(379 days)
The Actim PROM test is a visually interpreted, qualitative immunoassay rapid test for the detection of amniotic fluid in cervicovaginal secretions during pregnancy. The Actim PROM test detects IGFBP-1, a major protein in amniotic fluid and a marker of the presence of amniotic fluid in a vaginal sample. The test is intended for prescription use in point of care and clinical laboratory settings to help diagnose the rupture of fetal membranes (ROM) in pregnant women ≥29 weeks gestation who present with signs, symptoms or complaints suggestive of ROM.
The Actim PROM test is a rapid test to aid in diagnosis of premature rupture of fetal membranes in pregnant women who present with signs, symptoms or complaints suggestive of RQM. The test is based on lateral flow immunoassay. It utilizes two monoclonal antibodies to human IGFBP-1. One of the two antibodies is bound to blue latex particles (detecting antibody). The other antibody is immobilized as a test line on the membrane (catching antibody). The test strip (dipstick) is composed of the sample/conjugate pad, the membrane with test and control lines, and the absorbent pad assembled between plastic films. The upper film contains a test window. When the sample area of the dipstick is placed in an extracted sample, the dipstick absorbs liquid, which starts to flow up the dipstick. If the sample contains IGFBP-1 it binds to the antibody labeled with latex particles. The particles are carried by the liquid flow, and if IGFBP-1 is bound to them, they bind to the catching antibody. A blue line (test line) will appear in the result area if the concentration of IGFBP-1 in the sample exceeds the detection limit of the test. A second blue line, the control line, confirms correct operator performance of the test.
The provided text describes a 510(k) submission for the Actim PROM test, which is a rapid diagnostic test to aid in the diagnosis of premature rupture of fetal membranes (PROM).
Here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
The submission does not explicitly state pre-defined acceptance criteria in terms of specific sensitivity and specificity thresholds. However, the clinical study's results are presented, and the FDA's clearance implies that these results were deemed acceptable for the expanded intended use. For the purpose of this analysis, we can infer that the reported performance in Table 1 represents the "met" criteria.
| Metric (for ≥ 29 weeks Gestational Age) | Acceptance Criteria (Inferred) | Reported Device Performance (Without Speculum) | Reported Device Performance (With Speculum) |
|---|---|---|---|
| Sensitivity | High (to diagnose ROM) | 90.1% (95% CI: 83.1-94.4%) | 95.5% (95% CI: 89.8-98.0%) |
| Specificity | High (to rule out ROM) | 91.0% (95% CI: 84.2-95.0%) | 86.4% (95% CI: 78.7-91.6%) |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: 222 pregnant women for the overall study (≥ 29 weeks gestational age).
- For samples collected without a speculum: 222 (used in the overall analysis).
- For samples collected with a speculum: 220 (2 invalid results excluded).
- Data Provenance:
- Country of Origin: Multi-center study conducted at six US clinical sites.
- Retrospective or Prospective: Prospective clinical study.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of those Experts
The text does not specify the number of experts who established the ground truth. It states that the ground truth was determined by "clinical diagnosis as determined by the conventional clinical criteria identified above." These criteria include:
- Amniotic fluid seen leaking from the cervical os upon diagnostic speculum examination.
- Two of the three following clinical signs being positive: visual pooling of fluid in the posterior fornix, positive nitrazine test, or microscopic evidence of ferning.
The qualifications of the individuals making this clinical diagnosis (e.g., attending physicians, gynecologists, obstetricians) are not explicitly mentioned, but it is implied to be experienced medical professionals involved in patient care.
4. Adjudication Method for the Test Set
The adjudication method for establishing the ground truth was based on a combination of clinical observations and tests:
- Primary criterion: Amniotic fluid seen leaking from the cervical os upon diagnostic speculum examination.
- Secondary criteria (if the primary was not met): Fulfillment of at least two out of three conventional clinical signs (visual pooling, positive nitrazine test, or microscopic ferning).
This effectively acts as a consensus/hierarchical adjudication for clinical diagnosis, where direct observation is definitive, and a combination of other signs confirm in its absence.
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, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not conducted, nor is the device an AI. The Actim PROM test is a visually interpreted, qualitative immunoassay rapid test. The study compared the device's performance against conventional clinical diagnosis, not against human readers with or without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
The Actim PROM test is a standalone test in the sense that its result (the appearance of a blue line) is interpreted visually by a human operator. However, it's not an "algorithm only" device; it's a diagnostic kit. The study evaluates the performance of this standalone kit. The stated intended use is "visually interpreted." The "standalone" performance shown in the tables is the performance of the device without further human interpretation beyond reading the test line.
7. The Type of Ground Truth Used
The ground truth used in the clinical study was expert clinical diagnosis based on a set of conventional clinical criteria for PROM. These criteria included:
- Amniotic fluid seen leaking from the cervical os upon diagnostic speculum examination.
- Two of the three following clinical signs being positive: visual pooling of fluid in the posterior fornix, positive nitrazine test, or microscopic evidence of ferning.
8. The Sample Size for the Training Set
The text does not explicitly mention a separate "training set" for the Actim PROM device itself, as it is a lateral flow immunoassay device rather than a machine learning algorithm that requires a training phase. The clinical study described is a performance validation study on a test set.
9. How the Ground Truth for the Training Set Was Established
As there's no mention of a traditional "training set" in the context of an algorithm, this question is not directly applicable. If an older version of the device was "trained" or developed, the information is not provided in this specific submission summary. The current submission focuses on expanding the intended use for an existing device.
§ 862.1550 Urinary pH (nonquantitative) test system.
(a)
Identification. A urinary pH (nonquantitative) test system is a device intended to estimate the pH of urine. Estimations of pH are used to evaluate the acidity or alkalinity of urine as it relates to numerous renal and metabolic disorders and in the monitoring of patients with certain diets.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 862.9.