(90 days)
BD BACTECTM Standard Anaerobic/F culture vials (prereduced enriched Soybean-Casein Digest broth with CO2) are for anaerobic blood cultures. Principal use is with the BD BACTEC fluorescent series instruments for the qualitative culture and recovery of anaerobic microorganisms from blood.
The sample to be tested is inoculated into one or more vials which are inserted into the BD BACTEC fluorescent series instrument for incubation and periodic reading. Each vial contains a chemical sensor which can detect increases in CO2 produced by the growth of microorganisms. The sensor is monitored by the instrument every ten minutes for an increase in its fluorescence, which is proportional to the amount of CO2 present. A positive reading indicates the presumptive presence of viable microorganisms in the vial. Detection is limited to microorganisms that will grow in a particular type of medium.
The provided document describes the BD BACTEC™ Standard Anaerobic/F Culture Vials Soybean-Casein Digest Broth in a Plastic Vial (modified device) and its substantial equivalence to the predicate device (glass vial). The studies performed are analytical and focus on the performance of the culture medium and vial characteristics.
Here's a breakdown of the requested information based on the document:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state quantitative "acceptance criteria" for each test. Instead, it indicates that the modified device should perform "equivalently" or show "no relevant difference" compared to the predicate device. For the purpose of this table, "Acceptance Criteria" are inferred from the study conclusions.
| Performance Metric | Acceptance Criteria (Inferred) | Reported Device Performance |
|---|---|---|
| Instrument Time to Detection | No relevant difference from the predicate device | Wilcoxon estimated median TTD difference for 443 positive paired sets is -0.500 hours (30 minutes), favoring the modified device. Conclusion: Effect of differences on TTD was minimal; modified device performs equivalently to the predicate device. |
| Percent Recovery | Recovery equivalent between modified and predicate devices | 528 paired sets evaluated; 504 paired sets positive in both at 10-100 CFU inoculum. McNemar p-value could not be calculated as neither device showed exclusive detection. Conclusion: Recovery was equivalent. |
| Microbial Detection Limit | No statistically significant difference in recovery compared to the predicate device | 312 paired sets inoculated: 191 grew in both, 36 in predicate only, 39 in modified only, 46 in neither. McNemar chi-square analysis: p=0.8174. Conclusion: No statistically significant difference in recovery. |
| False Positive Rate | No false positive bottles for the modified device | 240 paired sets (40 from each of 3 lots) inoculated with fresh human blood at varying levels. All expected to be instrument-negative. Conclusion: No false positive bottles observed for the modified device with blood volumes (2, 4, 6, 8, and 10mL). |
| False Negative Rate | No statistically significant difference in recovery compared to the predicate device | 70 paired sets end of protocol negative evaluated for false negative rate. 36 modified device only instrument negatives, 39 predicate device only instrument negatives. 1 false negative observed in the predicate device. McNemar chi-square analysis: p=1.00. Conclusion: No statistically significant difference in recovery. |
| Reproducibility (Lot-to-Lot) | No relevant difference in time to detection across lots | No relevant difference in time to detection observed between lot comparisons. |
2. Sample Size Used for the Test Set and Data Provenance
The document describes analytical studies. The "test set" in this context refers to the samples used in these analytical performance studies.
- Instrument Time to Detection: 443 paired sets
- Percent Recovery: 528 paired sets
- Microbial Detection Limit: 312 paired sets
- False Positive Rate: 240 paired sets (40 from each of 3 lots)
- False Negative Rate: 70 paired sets
Data Provenance: The document does not explicitly state the country of origin or whether the data was retrospective or prospective. Given the nature of these analytical studies (e.g., inoculation with specific CFU levels), they are inherently prospective and controlled laboratory experiments. The origin of the human blood used for the false positive rate study is not specified beyond "fresh human blood."
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Those Experts
This information is not provided in the document. The studies are analytical performance comparisons of a microbial growth medium, not diagnostic accuracy studies that rely on expert interpretation of results. The "ground truth" for these studies is typically defined by microbial culture techniques (e.g., presence/absence of growth, colony counts) rather than expert consensus on images or clinical classifications.
4. Adjudication Method for the Test Set
This information is not applicable/provided. Adjudication methods (like 2+1, 3+1) are typically used in clinical studies where multiple human readers interpret data, and discrepancies need to be resolved. These analytical studies focus on the objective measurement of microbial growth and detection by the instrument.
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
This information is not applicable. The device (BD BACTEC™ Standard Anaerobic/F Culture Vials) is a culture medium used with an automated instrument (BD BACTEC fluorescent series instruments) for detecting microbial growth in blood. It is not an AI-powered diagnostic device or an imaging device that involves human readers interpreting results with or without AI assistance. Therefore, an MRMC comparative effectiveness study involving human readers and AI is outside the scope of this device.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
This information is not applicable in the context of an "algorithm only" device. The device itself is a culture vial (medium) that is used with an instrument. The instrument's algorithms detect growth. The studies evaluate the performance of the vial and medium in conjunction with the instrument, not an isolated algorithm. The "standalone" performance is essentially what the analytical studies describe – the ability of the combined system to detect growth.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
The ground truth for these analytical studies is based on microbiological culture and laboratory methods.
- Presence/absence of microbial growth: Confirmed by standard microbiological techniques (e.g., subculture to agar plates, colony identification).
- Time to detection (TTD): Objectively measured by the BACTEC instrument.
- Colony-forming units (CFU): Used to prepare inoculum levels for certain studies.
8. The Sample Size for the Training Set
This information is not provided and is not applicable in the context presented. The document describes an analytical performance comparison study for a modified device against a predicate device. It does not mention any machine learning or AI components that would require a distinct "training set" in the conventional sense. The instrument's algorithms are assumed to be pre-existing and validated.
9. How the Ground Truth for the Training Set Was Established
This information is not provided and is not applicable for the reasons stated in point 8.
§ 866.2560 Microbial growth monitor.
(a)
Identification. A microbial growth monitor is a device intended for medical purposes that measures the concentration of bacteria suspended in a liquid medium by measuring changes in light scattering properties, optical density, electrical impedance, or by making direct bacterial counts. The device aids in the diagnosis of disease caused by pathogenic microorganisms.(b)
Classification. Class I. With the exception of automated blood culturing system devices that are used in testing for bacteria, fungi, and other microorganisms in blood and other normally sterile body fluids, this device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter.