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Antimicrobial Susceptibility Test Discs are used for semi-quantitative in vitro susceptibility testing by standardized agar diffusion test procedures. Sparfloxacin Sensi-Discs® are intended for use in determining the susceptibility to Sparfloxacin of a wide range of bacteria, including Staphylococcus aureus, Streptococcus pneumoniae (penicillin-susceptible strains), Enterobacter cloacae, Haemophilus influenzae, Haemophilus parainfluenzae, Klebsiella pneumoniae, Moraxella catarrhalis, Chlamydia pneumoniae, and Mycoplasma pneumoniae. Zone sizes used for interpretation of tests, including control organism limits, were determined by the antimicrobic manufacturer, Rhone Poulenc Rorer Pharmaceuticals, Inc., and received FDA approval under NDA No. 20-677.

Use of BBL® Sparfloxacin Sensi-Discs® for in vitro agar diffusion susceptibility testing is indicated when there is a need to determine the susceptibility of bacteria to Sparfloxacin. Sparfloxacin has been shown to be active against most strains of microorganisms listed below, both in vitro and in clinical infections, as described in the Rhone Poulenc Rorer Pharmaceuticals, Inc., package insert for this antimicrobic.

Sparfloxacin Susceptibility Test Discs are prepared by impregnating high quality paper with accurately determined amounts of Sparfloxacin supplied by the manufacturer, Rhone Poulenc Rorer Pharmaceuticals, Inc., Collegeville, Pennsylvania. Each Sparfloxacin disc is clearly marked on both sides with the agent and content. Sparfloxacin discs are furnished in cartridges of 50 discs each. Sparfloxacin cartridges are packed as either a single cartridge in a single box, or in a package containing ten cartridges.

Agar diffusion methods employing dried filter paper discs impregnated with specific concentrations of antimicrobial agents were developed in the 1940's. In order to eliminate or minimize variability in the testing, Bauer et al. developed a standardized procedure in which Mueller Hinton Agar was selected as the test medium.

Various regulatory agencies and standards-writing organizations subsequently published standardized reference procedures based on the Bauer-Kirby method. Among the earliest and most widely accepted of these standardized procedures were those published by the U.S. Food and Drug Administration (FDA) and the World Health Organization (WHO). The procedure was adopted as a consensus standard by the National Committee for Clinical Laboratory Standards (NCCLS) and is periodically updated. The latest NCCLS documents are M2-A5 (12/93) and M100-S6 (12/95).

Discs containing a wide variety of antimicrobial agents are applied to the surface of Mueller Hinton Agar plates [or Haemophilus Test Medium Agar for H. influenzae or Mueller Hinton Agar with 5% Sheep Blood for S. pneumoniae] inoculated with pure cultures of clinical isolates. Following incubation, the plates are examined and the zones of inhibition surrounding the discs are measured and compared with established zone size ranges for individual antimicrobial agents in order to determine the agent(s) most suitable for use in antimicrobial therapy. The determination as to whether the organism in question is susceptible (S), intermediate (I), or resistant (R) to an antimicrobial agent is made by comparing zone sizes to those found in the respective organism tables of National Committee for Clinical Laboratory Standards (NCCLS) Document M2-A5 ("Performance Standards for Antimicrobial Disk Susceptibility tests - Fifth Edition, Approved Standard", 12/93) and of NCCLS Document M100-S6 ("Performance Standards for Antimicrobial Susceptibility Testing", Sixth Informational Supplement, 12/95).

This document describes the BBL® Sparfloxacin Sensi-Discs® for antimicrobial susceptibility testing. The data provided focuses on the clinical effectiveness of Sparfloxacin itself, rather than the performance of the Sensi-Discs® as a diagnostic device. The Sensi-Discs® are intended to determine the susceptibility of bacteria to Sparfloxacin using standardized agar diffusion tests.

Here's an analysis of the provided information regarding acceptance criteria and supporting studies, contextualized for the device (Sparfloxacin Sensi-Discs®) where possible, and acknowledging that much of the performance data relates to the drug Sparfloxacin:

1. Table of Acceptance Criteria and Reported Device Performance

For the Sparfloxacin Sensi-Discs®, the acceptance criteria are not explicitly detailed in terms of a device-specific performance study with metrics like accuracy, sensitivity, or specificity against a reference method. Instead, the performance is tied to zone size interpretation and quality control ranges provided by the drug manufacturer (Rhone Poulenc Rorer Pharmaceuticals) and standardized by NCCLS.

The primary study mentioned directly concerning the device's acceptable performance is the adherence to the National Committee for Clinical Laboratory Standards (NCCLS) documents M2-A5 and M100-S6. These documents provide the standardized procedures for antimicrobial disk susceptibility tests, including zone size interpretation and quality control limits. The device, by its nature as an "Antimicrobial Susceptibility Test Disc," is designed to be used within these established guidelines.

2. Sample Size Used for the Test Set and Data Provenance

The document does not detail a specific "test set" for the Sparfloxacin Sensi-Discs® themselves, as the approval relies on adherence to established NCCLS standards and the clinical data for the drug Sparfloxacin.

• For the drug Sparfloxacin clinical studies (Community-Acquired Pneumonia and Acute Bacterial Exacerbations of Chronic Bronchitis):
  • Community-Acquired Pneumonia:
    • Sparfloxacin: n=22 to 41 per organism (total = 199 unique pathogen-patient cases reported across listed organisms)
    • Erythromycin: n=4 to 15 per organism (total = 49)
    • Cefaclor: n=5 to 24 per organism (total = 124)
  • Acute Bacterial Exacerbations of Chronic Bronchitis:
    • Sparfloxacin: n=13 to 109 per organism (total = 269 unique pathogen-patient cases)
    • Ofloxacin: n=14 to 95 per organism (total = 277)
  • Data Provenance: The clinical studies were conducted "in the United States." The data is prospective, as these are clinical trials comparing drug efficacy.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

This information is not provided for the Sensi-Discs® themselves or for the clinical studies of the Sparfloxacin drug. For diagnostic device performance, establishing ground truth often involves reference methods performed by qualified laboratory personnel. For the Sensi-Discs®, the "ground truth" for interpretation is implicitly derived from the established NCCLS zone diameter breakpoints, which are scientifically determined standards rather than expert consensus on individual cases.

4. Adjudication Method for the Test Set

This information is not provided. For antimicrobial susceptibility testing, adjudication is typically not performed in the same way as in image-based diagnostic studies. The results are quantitative measurements (zone diameters) interpreted against predefined breakpoints. Clinical success in drug trials is usually determined by clinical outcomes and microbiological eradication, not an adjudication process by experts on individual treatment responses in the context of the device's performance.

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 MRMC study was done, as this document predates the widespread application of AI in diagnostics and the device (antimicrobial susceptibility disc) is not an AI-powered diagnostic tool. The "readers" in this context are laboratory technicians measuring zone diameters, and their performance is standardized and controlled by NCCLS guidelines and quality control measures, not by AI assistance.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

This is not applicable. The device is a physical disc used in a laboratory procedure requiring human measurement and interpretation. There is no "algorithm only" component.

7. The Type of Ground Truth Used

• For the Sparfloxacin Sensi-Discs® (as a diagnostic device): The ground truth is expert consensus-based standards and recognized reference methods. The interpretive zone sizes and quality control ranges are established by organizations like NCCLS (National Committee for Clinical Laboratory Standards) through a consensus process involving experts in microbiology and infectious diseases, validated against clinical outcomes and MIC data. The "gold standard" for determining MICs (Minimum Inhibitory Concentrations) is typically broth microdilution or agar dilution as per CLSI (formerly NCCLS) guidelines. The disc diffusion method is then correlated to these MIC values.
• For the Sparfloxacin drug clinical trials: The ground truth for treatment effectiveness was clinical success (e.g., patient recovery, resolution of symptoms) and pathogen eradication (microbiological cure) demonstrated through follow-up cultures.

8. The Sample Size for the Training Set

The document does not describe a "training set" in the context of machine learning or AI. For the Sparfloxacin Sensi-Discs®, the "training data" for establishing breakpoints and QC ranges would implicitly be the extensive historical data and research collected by the NCCLS and drug manufacturers to correlate MICs with zone sizes and clinical outcomes. This would have involved numerous isolates and experiments over time, but is not quantified as a single "training set size" in this document.

9. How the Ground Truth for the Training Set Was Established

As discussed above, the concept of a "training set" with ground truth in the AI sense does not apply directly here. For antimicrobial susceptibility testing, the "ground truth" for establishing interpretive breakpoints and quality control ranges (which guide the use of the device) is established through:

• Correlation studies: Comparing disc diffusion zone diameters with MIC values obtained from reference methods (e.g., broth microdilution) for a large number of bacterial isolates.
• Clinical outcome data: Analyzing the clinical efficacy (patient response) and microbiological eradication rates of the drug in patients infected with organisms having specific MICs and corresponding disc diffusion zone diameters. This helps define the clinical relevance of "susceptible," "intermediate," and "resistant" categories.
• Expert consensus: Committees like NCCLS (now CLSI) using all available scientific evidence, including in vitro data and clinical trial results, to determine and periodically update the breakpoints.

In essence, the Sparfloxacin Sensi-Discs® rely on well-established and scientifically validated methodologies rather than new, device-specific performance studies against a novel ground truth. The "study that proves the device meets the acceptance criteria" is primarily the adherence to and validation against the NCCLS standards and the clinical data for the drug itself provided by Rhone Poulenc Rorer Pharmaceuticals.

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