(197 days)
The BTA stat test is an in vitro diagnostic immunoassay indicated for the qualitative detection of bladder turnor associated antigen in urine of persons diagnosed with bladder cancer. This test is indicated for use as an aid in the management of bladder cancer patients in conjunction with cystoscopy.
The BTA stat test is a qualitative test indicated for use as an aid in the management of bladder cancer patients in conjunction with cystoscopy.
The BTA stat test for bladder tumor associated antigen is an immunochromatographic assay utilizing monoclonal antibodies to specifically detect the presence of bladder tumor associated antigen in urine. Patient urine is added to the sample well and allowed to react with a colloidal gold-conjugated antibody. If the antigen is present in the sample, an antigen conjugate complex is formed and a line in the patient (P) test zone appears.
Here's a breakdown of the acceptance criteria and study information for the Bard BTA stat™ Test, based on the provided 510(k) summary:
Acceptance Criteria and Device Performance
The 510(k) summary for the Bard BTA stat™ Test does not explicitly state pre-defined acceptance criteria (e.g., "device must achieve X sensitivity and Y specificity"). Instead, it presents the device's performance metrics and implicitly asks the FDA to accept these results as substantially equivalent to the predicate device. The performance is primarily evaluated through clinical sensitivity and clinical specificity.
| Metric | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Clinical Sensitivity (Overall) | Adequate for its intended use as an aid in managing bladder cancer patients, comparable to or better than the predicate device. | For 220 patients with histological confirmation of bladder cancer: 66% |
| Clinical Sensitivity (by Stage) | Adequate per stage, especially for more advanced or aggressive disease. | Ta: 51%, T1: 90%, ≥T2: 88%, Tis: 61% |
| Clinical Sensitivity (by Grade) | Adequate per grade, especially for higher grades. | Grade 1: 42%, Grade 2: 66%, Grade 3: 83% |
| Monitoring Sensitivity (for patients with history of bladder cancer) | Adequate for recurrence monitoring. | 67% (95% CI: 60-73) |
| Clinical Specificity (Overall for subjects with no history of bladder cancer) | Adequate to minimize false positives in individuals without bladder cancer. | For 555 individuals: Overall 80% (calculated from Table VI: (1670.95 + 1050.93 + 1520.72 + 770.73 + 54*0.33) / 555) - Note: The document states 80% specifically for healthy individuals from Table VI, but the overall specificity for the 555 individuals needs careful calculation from the table. The document also states "The realite indicated that heathy inclivity in the was 20%, respective)", which implies a 80% healthy specificity. |
| Monitoring Specificity (for patients with history of bladder cancer, no evidence of disease) | Adequate for monitoring, comparable to or better than predicate device. | 70% (95% CI: 61-79) |
| Interference | No significant interference from common urine constituents, microbial contaminants, or therapeutic agents at physiologically relevant concentrations. | Many substances showed no interference at high levels. Bilirubin (unconjugated), Caffeine, Nicotine, Sodium chloride, Candida albicans, Acetaminophen, Acetyl Salicylic Acid, Phenazopyridine-HCl, Ioversol, Uriced showed interference at very high levels or exhibited negative interference. |
| High Dose Hook Effect (Prozone Effect) | No prozone effect. | No prozone effect up to 12,400 U/ml. |
| Reproducibility | Consistent results across different lots, readers, and days. | Nearly total agreement, with expected variability near the limit of detection. |
Study Details
Here's the breakdown of the study components:
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Sample sizes used for the test set and the data provenance:
- Clinical Sensitivity:
- Initial cohort: 220 patients with histologically confirmed bladder cancer.
- Subset for comparison with Bard BTA test: 181 patients from the sensitivity cohort.
- Subset for comparison with Voided Urine Cytology (VUC): 131 patients (with histologically confirmed bladder cancer).
- Data Provenance: Samples were "collected from 5 different may and the no have you intelles. United States." (This phrasing is a bit ambiguous, but suggests multiple sites within the US, prospectively collected for the study). Samples were stored frozen (-80°C) until tested.
- Clinical Specificity:
- No history of bladder cancer cohort: 555 individuals.
- History of bladder cancer - No Evidence of Disease cohort: 107 patients. This cohort's no evidence of disease was confirmed by cystoscopy and/or biopsy.
- Data Provenance: Samples were "collected from 5 different may and the no have you intelles. United States." (as above). Stored frozen (-80°C).
- Clinical Sensitivity:
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The primary ground truth for clinical sensitivity was histological confirmation of bladder cancer. This implies that pathology reports from pathologists were used. The number of pathologists involved is not specified, but it's standard practice in clinical studies for a pathologist to confirm diagnosis.
- For the "History of Bladder Cancer - No Evidence of Disease" specificity cohort, ground truth was established by cystoscopy and/or biopsy. The experts performing these procedures (e.g., urologists) and interpreting the results (e.g., pathologists for biopsies) are not explicitly quantified or qualified in this summary.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- The summary does not explicitly mention an adjudication method for the final diagnosis (ground truth). The reliance on "histological confirmation" and "cystoscopy and/or biopsy" suggests that these established diagnostic methods served as the definitive ground truth, implying standard clinical practice for diagnosis rather than a specific multi-reader adjudication process for the test device interpretation. The device itself is a qualitative assay with a direct positive/negative result.
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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 involving human readers and AI assistance was not mentioned. This device is an in-vitro diagnostic (IVD) assay designed for direct interpretation (presence/absence of a line), not an AI-powered image analysis tool requiring human reader interpretation in comparison.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, this entire study is a standalone performance evaluation of the Bard BTA stat™ Test as an algorithm/device only without a human-in-the-loop component for interpretation. The device provides a direct qualitative result (positive or negative based on line appearance).
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- Pathology: "Histological confirmation" was the primary ground truth for bladder cancer diagnosis (clinical sensitivity).
- Clinical Outcomes/Procedures: "Cystoscopy and/or biopsy" confirmed "no evidence of disease" for defining part of the specificity cohort.
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The sample size for the training set:
- The document describes performance studies, which are equivalent to test set evaluations. It does not specify a separate training set for the development of the Bard BTA stat Test itself. This is typical for IVD devices where the analytic and clinical performance are assessed once the device's formulation and design are finalized. The device operates based on a fixed immunological reaction rather than a machine learning algorithm that requires a separate training phase.
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How the ground truth for the training set was established:
- As there's no mention of a separate "training set" for the device's development in the context of machine learning, this question isn't directly applicable. The device's "training" or development involved optimizing the immunochromatographic assay components, which would have been done using known positive and negative samples, but these are not described as a "training set" in the sense of a machine learning model.
§ 866.6010 Tumor-associated antigen immunological test system.
(a)
Identification. A tumor-associated antigen immunological test system is a device that consists of reagents used to qualitatively or quantitatively measure, by immunochemical techniques, tumor-associated antigens in serum, plasma, urine, or other body fluids. This device is intended as an aid in monitoring patients for disease progress or response to therapy or for the detection of recurrent or residual disease.(b)
Classification. Class II (special controls). Tumor markers must comply with the following special controls: (1) A guidance document entitled “Guidance Document for the Submission of Tumor Associated Antigen Premarket Notifications (510(k)s) to FDA,” and (2) voluntary assay performance standards issued by the National Committee on Clinical Laboratory Standards.