(90 days)
BD BBL Sensi-Disc Antimicrobial Susceptibility Test (AST) Discs are used in the semi-quantitative agar diffusion test method for in vitro susceptibility testing.
BD BBL Sensi-Disc Lefamulin Disc 20 µg (LMU-20) can be used to determine susceptibility to Lefamulin against the following bacteria, as described in the FDA-approved package insert for this antimicrobial agent.
Active in vitro and in Clinical Infections Against: Gram-positive Bacteria Streptococcus pneumoniae Staphylococcus aureus (methicillin-susceptible isolates)
Gram-negative Bacteria Haemophilus influenzae
The BD BBL Sensi-Disc Lefamulin 20 µg (LMU-20) device is a 6 mm disc prepared by impregnating high quality absorbent paper with accurately determined amounts of Lefamulin. Discs are clearly marked on both sides with the code LMU-20. The code designates the agent Lefamulin (LMU) and the drug content (20 ug).
BD BBL Sensi-Disc Antimicrobial Susceptibility Test Discs are furnished in cartridges containing 50 discs each. The last disc in each cartridge is marked "X" and contains the drug as coded. BD BBL Sensi-Disc Antimicrobial Susceptibility Test Discs can be dispensed using a BD BBL Sensi-Disc Dispenser.
The provided document is a 510(k) Summary for the BD BBL Sensi-Disc Lefamulin 20µg (LMU-20), an antimicrobial susceptibility test disc. It details the device's intended use, performance characteristics, and comparison to a predicate device. However, it does not describe a study involving an AI/machine learning device or human readers. The acceptance criteria and performance data provided relate to the reproducibility and comparative performance of an antimicrobial susceptibility disc, which is a physical diagnostic tool for laboratory use, not a digital AI-based diagnostic system.
Therefore, many of the requested elements for describing the acceptance criteria and the study for an AI device (e.g., number of experts for ground truth, adjudication methods, MRMC studies, training set details) are not applicable to this document.
I will extract the relevant information regarding acceptance criteria and performance as presented for this specific device.
Device: BD BBL Sensi-Disc Lefamulin 20µg (LMU-20)
Device Type: Antimicrobial Susceptibility Test Disc (not an AI/machine learning device)
Purpose of Study: To demonstrate substantial equivalence to a legally marketed predicate device (HardyDisk AST Lefamulin 20µg (LMU20)) for determining antimicrobial susceptibility to Lefamulin.
Below is the information extracted and adapted based on the provided document, acknowledging that it is not for an AI device.
1. Table of Acceptance Criteria and Reported Device Performance
The document describes two main performance studies: Reproducibility and Method Comparison (Clinical and Challenge). The acceptance criteria for these are typically implied as meeting certain percentages of agreement or being within accepted ranges.
| Performance Characteristic | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| Reproducibility | >95% agreement | Between Disc Lots: 100.00% (270/270) |
| Across Readers: 98.89% (267/270) | ||
| Method Comparison | High Category Agreement (CA), low Major (MAJ) and Very Major (VMJ) errors compared to predicate device. | Overall Combined Performance (Clinical & Challenge Isolates): |
- Total Isolates Tested: 336
- Category Agreement (CA): 98.5% (331/336)
- Very Major Errors (VMJ): 4 (adjusted potential VMJ error rate is 0% due to measurement differences)
- Major Errors (MAJ): 1 |
| Specific Organisms: | | |
| Haemophilus influenzae | | Combined CA: 96.4% (108/112); VMJ: 3, MAJ: 1 |
| Staphylococcus aureus (methicillin-susceptible isolates) | | Combined CA: 100.0% (112/112); VMJ: 0, MAJ: 0 |
| Streptococcus pneumoniae | | Combined CA: 99.1% (111/112); VMJ: 1, MAJ: 0 |
2. Sample Size Used for the Test Set and Data Provenance
-
Reproducibility Study:
- Sample Size: 15 organisms (5 Haemophilus influenzae, 5 Staphylococcus aureus, 5 Streptococcus pneumoniae), tested in triplicate with two disc lots on three separate days.
- Data Points: 270 data points (15 organisms x 2 disc lots x 3 days x 3 independent readers).
- Provenance: Conducted at one external site (country of origin not specified, but the applicant and regulatory body are US-based). The study appears to be prospective in nature for generating the performance data.
-
Method Comparison Study (Clinical and Challenge):
- Clinical Isolates: 270 isolates (90 Haemophilus influenzae, 90 Staphylococcus aureus (methicillin-susceptible), and 90 Streptococcus pneumoniae).
- Challenge Isolates: 66 isolates (22 Haemophilus influenzae, 22 Staphylococcus aureus (methicillin-susceptible), and 22 Streptococcus pneumoniae).
- Total Isolates: 336 (Clinical + Challenge).
- Data Provenance: Performed at one U.S. site. The isolates likely represent a collection of retrospective or prospectively acquired clinical and challenge strains.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
This section is not applicable as the document describes a traditional antimicrobial susceptibility test disc, not an AI/machine learning device requiring expert review for image-based ground truth. The "ground truth" for this device would be the established zone diameter readings from the predicate device and the reference standard MIC (Minimum Inhibitory Concentration) method, interpreted against recognized susceptibility interpretive criteria (e.g., CLSI, FDA STIC).
- Reproducibility: Results were visually read by three independent readers. Their specific qualifications are not detailed, but generally, operators in such settings are trained laboratory personnel.
- Method Comparison: Three independent operators participated in reading of test results. Their specific qualifications are not detailed.
4. Adjudication Method for the Test Set
This is not explicitly detailed for defining the "ground truth" as it is typically understood in AI studies (e.g., in cases of disagreement among experts).
- For reproducibility, readings from three independent readers were compared against a "modal or median" zone diameter value.
- For method comparison, the "ground truth" or reference for comparison was the FDA-cleared predicate disk's results and the MIC reference method. Discrepancies (errors) were simply reported without mentioning an explicit adjudication process beyond the direct comparison.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No. This type of study (MRMC comparative effectiveness study comparing human readers with AI vs without AI assistance) is not applicable to this device. The device is a diagnostic disc, not an AI system.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable in the context of an AI algorithm. The device's performance is inherently linked to human interpretation of zone diameters. The performance stated in the table (e.g., Reproducibility, Category Agreement) reflects the device's performance when used by human operators.
7. The Type of Ground Truth Used
The "ground truth" for evaluating this device's performance is based on:
- Reference Method: Comparison against an FDA-cleared predicate device (HardyDisk AST Lefamulin 20µg (LMU20)) utilizing a standardized agar diffusion test procedure (Kirby-Bauer).
- Interpretive Criteria: Use of FDA-recognized susceptibility test interpretive criteria (e.g., from CLSI M100, FDA STIC website) which define susceptible, intermediate, and resistant categories based on zone diameters or MICs.
- MIC Results: Where errors occurred, the document mentions that potential VMJ errors were compared to "historical MIC results," implying an underlying MIC reference method for establishing the true susceptibility category.
8. The Sample Size for the Training Set
Not applicable. This is a physical diagnostic disc, not an AI model that requires a training set.
9. How the Ground Truth for the Training Set Was Established
Not applicable. As above, there is no AI training set for this type of device.
§ 866.1620 Antimicrobial susceptibility test disc.
(a)
Identification. An antimicrobial susceptibility test disc is a device that consists of antimicrobic-impregnated paper discs used to measure by a disc-agar diffusion technique or a disc-broth elution technique the in vitro susceptibility of most clinically important bacterial pathogens to antimicrobial agents. In the disc-agar diffusion technique, bacterial susceptibility is ascertained by directly measuring the magnitude of a zone of bacterial inhibition around the disc on an agar surface. The disc-broth elution technique is associated with an automated rapid susceptibility test system and employs a fluid medium in which susceptibility is ascertained by photometrically measuring changes in bacterial growth resulting when antimicrobial material is eluted from the disc into the fluid medium. Test results are used to determine the antimicrobial agent of choice in the treatment of bacterial diseases.(b)
Classification. Class II (performance standards).