Predicate Devices

Hemoccult ® BRAND Routine Screening Test for Fecal Occult Blood Manufactured by SmithKline Diagnostics, Inc.

Reference Devices

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AI/ML (Artificial Intelligence / Machine Learning)

No
The device is described as a rapid, visually read, qualitative immunochemical chromatographic method. There are no mentions of AI, ML, image processing, or complex algorithms beyond standard analytical methods. The performance studies focus on analytical and clinical metrics typical of a traditional diagnostic test.

Therapeutic

No
The device is described as a "screening aid" for detecting lower gastrointestinal disorders, and its purpose is to detect human hemoglobin in fecal samples, which points to a diagnostic function rather than a therapeutic one.

Diagnostic

Yes
The device is described as a "rapid, visually read, qualitative immunochemical chromatographic method for detection of human hemoglobin from blood in fecal samples" used as "screening aids for detecting primarily lower gastrointestinal (g.i.) disorders." This clearly indicates its use in identifying diseases or conditions, which aligns with the definition of a diagnostic device.

SaMD (Software as a Medical Device)

No

The device is described as a "rapid, visually read, qualitative immunochemical chromatographic method" for detecting hemoglobin in fecal samples. This description points to a physical test kit or strip, not a software-only device. The performance studies also describe analytical and clinical performance related to a physical test, not software.

IVD (In Vitro Diagnostic)

Yes, this device is an IVD (In Vitro Diagnostic).

Here's why:

Intended Use: The intended use explicitly states it's a "rapid, visually read, qualitative immunochemical chromatographic method for detection of human hemoglobin from blood in fecal samples." This describes a test performed in vitro (outside the body) on a biological sample (fecal sample) to provide information about a person's health status (presence of occult blood).
Sample Type: It uses a fecal sample, which is a biological specimen.
Method: It employs an "immunochemical chromatographic method," which is a laboratory technique used for diagnostic testing.
Purpose: It's used as a "screening aid for detecting primarily lower gastrointestinal (g.i.) disorders." This is a diagnostic purpose.

The definition of an IVD is a medical device that is used to examine specimens taken from the human body to provide information for diagnosis, monitoring, or screening. The FlexSure ® OBT fits this definition perfectly.

PCCP (Predetermined Change Control Plan) Authorized

N/A

Overview

Intended Use / Indications for Use

The FlexSure ® OBT (Occult Blood Test) is a rapid, visually read, qualitative immunochemical chromatographic method for detection of human hemoglobin from blood in fecal samples. Fecal occult blood tests are useful screening aids for detecting primarily lower gastrointestinal (g.i.) disorders that may be related to iron deficiency anemia, diverticulitis, ulcerative colitis, polyps, adenomas, colorectal cancers or other g.i. lesions that can bleed. FlexSure ® OBT is recommended for use by health professionals as part of routine physical examinations or when lower g.i. disorders are suspected.

Product codes (comma separated list FDA assigned to the subject device)

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Device Description

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Mentions image processing

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Mentions AI, DNN, or ML

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Input Imaging Modality

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Anatomical Site

lower gastrointestinal (g.i.)

Indicated Patient Age Range

Not Found

Intended User / Care Setting

health professionals

Description of the training set, sample size, data source, and annotation protocol

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Description of the test set, sample size, data source, and annotation protocol

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Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)

Analytical Performance Studies

Analytical Sensitivity:
- Lower Sensitivity Limit: In vitro studies demonstrated that following the recommended procedures for sample collection and storage, FlexSure OBT reliably detected 0.2 mL or more of added blood per 100 g of feces (0.3 mg hemoglobin per g of stool). This level of blood is approximately equal to 2 to 3 mL of daily in vivo lower g.i. bleeding.
- Prozone Effect: In vitro studies demonstrated that FlexSure® OBT reliably detected up to 17 mL of added blood per 100 g of feces (25 mg hemoglobin per g of stool). At this level and above, blood is generally visible in the stool.
Accuracy of Test Results:
- Cross Reactivity Studies: Individual fecal samples were spiked with horse myoglobin and hemoglobin from beef, chicken, fish, horse, pig. rabbit, goat, sheep and turkey to determine whether dietary substances cross react with the test. The FlexSure®OBT results were negative even at levels in excess of normal dietary intake or levels which consistently give false-positive results with guaiac-based tests.
- Interference / Effect of Dietary Substances: Fecal samples from different individuals spiked with excessive quantities of substances known to interfere with guaiac-based tests (plant peroxidases and ferrous iron to check for possible false-positive test results, and a mixture of vitamin C and human hemoglobin to check for possible false-negative test results) yielded 100% accurate test results with FlexSure® OBT.
- Reproducibility: The within-site and between-site reproducibility of FlexSure OBT was demonstrated with a range of blood levels spiked into stool samples to give negative, borderline positive and positive test results. The within-site reproducibility was 100% (90/90). The between-site reproducibility was 97% (30/30 for the negative, 30/30 for the positive and 27/30 for the borderline positive sample).
- Readability / Repeatability: Comparable results were obtained with experienced and inexperienced reader groups, each using fecal samples spiked with low to moderate levels of human blood. The results indicated greater than 95% agreement among the two reader groups except at the analytical cutoff of the test where greater variation is expected. The "experienced" group was comprised of three SKD technicians who had used the test extensively, one with a doctorate degree and two with BA/BS degrees. The "inexperienced" group consisted of 16 individuals with varied educational backgrounds from High School to M.D. located in the U.S., Europe, Australia and Canada.

Clinical Performance Studies

Average Risk Screening:
- Apparent Specificity and Positive Predictive Value in a Comparison of Paired Fecal Occult Blood Tests: The performance of FlexSure®OBT in an average risk screening population of 1,734 individuals on a restricted diet yielded an apparent specificity for colorectal neoplasia of 98.4% (1,702/1,729) for FlexSure® OBT and 97.2% (1,680/1,729) for Hemoccult . For any lower g.i. pathology, the apparent specificity was 99.0% (1,666/1,682) for FlexSure "OBT and 98.8% (1.661/1.682) for Hemoccult . The positive predictive value for colorectal neoplasia was 15.6% (5/32) for FlexSure® OBT and 3.9% (2/51) for Hemoccult".
High Risk Population:
- Sensitivity: The performance of FlexSure® OBT in a high risk population of 283 individuals with a personal or family history of colorectal cancer or adenomas who were on a restricted diet yielded a relative sensitivity for colorectal neoplasia of 55.6% (25/45) for FlexSure OBT and 51.1% (23/45) for Hemoccult . The Negative Predictive Values were not calculated for this group since this parameter is only meaningful in a screening population.
Studies With Presumed Normal Subjects:
- Lower G.I. Specificity: The apparent specificity (an estimate of specificity due to the inability and inappropriateness of performing colonoscopy on individuals with a negative FOBT result) of FlexSure® OBT for lower gastrointestinal pathology using a group of 88 presumed normal young adults was 97.7% (86/88).
- Effect of Diet: The specificity of FlexSure® OBT for human hemoglobin in 19 presumed normal subjects on restricted, unrestricted, and rare red meat diets was tested. FlexSure®OBT yielded a specificity of 100% regardless of diet.
- Simulated Upper G.I. Bleeding: The specificity of FlexSure® OBT for lower g.i. bleeding was studied in a group of presumed normal volunteers who ingested their own blood to simulate upper g.i. bleeding. FlexSure® OBT yielded a specificity of 100% in the four individuals who participated in the study.

Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)

Sensitivity:
- Analytical: Detected 0.2 mL or more of added blood per 100 g of feces.
- Clinical (High Risk Population): 55.6% (25/45) for FlexSure OBT; 51.1% (23/45) for Hemoccult.
Specificity:
- Clinical (Average Risk Screening, colorectal neoplasia): 98.4% (1,702/1,729) for FlexSure® OBT; 97.2% (1,680/1,729) for Hemoccult.
- Clinical (Average Risk Screening, any lower g.i. pathology): 99.0% (1,666/1,682) for FlexSure "OBT; 98.8% (1.661/1.682) for Hemoccult.
- Clinical (Lower G.I. Specificity in presumed normal subjects): 97.7% (86/88).
- Clinical (Effect of Diet in presumed normal subjects): 100%.
- Clinical (Simulated Upper G.I. Bleeding): 100%.
Positive Predictive Value (PPV):
- Clinical (Average Risk Screening, colorectal neoplasia): 15.6% (5/32) for FlexSure® OBT; 3.9% (2/51) for Hemoccult.
Reproducibility:
- Within-site: 100% (90/90).
- Between-site: 97% (30/30 for negative, 30/30 for positive, 27/30 for borderline positive).
Readability / Repeatability: Greater than 95% agreement among experienced and inexperienced reader groups, except at analytical cutoff.

Predicate Device(s): If the device was cleared using the 510(k) pathway, identify the Predicate Device(s) K/DEN number used to claim substantial equivalence and list them here in a comma separated list exactly as they appear in the text. List the primary predicate first in the list.

Hemoccult ® BRAND Routine Screening Test for Fecal Occult Blood Manufactured by SmithKline Diagnostics, Inc.

Reference Device(s): Identify the Reference Device(s) K/DEN number and list them here in a comma separated list exactly as they appear in the text.

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Predetermined Change Control Plan (PCCP) - All Relevant Information for the subject device only (e.g. presence / absence, what scope was granted / cleared under the PCCP, any restrictions, etc).

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Regulation Number and Section

§ 864.6550 Occult blood test.

(a)
Identification. An occult blood test is a device used to detect occult blood in urine or feces. (Occult blood is blood present in such small quantities that it can be detected only by chemical tests of suspected material, or by microscopic or spectroscopic examination.)(b)
Classification. Class II (special controls). A control intended for use with an occult blood test is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 864.9.

Summary

0

K961062

This 510(k) summary of safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990.

| Manufacturer: | SmithKline Diagnostics, Inc.
1050 Page Mill Rd.
Palo Alto, CA 94303-0105
Attention: Ronald J. Schoengold |
|----------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Proprietary Name: | FlexSure ® OBT |
| Classification Name: | Occult Blood Reagent |
| Intended Use: | The FlexSure ® OBT (Occult Blood Test) is a rapid, visually
read, qualitative immunochemical chromatographic method for
detection of human hemoglobin from blood in fecal samples.
Fecal occult blood tests are useful screening aids for detecting
primarily lower gastrointestinal (g.i.) disorders that may be related
to iron deficiency anemia, diverticulitis, ulcerative colitis, polyps,
adenomas, colorectal cancers or other g.i. lesions that can bleed.
FlexSure ® OBT is recommended for use by health professionals as
part of routine physical examinations or when lower g.i. disorders
are suspected. |
| Predicate Product: | Hemoccult ® BRAND Routine Screening Test for Fecal Occult
Blood Manufactured by SmithKline Diagnostics, Inc. |
| Performance Summary: | The FlexSure ® OBT Immunochemical Fecal Occult Blood Test
is substantially equivalent to the predicate device Hemoccult ®, sold
prior to May 28, 1976. The performance of FlexSure ® OBT was
verified by sensitivity, specificity, cross reactivity, interference,
reproducibility and readability studies in laboratory and clinical
settings. Refer to the attached PERFORMANCE
CHARACTERISTICS. |

Kasen L.M.S. for Marshall C. McCarthy
Marshall C. McCarthy

Manager, Regulatory Affairs

10/28/96
Date

000015

1

PERFORMANCE CHARACTERISTICS

Background

Fecal occult blood testing (FOBT) is utilized worldwide as a screening aid for persons 50 years of age or older to detect gastrointestinal (g.i.) bleeding disorders. Recent studies indicate that detection of 2 mL or more of daily g.i. blood loss can be an early indicator of significant lower g.i. pathology including colorectal neoplasia (adenomas ≥1cm and colorectal cancers.)

Analytical Performance Studies

ANALYTICAL SENSITIVITY:

♦ Lower Sensitivity Limit In vitro studies demonstrated that following the recommended procedures for sample collection and storage, FlexSure OBT reliably detected 0.2 mL or more of added blood per 100 g of feces (0.3 mg hemoglobin per g of stool). This level of blood is approximately equal to 2 to 3 mL of daily in vivo lower g.i. bleeding.
♦ Prozone Effect In vitro studies demonstrated that FlexSure® OBT reliably detected up to 17 mL of added blood per 100 g of feces (25 mg hemoglobin per g of stool). At this level and above, blood is generally visible in the stool.

ACCURACY OF TEST RESULTS:

◆ Cross Reactivity Studies Individual fecal samples were spiked with horse myoglobin and hemoglobin from beef, chicken, fish, horse, pig. rabbit, goat, sheep and turkey to determine whether dietary substances cross react with the test. The FlexSure®OBT results were negative even at levels in excess of normal dietary intake or levels which consistently give false-positive results with guaiac-based tests.

2

ACCURACY OF TEST RESULTS (continued):

♦ Interference / Effect of Dietary Substances Fecal samples from different individuals spiked with excessive quantities of substances known to interfere with guaiac-based tests (plant peroxidases and ferrous iron to check for possible false-positive test results, and a mixture of vitamin C and human hemoglobin to check for possible false-negative test results) vielded 100% accurate test results with FlexSure® OBT.
♦ Reproducibility The within-site and between-site reproducibility of FlexSure OBT was demonstrated with a range of blood levels spiked into stool samples to give negative, borderline positive and positive test results. The within-site reproducibility was 100% (90/90). The between-site reproducibility was 97% (30/30 for the negative, 30/30 for the positive and 27/30 for the borderline positive sample).
� Readability / Repeatability Comparable results were obtained with experienced and inexperienced reader groups, each using fecal samples spiked with low to moderate levels of human blood. The results indicated greater than 95% agreement among the two reader groups except at the analytical cutoff of the test where greater variation is expected. The "experienced" group was comprised of three SKD technicians who had used the test extensively, one with a doctorate degree and two with BA/BS degrees. The "inexperienced" group consisted of 16 individuals with varied educational backgrounds from High School to M.D. located in the U.S., Europe, Australia and Canada.

3

Clinical Performance Studies

AVERAGE RISK SCREENING:

� Apparent Specificity and Positive Predictive Value in a Comparison of Paired Fecal Occult Blood Tests - The performance of FlexSure®OBT in an average risk screening population of 1,734 individuals on a restricted diet vielded an apparent specificity for colorectal neoplasia of 98.4% (1,702/1,729) for FlexSure® OBT and 97.2% (1,680/1,729) for Hemoccult . For any lower g.i. pathology, the apparent specificity was 99.0% (1,666/1,682) for FlexSure "OBT and 98.8% (1.661/1.682) for Hemoccult . The positive predictive value for colorectal neoplasia was 15.6% (5/32) for FlexSure® OBT and 3.9% (2/51) for Hemoccult".

HIGH RISK POPULATION:

♦ Sensitivity The performance of FlexSure® OBT in a high risk population of 283 individuals with a personal or family history of colorectal cancer or adenomas who were on a restricted diet yielded a relative sensitivity for colorectal neoplasia of 55.6% (25/45) for FlexSure OBT and 51.1% (23/45) for Hemoccult . The Negative Predictive Values were not calculated for this group since this parameter is only meaningful in a screening population.

STUDIES WITH PRESUMED NORMAL SUBJECTS:

◆ Lower G.I. Specificity The apparent specificity (an estimate of specificity due to the inability and inappropriateness of performing colonoscopy on individuals with a negative FOBT result) of FlexSure® OBT for lower gastrointestinal pathology using a group of 88 presumed normal young adults was 97.7% (86/88).
♦ Effect of Diet The specificity of FlexSure® OBT for human hemoglobin in 19 presumed normal subjects on restricted, unrestricted, and rare red meat diets was tested. FlexSure®OBT yielded a specificity of 100% regardless of diet.

4

STUDIES WITH PRESUMED NORMAL SUBJECTS (continued):

♦ Simulated Upper G.I. Bleeding The specificity of FlexSure® OBT for lower g.i. bleeding was studied in a group of presumed normal volunteers who ingested their own blood to simulate upper g.i. bleeding. FlexSure® OBT yielded a specificity of 100% in the four individuals who participated in the study.