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Abuscreen ONLINE for Phencyclidine is an in vitro diagnostic test for the qualitative and semiquantitative detection of phencyclidine and its metabolites in human urine on the Hitachi 917 analyzer at a cutoff concentration of 25 ng/mL. Semiquantitative test results may be obtained that permit laboratories to assess assay performance as part of a quality control program. Measurements obtained by this device are used in the diagnosis of phencyclidine use or abuse.

Abuscreen ONLINE for Phencyclidine is an in vitro diagnostic test for the qualitative and semiquantitative detection of phencyclidine and its metabolites in human urine on automated clinical chemistry analyzers at a cutoff concentration of 25 ng/mL. Semiquantitative test results may be obtained that permit laboratories to assess assay performance as part of a quality control program. Measurements obtained by this device are used in the diagnosis of phencyclidine use or abuse.

The proposed Abuscreen ONLINE Phencyclidine test kit is specifically intended for use on the Hitachi 917 Analyzer and future similar analyzer models. It was adapted from the currently marketed Abuscreen ONLINE Phencyclidine test kit. The labeling and packaging have been changed for use on the Hitachi 917 Analyzer as well as an addition of a surfactant to the diluent. This modified test kit is not a replacement to the currently marketed kit.

The Hitachi 917 Analyzer System is a fully automatic, computer-controlled system for clinical chemistry. It was conceived for both quantitative and qualitative in vitro determination using a large variety of tests for analysis, e.g. in serum and urine. Integrated in the system is an ion-selective unit for determination of electrolytes. The throughput per hour is 800 tests for clinical chemistry (1200 with electrolytes). The system consists of the analyzer which performs all functions required for fully automatic sample and testprocessing. Beginning with the automatic recording of patient samples - provided that they are supplied in barcode-labeled vessels - up to the photometric measurement and results transmission to the computer unit.

1. Table of Acceptance Criteria and Reported Device Performance

95% positive at 31.25 ng/mL | >95% negative at 18.75 ng/mL
95% positive at 31.25 ng/mL | >95% negative at 20 ng/mL
95% positive at 30 ng/mL |
| Precision (Within Run) - OD (CV%) | Not explicitly stated as acceptance criteria, but reported values are compared to predicate. | 12.5 ng/mL: 2.9%
18.75 ng/mL: 3.3%
25.0 ng/mL: 1.8%
31.25 ng/mL: 2.0%
37.5 ng/mL: 1.2% | Not provided in terms of individual CVs for predicate, only qualitative stated. |
| Precision (Day-to-Day) - OD (CV%) | Not explicitly stated as acceptance criteria, but reported values are compared to predicate. | 12.5 ng/mL: 3.3%
18.75 ng/mL: 4.8%
25.0 ng/mL: 3.5%
31.25 ng/mL: 3.3%
37.5 ng/mL: 3.1% | Not provided in terms of individual CVs for predicate, only qualitative stated. |
| Precision (Within Run) - Quantitative (CV%) | Not explicitly stated as acceptance criteria, but reported values are compared to predicate. | 12.5 ng/mL: 6.2%
18.75 ng/mL: 4.3%
25.0 ng/mL: 2.0%
31.25 ng/mL: 2.1%
37.5 ng/mL: 1.9% | 12.5 ng/mL: 7%
18.75 ng/mL: 6%
25.0 ng/mL: 3%
31.25 ng/mL: 3% |
| Precision (Day-to-Day) - Quantitative (CV%) | Not explicitly stated as acceptance criteria, but reported values are compared to predicate. | 12.5 ng/mL: 8.6%
18.75 ng/mL: 6.6%
25.0 ng/mL: 5.0%
31.25 ng/mL: 4.0%
37.5 ng/mL: 3.4% | 12.5 ng/mL: 10%
18.75 ng/mL: 5%
25.0 ng/mL: 3%
31.25 ng/mL: 3% |
| Accuracy (25 ng/mL Cutoff) | Not explicitly stated as a numerical acceptance criterion, but demonstrated by agreement with confirmed samples. | N=50 Confirmed Pos.: 50 Pos., 0 Neg.
N=14 (25% above cutoff): 14 Pos., 0 Neg.
N=14 (25% below cutoff): 0 Pos., 14 Neg. | N=75 Confirmed Pos.: 75 Pos., 0 Neg. |
| Limit of Detection | Comparability to predicate device. | 0.6 ng/mL | 6 ng/mL (clinical sensitivity) |

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

• Test Set Sample Size:
  • Precision (Qualitative & Quantitative): The document reports "Mean (OD)" and "Mean (ng/mL)" values for various concentrations (12.5, 18.75, 25.0, 31.25, 37.5 ng/mL) under "Within Run" and "Day-to-Day" conditions. While the exact number of replicates per run/day isn't explicitly stated, the CV% values indicate multiple measurements were taken for each concentration.
  • Accuracy:
    • N = 50 confirmed positive samples.
    • N = 14 samples diluted within 25% above cutoff concentration.
    • N = 14 samples diluted within 25% below cutoff concentration.
• Data Provenance: The document does not specify the country of origin of the data or whether the study was retrospective or prospective. It presents the data as performance characteristics obtained from clinical and nonclinical studies.

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

The document does not provide information on the number of experts used or their qualifications for establishing ground truth. The "Confirmed Pos." in the Accuracy section implies a confirmatory method was used, but the details of who performed this confirmation and their expertise are not given.

4. Adjudication Method for the Test Set

The document does not describe any specific adjudication method (e.g., 2+1, 3+1, none) for the test set.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No MRMC comparative effectiveness study is mentioned. This device is an in vitro diagnostic test for chemical analysis, not an imaging device requiring human reader interpretation in the same way.

6. Standalone Performance (Algorithm Only without Human-in-the-Loop Performance)

Yes, the study describes the standalone performance of the Abuscreen ONLINE Phencyclidine for Hitachi 917 device. The precision and accuracy data reflect the performance of the automated system operating independently. The "semisuantitative test results may be obtained that permit laboratories to assess assay performance as part of a quality control program," indicating the automated nature of the results.

7. Type of Ground Truth Used

The ground truth for the "Accuracy" section was established by "Confirmed Pos." meaning it was likely confirmed by an independent, more definitive analytical method, although the specific method (e.g., GC/MS) is not explicitly named. It is based on analytical confirmation rather than pathology or outcome data.

8. Sample Size for the Training Set

The document does not explicitly mention a "training set" or its sample size. This type of device (enzyme immunoassay) is typically characterized and validated rather than trained in the machine learning sense. The data presented are for evaluating the performance of the developed assay.

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

As no training set is described for this type of device, the method for establishing ground truth for a training set is not applicable or provided. The "ground truth" in this context refers to accurately known concentrations of phencyclidine in samples used for validation and verification, which would be established through highly accurate analytical methods.

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