (based on predicate/comparator performance expectations) | Reported Device Performance (vs. Most Probable T. cruzi Antibody Status) |
---|---|---|
Positive Percent Agreement (PPA) | High agreement (e.g., >90%) with probable positive cases | 98.92% (92/93) (Overall) |
(95% CI: 94.15% - 99.97%) | ||
Negative Percent Agreement (NPA) | High agreement (e.g., >95%) with probable negative cases | 99.39% (975/981) (Overall) |
(95% CI: 98.67% - 99.78%) | ||
Positive Percent Agreement (PPA) (Serological Presumed Positive Population) | High agreement (e.g., >95%) with probable positive cases in this specific population | 100% (662/662) |
(95% CI: 99.44% - 100%) | ||
Negative Percent Agreement (NPA) (Serological Presumed Positive Population) | High agreement (e.g., >95%) with probable negative cases in this specific population | 98.65% (146/148) |
(95% CI: 95.20% - 99.84%) |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set:
- High and Low Risk Subjects Study: N = 1074 subjects
- Serological Presumed Positive Population Study: N = 810 specimens
- Data Provenance:
- Country of Origin: The "Serological Presumed Positive Population" study explicitly states specimens were obtained from endemic countries: Bolivia (17.8%), Brazil (24.7%), Chile (10.6%), Guatemala (2.2%), Mexico (32.5%), and Nicaragua (12.2%). The provenance for the "High and Low Risk" subjects is not explicitly stated, but given T. cruzi is endemic to Latin America, it's highly likely they came from similar regions or populations with risk factors associated with these regions.
- Retrospective or Prospective: Not explicitly stated, but the description of "specimens from 1074 subjects" and "specimens obtained from" suggests these were pre-collected samples, which typically implies a retrospective study design.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- The document does not specify the number of experts used to establish the ground truth.
- It refers to "a pre-specified testing algorithm" involving the ORTHO T. cruzi ELISA Test System, a comparator T. cruzi IFA (indirect immunofluorescence assay), and supplemental T. cruzi RIPA (radioimmunoprecipitation assay) testing to determine the "most probable T. cruzi antibody status." This implies a laboratory-based algorithm rather than subjective expert interpretation for each individual case ground truth.
- Qualifications of Experts: Not specified. However, the reliance on established serological methods (IFA, RIPA) suggests that interpretation would be done by qualified laboratory personnel following established protocols, though individual "experts" for ground truth adjudication are not mentioned.
4. Adjudication Method for the Test Set
The adjudication method used to establish the "most probable T. cruzi antibody status" for the test sets was a pre-specified testing algorithm rather than an expert consensus method like 2+1 or 3+1.
- For High and Low Risk Subjects:
- Specimens negative with both the ORTHO T. cruzi ELISA and the T. cruzi IFA were assigned a "most probable T. cruzi antibody status of negative" (if not tested with RIPA).
- Specimens tested with RIPA were assigned a most probable status of positive, negative, or indeterminate based on RIPA results.
- For Serological Presumed Positive Population:
- Specimens that were ORTHO T. cruzi ELISA repeatedly reactive AND positive with the T. cruzi IFA were assigned a "most probable T. cruzi antibody status of positive" without further RIPA testing.
- All specimens negative with both assays OR with discordant results between the two assays were tested with the T. cruzi RIPA, and their status was assigned "based upon the RIPA results."
This method essentially uses a hierarchical testing algorithm with RIPA as a confirmatory test for ambiguous cases, which acts as the adjudicator.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance
- No, an MRMC comparative effectiveness study was not done.
- This device is an ELISA diagnostic kit, which is an in vitro diagnostic (IVD) assay to detect antibodies in serum/plasma. It is not an AI-assisted diagnostic device that would involve human readers interpreting images or data with or without AI assistance. Therefore, the concept of "human readers improve with AI vs. without AI assistance" does not apply here.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) Was Done
- Yes, the performance presented in the report is for the device operating in a standalone capacity (algorithm only).
- The ORTHO T. cruzi ELISA Test System is an automated/semi-automated in vitro diagnostic assay. The results (optical densities) are read spectrophotometrically, and the interpretation (reactive/nonreactive) is based on a pre-defined cutoff. While human operators are involved in running the assay (pipetting, washing, loading), the diagnostic decision itself from the optical density reading is based on the device's internal algorithm/parameters, not human interpretation of a raw signal. The performance metrics (PPA, NPA) directly reflect this standalone assay performance against the established ground truth.
7. The Type of Ground Truth Used
The ground truth used was a "most probable T. cruzi antibody status" established by a pre-specified testing and interpretation algorithm involving:
- The ORTHO T. cruzi ELISA Test System itself
- A comparator T. cruzi IFA
- Supplemental T. cruzi RIPA testing (Radioimmunoprecipitation Assay) as a confirmatory assay.
This approach combines multiple serological methods, with RIPA acting as the highest tier for ambiguous results, to arrive at a "most probable" truth, which is a form of composite reference standard or multi-test algorithm ground truth.
8. The Sample Size for the Training Set
- The document does not specify any sample size for a training set.
- This is common for in vitro diagnostic (IVD) devices like ELISA kits, which are often developed and optimized using a variety of samples during their analytical validation phase, but the rigorous performance evaluation for regulatory submission typically focuses on a distinct clinical validation (test) set. The concepts of "training set" and "test set" are more explicitly separated for machine learning/AI models.
9. How the Ground Truth for the Training Set Was Established
- Since a "training set" is not explicitly mentioned or detailed in the provided document, there is no information on how its ground truth was established. If one were used in development, it would likely follow similar principles of using established serological methods and clinical information for sample characterization.
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(447 days)
| Introduction | According to the requirements of 21 CFR 866.3870
Rockville MD 20850
K023889 Re:
Trade/Device Name: Chagatest ELISA rec. v.3.0 Regulation Number: 21 CFR § 866.3870
The Wiener Laboratory enzyme-linked Immunosorbent assay (ELISA) recombinante V. 3.0 test system is a manual and automated instrument assay for the qualitative detection of total antibodies (IgG and IgM) to Trypanosoma cruzi in human serum and plasma (EDTA, heparin, or Citrate) using recombinant antigens of T. cruzi. Reactive results are presumptive evidence of present or past infection with Trypanosoma cruzi.
In this qualitative technique for the detection of antibodies anti-T. Cruzi, the sample is diluted in the wells in which recombinant antigens starting from specific proteins from the epimastigote and trypomastigote stages of the T. cruzi corresponding to highly conserved zones are immobilized. These antigens are proteins with aminoacid sequences repeated in tandem. SAPA (shed acute phase antigen) antigens detect antibodies in 93% of the patients' sera during the acute phase of the infection. It comes from the trypomastigote-bloodstream form of the parasite; #1, #2 and #30 antigens detect antibodies in chronic patients; #13 and #36 specially detect antibodies in sera both from acute and chronic patients.
If the sample contains Chagas' antibodies, they bind to the antigens bound to the support. The unbound antigens and antibodies are removed by washing, after which anti-human immunoglobulin antibodies conjugated to peroxidase are added. If a reaction was produced in the first step of the process, the conjugate is bound. After a new washing step and the addition of a chromogenic substrate and stopping reagent, specimens containing antibodies to T. cruzi produce a color reaction which can be read with a standard ELISA plate reader.
Here's an analysis of the provided text to extract information about acceptance criteria and the study that proves the device meets them:
Device Name: Chagatest ELISA recombinante v.3.0 (also referred to as Wiener lab Chagatest ELISA rec. v.3.0)
Intended Use: Qualitative detection of antibodies to Trypanosoma cruzi (causative agent of Chagas' disease) in human serum and plasma. Useful in establishing prior exposure to T. cruzi and as an aid in diagnosis.
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state pre-defined acceptance criteria in a dedicated section. However, it presents "Performance Characteristics" including "Relative Sensitivity," "Relative Specificity," and "Relative Agreement," with specified confidence intervals. It also highlights an overall relative sensitivity of 97.9% and relative specificity of 97.8% (after resolution of discordant samples) or 97.9% and 97.8% (before resolution of discordant samples) from a combined analysis of multiple sites.
Given the context of a 510(k) summary seeking substantial equivalence, implicit acceptance criteria would likely involve demonstrating high relative sensitivity and specificity that are comparable to or better than predicate devices and meet general diagnostic accuracy expectations for such assays. While not explicitly stated as "acceptance criteria," the reported performance values are what would be used by the FDA to determine substantial equivalence.
Performance Metric | Reported Device Performance (after resolution unless specified) |
---|---|
Relative Sensitivity | 97.9% (95% CI: 95.6 - 99.1%) |
Relative Specificity | 97.8% (95% CI: 97.0 - 98.5%) |
Relative Agreement | 97.9% (95% CI: 97.1 - 98.5%) |
Intra-assay Precision (%CV) - Manual | 4.8% to 19.7% |
Intra-assay Precision (%CV) - Automated | 7.7% to 14.0% |
Inter-assay Precision (%CV) - Manual | 7.4% to 26.4% |
Inter-assay Precision (%CV) - Automated | 15.7% to 29.2% |
2. Sample Sizes Used for the Test Set and Data Provenance
The test set consisted of multiple studies performed at different sites. The total sample size and data provenance are:
Study/Site | Sample Size | Data Provenance |
---|---|---|
1.1 Comparison with MERIDIAN (U.S. low-risk) | 500 | U.S. (Iowa), low-risk individuals (retrospective, assumed) |
1.2 Comparison with MERIDIAN (Mexican Blood Bank) | 83 | Mexican Blood Bank (Guadalajara and Iowa) (retrospective, assumed) |
1.3 Comparison with ABBOTT (Argentina) | 790 | Argentina (Rosario, SF) (retrospective, assumed) |
1.4 Comparison with ABBOTT (Argentina) | 286 | Argentina (Buenos Aires, Hospital de Clínicas) (retrospective, assumed) |
1.5 Comparison with ABBOTT and MERIDIAN | 90 | Unspecified; panel of sera (retrospective, assumed) |
2.1 Specificity (U.S. low-risk) | 500 | U.S. (Iowa Hospitals, Iowa City, USA) (retrospective, assumed) |
2.2 Sensitivity (Endemic Area, Argentina) | 118 | Argentina (Centro de Enfermedades y Patología Regional, Santiago del Estero), selected reactive specimens (retrospective, assumed) |
2.3 Sensitivity (Chile) | 51 | Chile (Instituto de Ciencias Biomedical, Facultad de Medicina, Universidad de Chile, Santiago de Chile) (retrospective, assumed) |
2.4 ISP Evaluation (Chile) | 150 | Chile (ISP, Santiago de Chile) (retrospective, assumed) |
2.5 High Prevalence (Salta, Argentina) | 58 | Argentina (San Carlos, Provincial de Salta), blood bank specimens (retrospective, assumed) |
2.5 High Prevalence (Salta, Argentina) - IHA | 52 | Argentina (Salta), IHA-reactive specimens (retrospective, assumed) |
2.6 Specificity (Buenos Aires, Argentina) | 286 | Argentina (Hospital de Clínicas, Buenos Aires) (retrospective, assumed) |
2.7 Blood Donors (Sao Paulo, Brazil) | 1236 | Brazil (Hemocentro de Sao Paulo, Sao Paulo), blood donors (retrospective, assumed) |
2.7 Blood Donors (Sao Paulo, Brazil) - Panels | 300 | Brazil (Sao Paulo), selected reactive/non-reactive panels (retrospective, assumed) |
2.8 Sensitivity Panel (Sao Paulo, Brazil) | 188 | Brazil (Centro de Imunologia e Imunogenetica, Sao Paulo), sensitivity panel (retrospective, assumed) |
2.9 Blood Donors (Sao Paulo, Brazil) | 400 | Brazil (Centro de Imunologia e Imunogenetica, Sao Paulo), blood donors (retrospective, assumed) |
2.10 Study (Rio de Janeiro, Brazil) | 914 | Brazil (Fundação Oswaldo Cruz, Rio de Janeiro), reactive and non-reactive specimens (retrospective, assumed) |
2.11 Xenodiagnosed Positive | 70 | Unspecified, xenodiagnosed positive specimens (retrospective, assumed) |
5. Patient Populations (Salta, Argentina) | 52 | Argentina (Salta), IHA-reactive specimens (retrospective, assumed) |
5. Patient Populations (Santiago del Estero, Argentina) | 118 | Argentina (Santiago del Estero), IHA/IFA/ELISA-reactive specimens (retrospective, assumed) |
5. Patient Populations (Xenodiagnosed) | 70 | Unspecified, xenodiagnosed positive individuals (retrospective, assumed) |
5. Pregnant Women (Santiago del Estero, Argentina) | 368 | Argentina (Santiago del Estero), pregnant women (retrospective, assumed) |
Total combined sample size for comparative effectiveness/performance studies appears to be over 5000 specimens across various studies. All data appears to be retrospective based on the nature of the studies (testing existing specimens, panels, or comparing against established methods). The countries of origin include Argentina, Mexico, Chile, and Brazil, with some studies also including low-risk individuals from the U.S.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not explicitly state the number or specific qualifications of individual experts. However, it describes that ground truth was established using:
- Comparison methods: Predicate devices (MERIDIAN Premier™ Chagas' IgG ELISA, ABBOTT Chagas Antibody EIA) were used as primary comparators.
- Confirmatory/Reference tests: Radio Immuno Precipitation Assay (RIPA), Indirect Hemagglutination Assay (IHA), Immunofluorescence Assay (IFA), and xenodiagnosis were used as reference methods, particularly for resolving discordant results or establishing the status of selected panels.
- Clinical context: Specimens were often from "patients with confirmed Chagas' disease by xenodiagnosis, IHA and IFA," "blood donors," or "patients from an endemic area."
- The reference tests (IHA, IFA, RIPA, xenodiagnosis) are typically performed and interpreted by experienced laboratory personnel or medical professionals.
4. Adjudication Method for the Test Set
Adjudication methods are described for discordant results:
- Discordant results between the Wiener lab ELISA and predicate devices were often adjudicated using reference methods like RIPA, IHA, and/or IFA.
- For example: "Out of 5 specimens with discordant results, all 5 were reactive by Wiener lab ELISA and a RIPA, but non-reactive by Meridian." (Section 1.2)
- "Of the 12 specimens with discordant results... 6 specimens were reactive by Wiener lab Chagatest ELISA rec.v.3.0 and non-reactive by Abbott Chagas Antibody EIA. Out of those 6 specimens, 3 were reactive by IFA." (Section 1.3)
- "7 specimens were reactive by Wiener lab ELISA, reactive by IHA / IFA / RIPA and/or Meridian ELISA and non-reactive by Abbott ELISA." (Section 1.5a)
The specific process for how these reference results were used to adjudicate a final ground truth (e.g., majority vote, hierarchy of tests) is not explicitly detailed but implied that the consensus or superior reference test determined the final status.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not explicitly described. This is an in vitro diagnostic device for laboratory use, and its performance is typically assessed by comparing its numerical output (e.g., signal/cut-off ratio) to a threshold and then to gold standard/reference methods, rather than human readers interpreting images or data for diagnosis. The studies focused on comparing the device's diagnostic accuracy (sensitivity, specificity, agreement) to other assays and established reference methods.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
Yes, the studies reported are standalone performance evaluations of the Wiener lab Chagatest ELISA recombinante v.3.0. The "algorithm" here refers to the ELISA assay itself, which generates quantitative results (absorbance, s/c ratio) that are then interpreted against a predefined cutoff. The performance metrics (relative sensitivity, specificity, agreement) measure the device's accuracy in identifying positive or negative samples independently, without direct human intervention in the interpretation of each test result beyond comparing it to the cutoff. The studies compare the device's output to other test systems.
7. The Type of Ground Truth Used
The ground truth for the test sets was established using a combination of:
- Expert Consensus/Reference Methods: Primarily through established serological tests like Indirect Hemagglutination Assay (IHA), Immunofluorescence Assay (IFA), Radio Immuno Precipitation Assay (RIPA), and in some cases, previous ELISA results from other reference systems.
- Pathology/Outcomes Data (Indirectly): Xenodiagnosis, a biological method for detecting T. cruzi infection, was used for some "confirmed Chagas' disease" cases (e.g., Section 2.3, 2.11, 5). This can be considered a strong indicator of true infection.
- Clinical context: Patients from endemic areas and those with confirmed Chagas' disease were used to ensure the presence of antibodies, while low-risk individuals were used for specificity studies.
Therefore, the ground truth is a composite ground truth, derived from multiple established diagnostic methods and clinical confirmation strategies.
8. The Sample Size for the Training Set
The document does not specify a separate "training set" or "validation set" in the context of machine learning model development. This is an ELISA kit, which is a biochemical assay, not a machine learning algorithm that requires a training phase. The "studies" described are performance evaluations against established predicate devices and reference methods using various clinical samples. The "training" data for such a kit would implicitly be the data used during its development and optimization, which is not detailed here. The studies provided demonstrate the device's performance on various patient populations, which serves as a clinical validation.
9. How the Ground Truth for the Training Set Was Established
As noted above, this is an ELISA assay, not a machine learning model, so the concept of a "training set" ground truth in the AI context does not directly apply. The establishment of ground truth for the samples used in the performance evaluations (analogous to a test set in ML) is described in point 7 (composite ground truth from various reference methods and clinical confirmation).
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(201 days)
Name: Kalazar Detect™ Rapid Test for the Detection of Visceral Leishmaniasis Regulation Number: 21 CFR 866.3870
The Kalazar Detect™ Test is a rapid immuno-chromatographic strip assay for the qualitative detection of antibodies to members of L. donovani complex in human serum. This test is intended for laboratory or professional in vitro diagnostic use only.
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This document is an FDA 510(k) clearance letter for the "Kalazar Detect™ Rapid Test for the Detection of Visceral Leishmaniasis." As such, it primarily focuses on the regulatory approval and substantial equivalence to a predicate device. It does not contain detailed information about a comprehensive study proving the device meets specific acceptance criteria in the manner one might find for a more complex diagnostic or AI-based device.
Therefore, many of the requested fields cannot be directly extracted from this document because the letter does not include the detailed study design and results for performance evaluation.
However, I can provide the information that is present or can be inferred:
1. Table of Acceptance Criteria and Reported Device Performance:
This document does not explicitly state specific numerical acceptance criteria (e.g., sensitivity, specificity thresholds) or a direct performance table for the Kalazar Detect™ Rapid Test. The clearance is based on substantial equivalence to legally marketed predicate devices.
2. Sample Size Used for the Test Set and Data Provenance:
This information is not provided in the FDA clearance letter. It would typically be found in the manufacturer's 510(k) submission, which is not included here.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications:
This information is not provided in the FDA clearance letter. Ground truth for diagnostic tests typically relies on established clinical diagnoses or reference methods, but the specifics of how this was established for the performance evaluation are not detailed here.
4. Adjudication Method for the Test Set:
This information is not provided in the FDA clearance letter.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done:
This is a rapid immunoassay kit. An MRMC study is generally relevant for imaging or interpretation-heavy diagnostics where human reader performance is a key variable. Given the nature of a rapid immunochromatographic strip assay, an MRMC study is highly unlikely to have been performed or relevant in the context of improving human reader performance with AI assistance. The device itself is not an AI algorithm.
6. If a Standalone (algorithm only without human-in-the-loop performance) was done:
The Kalazar Detect™ Test is a rapid immunoassay kit, not an AI algorithm. Therefore, the concept of "standalone performance" for an algorithm is not applicable here. The device is designed for professional in vitro diagnostic use, meaning a human interprets the visual result on the strip.
7. The Type of Ground Truth Used:
While not explicitly stated in the letter, for an in vitro diagnostic test for Leishmaniasis antibodies, the ground truth would typically be established by a combination of clinical diagnosis (e.g., symptoms, geographic exposure) and confirmation by a validated reference method, such as microscopy, PCR, or culture for L. donovani in patient samples.
8. The Sample Size for the Training Set:
This information is not provided in the FDA clearance letter. For an immunoassay, the concept of a "training set" as understood in machine learning is not directly applicable. Instead, the device development would involve various stages of prototype testing and optimization using relevant biological samples.
9. How the Ground Truth for the Training Set Was Established:
This information is not provided in the FDA clearance letter. Similar to the test set, the "ground truth" for samples used during development would be established through robust reference methods for diagnosing Visceral Leishmaniasis.
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