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The Q-Pad Kit is an in vitro diagnostic specimen collection and storage device intended for the collection of menstrual blood samples by individuals 18 years and older for subsequent analysis by an assay validated for use with the Q-Pad menstrual pad.

The Q-Pad A1c Test is an in vitro diagnostic device for the quantitative measurement of Hemoglobin A1C using menstrual whole blood collected onto filter paper using the Q-Pad A1c Test is for the measurement of HbA I c on whole menstrual blood which will be self-collected by lay users at home and shipped to the laboratory by mail. Measurements obtained through this method can be used for monitoring the long-term control of blood sugar (glucose) in women with diabetes.

This test is not to be used to diagnose or screen for diabetes.

Device Description

The Q-Pad Test System consists of the Q-Pad Kit and the Q-Pad A1c Test. The Q-Pad Kit is an in vitro diagnostic specimen collection and storage device intended for the collection of menstrual blood samples. The Q-Pad A1c Test is an in vitro diagnostic device for the quantitative measurement of Hemoglobin A1C using menstrual whole blood collected onto filter paper using the Q-Pad Kit. The Q-Pad menstrual pad (also referred to as "Q-Pad") is a modified menstrual pad which looks, feels, and is used like a normal menstrual pad. The Q-Pad has an embedded blood collection strip (Q-Strip) which can easily be removed and shipped for analysis at a laboratory. Instructions for use and results are presented in a HIPAA compliant mobile application.

AI/ML Overview

The provided text describes the acceptance criteria and study that proves the Q-Pad Test System meets the acceptance criteria. It focuses on the performance of a medical device designed for measuring Hemoglobin A1c (HbA1c) from menstrual blood samples.

Here's the breakdown of the information requested, based on the provided text:

Acceptance Criteria and Device Performance

A table summarizing the acceptance criteria and the reported device performance for several key studies:

Acceptance Criteria Category	Specific Acceptance Criteria	Reported Device Performance
Precision (Venous Blood)	Overall imprecision no greater than 2.56% (acceptance criterion ≤ 4%)	Low A1c: Total %CV = 1.99% Elevated A1c: Total %CV = 1.82% High A1c: Total %CV = 1.91% Very High A1c: Total %CV = 2.44% (All met the ≤ 4% criterion, and the overall maximum was 2.56%)
Precision (Menstrual Blood)	Overall imprecision no greater than 3.59% (acceptance criterion ≤ 4%)	Low A1c: Total %CV = 3.59% Elevated A1c: Total %CV = 2.15% High A1c: Total %CV = 1.60% (All met the ≤ 4% criterion, and the overall maximum was 3.59%)
Intra-strip Precision	Bias < 10% between punches 2 and 3 compared to the first punch; Average imprecision < 3.9% between punches.	Maximum bias of 4.90% recorded. Maximum CV between punches of 2.92%. Low A1c: %CV (95% CI) = 1.15 (0.00, 2.36) Mid A1c: %CV (95% CI) = 1.75 (0.00, 4.26) High A1c: %CV (95% CI) = 1.08 (0.00, 2.30) (Met criteria)
Inter-strip Precision	Bias < 10%; Average imprecision < 3.9% between Q-Strip samples.	Maximum bias of 3.92%. Maximum %CV of 2.72%. Low A1c: %CV (95% CI) = 0.44 (0.00, 1.22) Mid A1c: %CV (95% CI) = 2.59 (2.06, 3.11) High A1c: %CV (95% CI) = 0.44 (0.00, 1.41) (Met criteria)
Linearity (Menstrual Blood)	Based on linear regression and polynomial fit analysis; to support a claimed measuring range of 4.0% to 15.0% HbA1c.	Polynomial fit analysis verified linearity. 2nd and 3rd order polynomials were statistically equivalent to zero, making the best fit polynomial a linear function. Linearity established from 4.4% to 14.5% HbA1c. This range supports the claimed measuring range (AMR) of 4.0% to 15.0%.
Interfering Substances	Significant interference defined as >10% bias between a spiked and an unspiked sample.	No incidence of interference detected with any of the 40 tested exogenous and endogenous substances (at four HbA1c levels for each substance). Exception: For Hemoglobin variant F, with variant concentration >10%, interference was observed. This resulted in a limitation in the product package insert.
Specimen Stability with Simulated Shipping	<10% deviation from T0 for measured values at various time points (Day-6, Day-10, Day-14, Day-28, Day-31). No significant drift.	All measured values were within the acceptable range (<10% deviation). No significant drift observed (95% CI of regression lines did not cross TEa bounds). Claimed sample stability period of 28 days.
Shelf-Life (Accelerated)	All measured values within acceptable range (<10% bias from reference).	All measured values were within the acceptable range. Supports 3-year shelf life. Real-time study running concurrently.
Open Pouch Shelf-Life	All measured values within acceptable range (<10% bias from reference).	All measured values were within the acceptable range. Mitigates risk of inaccurate results from opened but unused kits.
Reference Interval	Verification of equivalence to NACB recommended HbA1c reference range of 4.0% to 6.0% HbA1c.	All participant results were inside the expected reference range. Mean = 5.17% HbA1c, Central 95% interval = 4.54% to 5.77%. Standardized range found to be equivalent to the NACB recommended range. Claimed reference interval for healthy individuals: 4.0% - 6.0%.
Method Comparison (Clinical Study)	Slope between 0.93 and 1.07 with CI including 1; Intercept between -0.7 and 0.7 with CI including 0; R² of >0.95. No samples outside of total allowable error of 6%.	Slope = 1.003 (95% CI 0.987, 1.020); Intercept = -0.0461 (95% CI -0.170, 0.0669); R² = 0.99. All acceptance criteria met. Demonstrated clinical performance equivalent to the reference method (venous blood). 99% of participants successfully collected a sample. No samples outside of the stated total allowable error of 6%.
Usability Study	Users able to follow Instructions for Use (IFU) and successfully collect a sample leading to a valid HbA1c result.	40 naive participants (self-reported diabetics) were able to follow IFU. 97.5% successfully collected a sample that led to a valid HbA1c result. (Met criteria)
Elution Stability	<10% bias between measured time point and initial measurement immediately after extraction for up to 4 hours.	For all time points and HbA1c levels, the maximum bias was 3.37%. Verified stability of eluted sample for up to 4 hours.

Study Details

Here's a breakdown of the specific details regarding the studies:

2. Sample size used for the test set and the data provenance:

Sample Matrix Equivalency Study: 40 paired (venous and menstrual blood) samples. Data provenance not explicitly stated, but implies clinical samples.
Precision (Venous Blood) Study: 320 samples (80 per HbA1c level from 4 participants). Implies lab-controlled testing.
Precision (Menstrual Blood) Study: 20 samples per HbA1c level (from 3 participants). Implies self-collected samples from lay users.
Intra-strip Precision Study: Samples from 9 participants.
Inter-strip Precision Study: Samples from 9 participants.
Linearity (Menstrual Blood) Study: Not explicitly stated, but involved serially diluted samples to create a nine-member known interval menstrual blood panel. Lab-based.
Interfering Substances Study: 40 substances evaluated, each tested at four HbA1c levels. Lab-based.
Hemoglobin Variants Study: Hemoglobin variants C, -D, -E, -F, and -S from an NGSP reference laboratory, tested at three HbA1c levels each. Lab-based.
Specimen Stability with Simulated Shipping Study: Samples from 8 participants. Implies self-collected.
Reference Interval Study: 128 healthy participants. Implies clinical samples.
Method Comparison (Clinical Validation) Study: 396 specimens from 198 participants.
- Data Provenance: Not explicitly stated regarding country of origin, but implies multi-site or broader collection for the clinical validation study as samples were collected via "Instructions for Use (IFU) and were returned to the laboratory using USPS First-class Return Service." This suggests a US-based, prospective, at-home collection study.
Usability Study: 40 naive participants (self-reported diabetics). Implies US-based, prospective, at-home collection.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

The document does not specify the number or qualifications of experts used to establish ground truth.
For HbA1c measurements, the "ground truth" or reference method is typically the results from a highly accurate, standardized laboratory analyzer using a reference method (e.g., Beckman Coulter AU480 for the subject device, Beckman Coulter AU640e for the predicate) and traceable to the National Glycohemoglobin Standardization Program (NGSP) and IFCC reference calibrators. The Method Comparison study used a "venous blood reference method" performed by a phlebotomist and analyzed at a CLIA-certified clinical laboratory (Qvin Labs) on the Beckman Coulter Hemoglobin A1c Test on an AU480 chemistry analyzer.

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:

The document does not describe an adjudication method for the test set data. For quantitative measurements like HbA1c, adjudication by multiple readers is generally not applicable in the same way it would be for qualitative assessments (e.g., image interpretation). Instead, the reference method's accuracy and traceability are key.

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 device is an in vitro diagnostic for quantitative measurement, not an AI-assisted diagnostic imaging or qualitative interpretation device. Therefore, a multi-reader multi-case (MRMC) comparative effectiveness study comparing human readers with and without AI assistance is not applicable and was not performed. The focus is on the accuracy and precision of the device's measurement compared to a reference method.

6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:

The device performs a quantitative measurement of HbA1c. The "standalone" performance here refers to the device itself (the Q-Pad Test System, which includes the collection kit and the A1c test performed in a lab) providing a numeric result. All the performance studies (precision, linearity, interference, stability, method comparison) are essentially standalone performance evaluations of the device system. Human involvement is primarily in sample collection, not in interpreting the final quantitative output.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

The primary ground truth for the HbA1c measurements was reference methodology using a venous blood sample analyzed by an FDA-cleared laboratory reagent and analysis system (Beckman Coulter AU480 clinical chemistry device), traceable to NGSP and IFCC reference calibrators.
For the Interfering Substances and Hemoglobin Variants studies, reference values or known concentrations were used.
For the Reference Interval study, samples from healthy participants were used to establish a range and compare to national recommendations (NACB).

8. The sample size for the training set:

The document describes performance studies for a medical device (Q-Pad Test System) which is an in vitro diagnostic for measuring HbA1c. This device does not appear to rely on a "training set" in the context of machine learning. The studies described are validation studies for the analytical and clinical performance of the test system itself, not for an algorithm that learns from data.

9. How the ground truth for the training set was established:

As the device is an in vitro diagnostic measurement system and not an AI/ML algorithm that requires a training set, the concept of "ground truth for the training set" is not applicable here.

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