(268 days)
The DUS R-50S System provides a qualitative measurements for specific gravity, pH, leukocytes, nitrite, protein, glucose, ketone, urobilinogen, bilirubin, blood, microalbumin and creatinine in urine specimens. These measurements are used to aid in the diagnosis of metabolic disorders, kidney function anomalies, urinary tract infections and liver function. The system is intended for prescription, in vitro diagnostic use only.
The DUS R-50S (Urine Chemistry system) is a portable analyzer. It is designed to read only DUS Series for urinalysis. This analyzer reports semi-quantitatively assays for 12 urine analytes [Leukocyte, Nitrite, Urobilinogen, Protein, pH, Blood, Specific gravity, Ketone, Bilirubin, Glucose, Microalbumin, Creatinine]. Reagent strip results are automatically displayed on the screen. The DUS R-50S is intended for in vitro diagnostic use only
The DUS R-50S (Urine Chemistry system) device is intended for qualitative and semi-quantitative measurements of various analytes in urine specimens to aid in diagnosing metabolic disorders, kidney function anomalies, urinary tract infections, and liver function.
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 acceptance criteria are generally implied by the requirement for "very high concordance of between 90-100%" with the predicate device and the "majority of analysis display 90-100 % concordance over all blocks." The detailed "Exact agreement (%)" and "Within one block (%)" values for each analyte serve as the reported device performance against these implicit acceptance criteria.
| Analyte | Acceptance Criteria (Implied) | Reported Device Performance (Exact agreement %) | Reported Device Performance (Within one block %) |
|---|---|---|---|
| Urobilinogen | 90-100% concordance | 99.3% | 100% |
| Glucose | 90-100% concordance | 99.2% | 100% |
| Bilirubin | 90-100% concordance | 99% | 100% |
| Ketones | 90-100% concordance | 98.7% | 100% |
| Blood | 90-100% concordance | 97% | 100% |
| Protein | 90-100% concordance | 98% | 100% |
| Nitrite | 90-100% concordance | 99.5% | 100% |
| Leukocytes | 90-100% concordance | 98% | 100% |
| pH | 90-100% concordance | 94.3% | 100% |
| Specific Gravity | 90-100% concordance | 94.9% | 100% |
| Creatinine | 90-100% concordance | 94.3% | 100% |
| Microalbumin | 90-100% concordance | 98.4% | 100% |
2. Sample Size Used for the Test Set and Data Provenance
The method comparison study was conducted with a total of 867 samples. The data provenance is described as being collected at three clinical sites. The document does not specify the country of origin of the data, but the submitter information lists DFI Co., Ltd. in Korea. The study appears to be retrospective, as it compares the new device results against a legally marketed predicate device using collected samples.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and their Qualifications
The document does not explicitly mention the use of experts to establish ground truth for the test set. Instead, the performance is evaluated by "method comparison" against a predicate device (Siemens Clinitek Status + urine chemistry instrument). The predicate device's results are considered the reference for comparison.
4. Adjudication Method for the Test Set
There is no mention of an adjudication method involving human experts for the test set. The comparison is directly between the new device and the predicate device.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
A multi-reader multi-case (MRMC) comparative effectiveness study was not conducted as per the provided information. The study focuses on comparing the new device's analytical performance against a predicate device, not on human reader performance with or without AI assistance.
6. Standalone Performance Study
Yes, a standalone performance study was done in the form of a method comparison study where the DUS R-50S (DUS R-50S instrument, DUS10 and DUS2AC reagent strips) was compared to the predicate device (Siemens Clinitek Status + urine chemistry instrument using Multistix 10SG and CLINITEK Microalbumin 2 test strips). This evaluates the algorithm and device's performance directly.
7. Type of Ground Truth Used
The "ground truth" for the test set was the results obtained from the predicate device, specifically the Siemens Clinitek Status + urine chemistry instrument using Multistix 10SG and CLINITEK Microalbumin 2 test strips.
8. Sample Size for the Training Set
The document does not explicitly specify a separate sample size for a "training set." The performance evaluation focuses on the method comparison study using 867 samples. For a 510(k) submission for an in vitro diagnostic device, the manufacturer typically performs internal validation and verification studies during development, but the detailed breakdown of training data vs. test data for algorithm development is not typically part of the regulatory submission summary provided.
9. How the Ground Truth for the Training Set Was Established
Since a "training set" is not explicitly mentioned or detailed, the method for establishing its ground truth is not provided. If an algorithm was developed using machine learning, the ground truth for training would generally be established by laboratory reference methods or expert interpretation of the results from traditional methods, similar to how the predicate device results are used for the test set.
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February 16, 2018
DFI CO., LTD. % HO DONG YANG, CEO ONBIX CORPORATION #821 SAMIL PLAZA, 14, DOGOK-RO 1-GIL GANGNAM-GU, SEOUL, KOREA 06523
Re: K171521
Trade/Device Name: DUS R-50S (Urine Chemistry system) Regulation Number: 21 CFR 862.1340 Regulation Name: Urinary glucose (nonquantitative) test system Regulatory Class: Class II Product Code: JIL, JIO, JFY, JIR, LJX, JMT, CDM, CEN, JRE, JIN, JJB, KQO Dated: December 27, 2017 Received: January 10, 2018
Dear Ho Dong Yang:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR
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Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/) and CDRH Learn (http://www.fda.gov/Training/CDRHLearn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (http://www.fda.gov/DICE) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
Sincerely,
Courtney H. Lias -S
Courtney H. Lias, Ph.D. Director Division of Chemistry and Toxicology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health
Enclosure
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Indications for Use
510(k) Number (if known) K171521
Device Name DUS R-50S (Urine Chemistry system)
Indications for Use (Describe)
The DUS R-50S System provides a qualitative measurements for specific gravity, pH, leukocytes, nitrite, protein, glucose, ketone, urobilinogen, bilirubin, blood, microalbumin and creatinine in urine specimens. These measurements are used to aid in the diagnosis of metabolic disorders, kidney function anomalies, urinary tract infections and liver function. The system is intended for prescription, in vitro diagnostic use only.
The DUS R-50S System consists of the following:
DUS R-50S Analyzer
DUS 10 Reagent Strips for urinalysis include test pads for leukocytes, nitrite, urobilinogen, protein, pH, blood, specific gravity, ketone(acetoacetic acid), bilirubin and glucose.
DUS 2AC Reagent Strips for urinalysis include test pads for microalbumin and creatinine.
| Type of Use (Select one or both, as applicable) | |
|---|---|
|X Prescription Use (Part 21 CFR 801 Subpart D)
| | Over-The-Counter Use (21 CFR 801 Subpart C)
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510(k) SUMMARY [K171521]
This 510(k) summary is being submitted in accordance with the requirements of 21 CFR §807.92.
| Submitter Information: | DFI Co., Ltd.388-25, Gomo-ro, Jillye-myeon, Gimhae-sIGyeongsangnam-do, 621-881, KoreaTel. +82-55-346-1882 Fax: +82-55-346-1883 |
|---|---|
| Contact Person: | Ho Dong, YangOnbix Corporation#821 Samil Plaza, 14 Dogokro 1-gilGangnam-gu, Seoul, Korea (06253)Tel: *82-2-566-3360 / Fax: *82-2-6280-3360Email: onbix@naver.com |
| Date Summary Prepared: | Feb 15, 2018 |
| Device Information: | |
| Trade Name(s): | DUS R-50S (Urine Chemistry system) |
Common Name: Automated urinalysis system
Regulatory information:
| Name | Regulation | Product code | Device class |
|---|---|---|---|
| Urinary Glucose (non-quantitative) test system | 21 CFR § 862.1340 | JIL | II |
| Occult Blood test | 21 CFR 864.6550 | JIO | II |
| Creatinine test system | 21 CFR 862.1225 | JFY | II |
| Urinary Protein or Albumin (nonquantitative) test system | 21 CFR 862.1645 | JIR | I |
| Leukocyte peroxidase | 21 CFR 864.7675 | LJX | I |
| Nitrite (nonquantitative) test system | 21 CFR 862.1510 | JMT | I |
| Urinary Urobilinogen | 21 CFR 862.1785 | CDM | I |
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| (nonquantitative) test system | |||
|---|---|---|---|
| Urinary pH (nonquantitative) test | 21 CFR 862.1550 | CEN | I |
| Specific Gravity | 21 CFR 862.2800 | JRE | I |
| Ketones (nonquantitative) test system | 21 CFR 862.1435 | JIN | I |
| Urinary Bilirubin and its conjugates(nonquantitative) test system | 21 CFR 862.1115 | JJB | I |
| Automated Urinalysis System | 21 CFR 862.2900 | KQO | I |
Predicate Device Information:
K091216 / Clinitek Status+
Device Description:
The DUS R-50S (Urine Chemistry system) is a portable analyzer. It is designed to read only DUS Series for urinalysis. This analyzer reports semi-quantitatively assays for 12 urine analytes [Leukocyte, Nitrite, Urobilinogen, Protein, pH, Blood, Specific gravity, Ketone, Bilirubin, Glucose, Microalbumin, Creatinine]. Reagent strip results are automatically displayed on the screen. The DUS R-50S is intended for in vitro diagnostic use only
Indications for Use:
The DUS R-50S (Urine Chemistry System) provides a qualitative and semiquantitative measurements for specific gravity, pH, leukocytes, nitrite, protein, glucose, ketone, urobilinogen, bilirubin, blood, microalbumin and creatinine in urine specimens. These measurements are used to aid in the diagnosis of metabolic disorders, kidney function anomalies, urinary tract infections and liver function. The system is intended for prescription, in vitro diagnostic use only.
The DUS R-50S (Urine Chemistry System) consists of the following:
- DUS R-50S Analyzer
-
DUS 10 Reagent Strips for urinalysis include test pads for leukocytes, nitrite, urobilinogen, protein, pH, blood, specific gravity, ketone (acetoacetic acid), bilirubin and glucose.
-
DUS 2AC Reagent Strips for urinalysis include test pads for microalbumin and creatinine.
Comparison to Predicate Device(s):
The DUS R-50S (Urine Chemistry System) is equivalent to the predicate devices in its intended use and technological characteristics, including:
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-
- indications for use
-
- technological characteristics
-
- performance properties
Summary of testing:
To be in compliance with electromagnetic safety and compatibility, appropriate study has been applied to the new device.
The performance characteristic of the DUS R-50S (Urine Chemistry System) were verified by method comparison, precision, detection limit, interference, specificity, shelf life and stress studies. Testing is summarized below.
Performance Characteristics
a. Precision/Reproducibility
The repeatability / reproducibility precisions were tested at three Clinical sites, using commercially Quantimetrix Dipper Urine Dipstick Control Level 1 and Level 2. The agreements of results are shown above 95%.
| Level 1 control | |||||
|---|---|---|---|---|---|
| Test Results | Within-run (90) | Within-day (90) | |||
| Item | Agreement (%) | Agreement within | Agreement (%) | Agreement within +/-1block (%) | |
| Urobilinogen | Normal | 90/90 | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Glucose | Negative | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Bilirubin | Negative | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Ketones | Negative | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| SG | 1.020 | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Blood | Negative | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| pH | 6 | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Protein | Negative | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Nitrite | Negative | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Leukocytes | Negative | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Creatinine | 10mg/dL | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Microalbumin | 10mg/L | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
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| Level 2 control | |||||
|---|---|---|---|---|---|
| Item | TestResults | Within-run (90) | Within-day (90) | ||
| Agreement(%) | Agreementwithin | Agreement(%) | Agreement within+/-1 block (%) | ||
| Urobilinogen | 4 mg/dL | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Glucose | 1000 | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Bilirubin | 4 mg/dL | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Ketones | 40 mg/dL | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| SG | 1.020 | 89/90 (98.9%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Blood | 120 | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| PH | 7 | 90/90 (100%) | 90/90 (100%) | 89/90 (98.9%) | 90/90 (100%) |
| Protein | 100 mg/dL | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Nitrite | Positive | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Leukocytes | 70 | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Creatinine | 200mg/dL | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
| Microalbumin | 150mg/L | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) | 90/90 (100%) |
b. Linearity /assay reportable range.
Linearity / assay reportable range were tested at DFI Clinical center. Samples were created by spiking known concentration of each standard material or by serial dilution of a high concentration with negative urine. Test results indicated that there was no significant difference between the samples of known concentration result and result of DUS R-50s.
Results of summarized below:
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| Analyte | Urine sample concentrationtested | Color block output | % Exact match |
|---|---|---|---|
| Urobilinogen | Negative/Norm | 0.1 | 100% (90/90) |
| 1 mg/dL | 1 mg/dL | 100% (90/90) | |
| 2 mg/dL | 2 mg/dL | 98.8% (89/90) | |
| 4 mg/dL | 4 mg/dL | 98.8% (89/90) | |
| 8 mg/dL | 8 mg/dL | 100% (90/90) | |
| Glucose | Negative | Neg. | 100% (90/90) |
| 100 mg/dL | ± (100 mg/dL) | 100% (90/90) | |
| 250 mg/dL | +250 mg/dL | 98.8% (89/90) | |
| 500 mg/dL | ++500 mg/dL | 96.6% (87/90) | |
| 1000 mg/dL | +++ 1000 mg/dL | 98.8% (89/90) | |
| 2000 mg/dL | ++++2000 mg/dL | 100% (90/90) | |
| Bilirubin | Negative | Neg. | 100% (90/90) |
| 1 mg/dL | + | 98.8% (89/90) | |
| 2 mg/dL | ++ | 98.8% (89/90) | |
| 4 mg/dL | +++ | 100% (90/90) | |
| Ketones | Negative | Neg. | 100% (90/90) |
| 5 mg/dL | ± 5 mg/dL | 100% (90/90) | |
| 15 mg/dL | + 15 mg/dL | 96.6% (87/90) | |
| 40 mg/dL | ++ 40 mg/dL | 98.8% (89/90) | |
| 80 mg/dL | +++ 80 mg/dL | 97.7% (88/90) | |
| 160 mg/dL | ++++ 160 mg/dL | 100% (90/90) | |
| Specificgravity | 1.000 | 1.000 | 100% (90/90) |
| 1.005 | 1.005 | 98.8% (89/90) | |
| 1.010 | 1.010 | 97.7% (88/90) | |
| 1.015 | 1.015 | 96.6% (87/90) | |
| 1.020 | 1.020 | 98.8% (89/90) | |
| 1.025 | 1.025 | 96.6% (87/90) | |
| 1.030 | 1.030 | 100% (90/90) | |
| Nitrite | Negative | Neg. | 100% (90/90) |
| 0.05 mg/dL | Trace | 100% (90/90) | |
| 10 mg/dL | Pos | 100% (90/90) | |
| Blood | Negative | Neg | 100% (90/90) |
| 10 RBC/μL | Trace | 100% (90/90) | |
| 25 RBC/μL | + 25 RBC/μL | 100% (90/90) | |
| 80 RBC/μL | ++ 80 RBC/μL | 98.8% (89/90) | |
| 200 RBC/μL | +++ 200 RBC/μL | 97.7% (88/90) | |
| pH | 5 | 5 | 100% (90/90) |
| 6 | 6 | 98.8% (89/90) | |
| 6.5 | 6.5 | 98.8% (89/90) | |
| 7 | 7 | 98.8% (89/90) | |
| 7.5 | 7.5 | 97.7% (88/90) | |
| 8 | 8 | 100% (90/90) | |
| 8.5 | 8.5 | 100% (90/90) | |
| Protein | Negative | Neg. | 100% (90/90) |
| 15 mg/dL | Trace | 98.8% (89/90) | |
| 30mg/dL | (+) 30 mg/dL | 97.7% (88/90) | |
| 100 mg/dL | (++) 100 mg/dL | 97.7% (88/90) | |
| 300 mg/dL | (+++) 300 mg/dL | 97.7% (88/90) | |
| 1000 mg/dL | (++++) 1000 mg/dL | 100% (90/90) | |
| Leukocytes | Negative | Negative | 100% (90/90) |
| 15 WBC/μL | 15 WBC/μL | 100% (90/90) | |
| 70 WBC/μL | 70 WBC/μL | 97.7% (88/90) | |
| 125 WBC/μL | 125 WBC/μL | 97.7% (88/90) | |
| 500 WBC/μL | 500 WBC/μL | 98.8% (89/90) | |
| Microalbumin | 10 mg/dL | 10 mg/dL | 100% (90/90) |
| 30 mg/dL | 30 mg/dL | 98.8% (89/90) | |
| 80 mg/dL | 80 mg/dL | 97.7% (88/90) | |
| 150 mg/dL | 150 mg/dL | 98.8% (89/90) | |
| Creatinine | 10 mg/dL | 10 mg/dL | 100% (90/90) |
| 50 mg/dL | 50 mg/dL | 100% (90/90) | |
| 100 mg/dL | 100 mg/dL | 98.8% (89/90) | |
| 200 mg/dL | 200 mg/dL | 96.6% (87/90) | |
| 300 mg/dL | 300 mg/dL | 97.7% (88/90) |
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The report ranges for the DUS 10 reagent strips are of each analyte are summarized below:
| Test | Reportable Range | |
|---|---|---|
| Urobilinogen | Qualitative: normal to 3+Semi-quantitative: 0.1 - 8 mg/dL | |
| Glucose | Qualitative: Negative to 4+Semi-quantitative: Neg - 2000 mg/dL | |
| Bilirubin | Qualitative: normal to 3+Semi-quantitative: Neg - 4 mg/dL |
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| Ketones | Qualitative: Negative to 4+Semi-quantitative: Neg – 160 mg/dL | |
|---|---|---|
| Specific Gravity | 1.000 - 1.030 | |
| Blood | Qualitative: normal to 3+Semi-quantitative: Neg – 200 RBC/ µL | |
| pH | 5 – 8.5 | |
| Protein | Qualitative: Negative to 4+Semi-quantitative: Neg – 1000 mg/dL | |
| Nitrite | Semi-quantitative: Neg – 10 mg/dL | |
| Leukocytes | Qualitative: normal to 3+Semi-quantitative: Neg - 500 WBC/µL | |
| Microalbumin | Semi-quantitative: 10 – 150 mg/L | |
| Creatinine | Semi-quantitative: 10 – 300 mg/dL |
The reportable ranges for DUS 2AC reagent strips are:
| Microalbumin | Semi-quantitative: 10 - 150 mg/L |
|---|---|
| Creatinine | Semi-quantitative: 10 - 300 mg/dL |
c. Detection limit
A sensitivity study was performed to evaluate the lower limits of detection for each the analytes on the DUS strips (DUS 10, DUS 2AC) utilizing the DUS R-50S analyzer. Negative urine was spiked with standard materials to obtain the desired concentrations. 90 replicates were obtained for each concentration. Sensitivity was defined as the cutoff in which ≥95% of the contrived pooled measurements were trace or the first positive result. The pH, specific gravity and creatinine were not evaluated for the lower limits of sensitivity.
| Analyte | Concentration | Negativeresult | Positive(+ 2 mg/dL) | Positive Agreement(%) |
|---|---|---|---|---|
| Urobilinogen | 1.8 EU/dL | 8 | 82 | 91.1% |
| 2 EU/dL | 0 | 90 | 100% | |
| 2.3 EU/dL | 0 | 90 | 100% | |
| Result cut-off | 2 Eu/dL | |||
| Glucose | Concentration | Negative | Positive | Positive Agreement |
| result | (±100mg/dL) | (%) | ||
| 80 mg/dL | 5 | 85 | 94.4% | |
| 100 mg/dL | 0 | 90 | 100% | |
| 120 mg/dL | 0 | 90 | 100% | |
| Result cut-off | 100 mg/dL | |||
| Concentration | Negativeresult | Positive(+1.0 mg/dL) | Positive Agreement(%) | |
| Bilirubin | 0.8 mg/dL | 6 | 84 | 93.3% |
| 1.0 | 0 | 90 | 100% | |
| 1.2 | 0 | 90 | 100% | |
| Result cut-off | 1.0 mg/dL | |||
| Concentration | Negativeresult | Positive(± 5 mg/dL) | Positive Agreement(%) | |
| Ketone | 4 mg/dL | 5 | 85 | 94.4% |
| 5 mg/dL | 0 | 90 | 100% | |
| 6 mg/dL | 0 | 90 | 100% | |
| Result cut-off | 5 mg/dL | |||
| Concentration | Negativeresult | Positive(± 5 mg/dL) | Positive Agreement(%) | |
| Blood | 8 RBC/µL | 7 | 83 | 92.2% |
| 10 RBC/µL | 0 | 90 | 100% | |
| 12 RBC/μL | 0 | 90 | 100% | |
| Result cut-off | 10 RBC/µL | |||
| Concentration | Negativeresult | Positive(±15 mg/dL) | Positive Agreement(%) | |
| Protein | 12 mg/dL | 6 | 84 | 93.3% |
| 15 mg/dL | 0 | 90 | 100% | |
| 18 mg/dL | 0 | 90 | 100% | |
| Result cut-off | 15 mg/dL | |||
| Concentration | Negativeresult | Positive(0.05 mg/dL) | Positive Agreement(%) | |
| Nitrite | 0.04 mg/dL | 6 | 84 | 93.3% |
| 0.05 mg/dL | 0 | 90 | 100% | |
| 0.06 mg/dL | 0 | 90 | 100% | |
| Result cut-off | 0.05 mg/dL | |||
| Concentration | Negativeresult | Positive(15WBC/μL) | Positive Agreement(%) | |
| Leukocytes | 12 WBC/μL | 5 | 85 | 94.4% |
| 15 WBC/μL | 0 | 90 | 100% | |
| 18 WBC/μL | 0 | 90 | 100% | |
| Result cut-off | 15 WBC/μL | |||
| Concentration | Negativeresult | Positive(3 mg/dL) | Positive Agreement(%) | |
| Microalbumin | 2 mg/dL | 8 | 82 | 91.1% |
| 3 mg/dL | 0 | 90 | 100% | |
| 4 mg/dL | 0 | 90 | 100% | |
| Result cut-off | 3 mg/dL |
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d. Analytical specificity:
No interference was observed for the following compounds at the concentrations evaluated below:
| Potential Interfering Substance | Highest concentration at which nointerference was observed |
|---|---|
| Albumin (protein) | 750 mg/dL |
| Ascorbic acid | 15 mg/dL |
| Acetaminophen | 25 mg/dL |
| Azo gantrinsin (Sulfamethoxazol) | 140 mg/dL |
| Bilirubin | 3 mg/dL |
| Captropril | 100 mg/dL |
| Sodium hypochlorite | 0.1% |
| Creatinine | 800 mg/dL |
| Nitrofurantion | 10 mg/dL |
| Oxalic acid | 30 mg/dL |
| p-amno Salicylic acid | 375 mg/dL |
| ß-D-Glucose (Glucose) | 1000 mg/dL |
| Phenazopyridine | 25 mg/dL |
| Riboflavin | 12 mg/dL |
| Selenium | 150 mg/dL |
| Forrmaldehyde | 100 mg/dL |
| Hemoglobin | 3 mg/dL |
| Lithium acetoacetate (ketones) | 20 mg/dL |
| Tetracycline | 20 mg/dL |
| Urobilinogen | 10 mg/dL |
| pH | 7 |
| Specific gravity | 1.030 |
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e. Analytical specificity / Limitation
As with all laboratory tests, definitive diagnostic or therapeutic decisions should not be based on any single result of method. Substances that cause abnormal urine color may affect the readability of test pads in urinalysis reagent strips. Urinary ascorbic acid concentrations as low as 40mg/dl can cause interference in specimens with low concentrations of glucose, blood, nitrite and bilirubin.
Urobilinogen: The absence of urobilinogen in the specimen can't be determined. The test area will react with interfering substances known to react with Ehrlich's reagent, such as p- aminosalicylic acid. Drugs containing azo gantrisin (sulfamethoxazol) or high Bilirubin may give a masking golden color. Preservative Formaldehyde may cause false negative. The test is not reliable method for the detection of porphobilinogen.
Glucose: Ascorbic acid (more than 40mg/dl) may cause false negative result at the low level of glucose. Ketones reduce the sensitivity of the test. Moderately high ketone level (> 40mg/dl) may cause a false negative for specimen containing small amount of glucose (100mg/dl). Chlorine Bleach (≥1%), low SG and formaldehyde urine may cause false positive result at the low level.
Bilirubin: Metabolites of drugs, such as selenium(>220mg/dL), phenazopvridine(>37mg/dL) may cause false positives. p-Amino salicylic acid(>1500mg/dL) can produce a vellow-orange to red color response, which may interfere with the interpretation of false positive bilirubin readings. Ascorbic acid (>40mg/dL) may cause false negative.
Ketones: Low level false positive reactions may be seen in highly concentrated urine specimens (high specific gravity) or in specimens containing large amounts of levodopa metabolites drug such as captopril. The uroprotective drug mesna (sodium 2-mercaptoethane sulfonate) and other free-sulfhydryl compounds produce false-positive results in ketone methods that are based on the Legal reaction (alkaline sodium nitroprusside).
pH: If the excessive urine remains on the strip because of improper test procedure, it is possible that the acidic buffer in protein portion comes out and affect the pH portion, then pH result may be decreased than the actual. This phenomenon is called" run-over effect."
Blood: Elevated specific gravity or protein in urine may reduce the reactivity of the blood test portion. Microbial peroxidase associated with urinary tract infection may cause false positive results. Ascorbic acid concentrations (>30 mg/dl) may cause
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false negatives at the low level of blood. Substances that cause abnormal urine color, such as drug containing azo dyes, nitrofurantoin and riboflavin may cause false positive result. Strong oxidizing cleaning agents such as chlorine bleach cause false positive results.
Specific Gravity (SG): High-buffered alkaline urine may cause diminished result, whereas high- buffered acidic urine may cause slightly elevated result.
Protein: False positive results may be found in strongly basic urine (pH 9). The interpretation of results is also difficult in turbid urine specimens. Metabolites of drugs, such as acetaminophen, hemoglobin may cause false positives. Piements such as bilirubin and azo-containing compounds cause false result with the color reaction.
Nitrite: Ascorbic acid (>40mg/dL) may cause false negative result with low level of nitrite containing (<0.03mg) urine. The negative result does not always mean that the patient is free from bacteriuria. Pink spots or pink edges should not be interpreted as a positive result. Medication such as phenazopyridine or other azocontaining compounds or other dyes cause false positive results.
Leukocyte: The test result may not always be consistent with the leukocyte cell number by the microscopic examination. Strong oxidizing agents such as chlorine bleach and formaldehyde may cause positive reactions. Decreased results may be seen with elevated glucose (>1500mg /dl), high specific gravity, oxalic acid and high level of albumin(>1000mg/dL). Drugs causing decreased or false negative results include tetracycline, captopril. Substance that color urine, such as a nitrofurantoin, riboflavin, selenium and bilirubin, may cause false positive results.
Microalbumin: The following substances may cause false positive results; a large amount of hemoglobin(≥5mg/dl), visibly bloody urine, highly alkaline urine(pH>9), disinfectant including quaternary ammonium compound. Substances that cause abnormal urine color, such as drug containing nitrofurantoin, riboflavin may affect the results (false positives).
Creatinine: Nitrofurantoin(≥200mg/L), Riboflavin(≥50mg/L) and a large amount of hemoglobin(≥5mg/dl) cause false positive results. Visibly dark brown color urine may affect the results (false positives). Substances that cause abnormal urine color, such as drug containing nitrofurantoin, riboflavin may affect the results (false positives).
Microalbumin to Creatinine Ratio: A low microalbumin result(10mg/L) in combination with strongly diluted urine (creatinine result of 10mg/dl) could indicate a microalbumin concentration below the sensitivity limit. In that case, consider testing a new specimen, preferably a first morning collection, for greater confidence in the result.
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f. Method Comparison study
The method comparison study was conducted at three clinical sites with a total of 867 samples. The results from the DUS R-50S urine chemistry system (DUS R-50S instrument, DUS10 and DUS2AC reagent strips) was compared to the predicate device (Siemens Clinitek Status + urine chemistry instrument using Multistix 10SG and CLINITEK Microalbumin 2 test strips). The results of the method comparison study for combined sites are shown in the tables below:
| URO (Total) | GLU (Total) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Predicate device(mg/dl) | Predicate device(mg/dl) | |||||||||||
| 8 | 3 | 41 | 2000 | 24 | ||||||||
| 4 | 2 | 86 | 1000 | 1 | 41 | |||||||
| New device(mg/dl) | 2 | 115 | 1 | New device(mg/dl) | 500 | 2 | 59 | |||||
| 1 | 84 | 250 | 1 | 71 | 3 | |||||||
| Norm | 535 | 100 | 71 | |||||||||
| Norm | 1 | 2 | 4 | 8 | NEG | 594 | ||||||
| Total | 535 | 84 | 117 | 90 | 41 | Total | 594 | 72 | 73 | 63 | 41 | 24 |
| Exact agreement | 100% | 100% | 98% | 96% | 100% | Exact agreement | 100% | 99% | 97% | 94% | 100% | 100% |
| Within One Block | 100% | 100% | 100% | 100% | 100% | Within One Block | 100% | 100% | 100% | 100% | 100% | 100% |
| BIL (Total) | KET (Total) | |||||||||||
| Predicate device(mg/dl) | Predicate device(mg/dl) | 9 | ||||||||||
| 4 | 46 | 160 | ||||||||||
| 2 | 4 | 87 | 1 | 80 | 3 | 39 | ||||||
| New device(mg/dl) | 1 | 82 | 3 | New device(mg/dl) | 40 | 60 | ||||||
| NEG | 644 | 15 | 86 | 1 | ||||||||
| NEG | 1 | 2 | 4 | 5 | 60 | 7 | ||||||
| Total | 644 | 86 | 90 | 47 | NEG | 602 | ||||||
| Exact agreement | 100% | 95% | 97% | 98% | Total | 602 | 60 | 93 | 64 | 39 | 9 | |
| Within One Block | 100% | 100% | 100% | 100% | Exact agreement | 100% | 100% | 92% | 94% | 100% | 100% | |
| Within One Block | 100% | 100% | 100% | 100% | 100% | 100% | ||||||
| BLD (Total) | PRO(Total) | |||||||||||
| Predicate device(RBC/ul) | Predicate device(mg/dl) | |||||||||||
| 200 | 4 | 159 | 1000 | 1 | 17 | |||||||
| 80 | 8 | 150 | 1 | 300 | 4 | 51 | ||||||
| New device(RBC/ul) | 25 | 7 | 145 | 5 | 100 | 5 | 104 | |||||
| 10 | 159 | 1 | 30 | 4 | 125 | 1 | ||||||
| NEG | 228 | 15 | 133 | 2 | ||||||||
| NEG | 10 | 25 | 80 | 200 | NEG | 419 | ||||||
| Total | 228 | 166 | 154 | 159 | 160 | NEG | 15 | 30 | 100 | 300 | 1000 | |
| Exact agreement | 100% | 96% | 94% | 94% | 99% | Total | 419 | 137 | 133 | 109 | 52 | 17 |
| Exact agreement | 100% | 97% | 95% | 95% | 98% | 100% |
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| NIT (Total) | Predicate device | LEU (Total) | Predicate device(WBC/ul) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| New device | Pos | 311 | 500 | 2 | 108 | |||||||
| Trace | 125 | 4 | New device (WBClul) | 125 | 3 | 136 | 6 | |||||
| NEG | 427 | 70 | 122 | 4 | ||||||||
| NEG | Trace | Pos | 15 | 105 | 2 | |||||||
| 427 | 125 | 315 | NEG | 379 | ||||||||
| Total | 427 | 125 | 315 | Total | NEG | 15 | 70 | 125 | 500 | |||
| Exact agreement | 100% | 100% | 99% | Exact agreement | 379 | 105 | 127 | 142 | 114 | |||
| Within One Block | 100% | 100% | 100% | Within One Block | 100% | 100% | 96% | 96% | 95% | |||
| PH (Total) | Predicate device | |||||||||||
| 8.5 | 5 | 42 | ||||||||||
| 8 | 5 | 103 | ||||||||||
| 7.5 | 7 | 106 | 3 | |||||||||
| 7 | 3 | 151 | 5 | |||||||||
| New device | 6.5 | 5 | 182 | 2 | ||||||||
| 6 | 1 | 143 | 7 | |||||||||
| 5 | 91 | 6 | ||||||||||
| 5 | 6 | 6.5 | 7 | 7.5 | 8 | 8.5 | ||||||
| Total | 92 | 154 | 192 | 160 | 116 | 111 | 42 | |||||
| Exact agreement | 99% | 93% | 95% | 94% | 91% | 93% | 100% | |||||
| Within One Block | 100% | 100% | 100% | 100% | 100% | 100% | 100% | |||||
| SG(Total) | Predicate device | |||||||||||
| 1.030 | 5 | 82 | ||||||||||
| 1.025 | 5 | 107 | ||||||||||
| 1.020 | 6 | 167 | 2 | |||||||||
| New device | 1.015 | 5 | 166 | 7 | ||||||||
| 1.010 | 5 | 147 | 5 | |||||||||
| 1.005 | 104 | 4 | ||||||||||
| 1.000 | 50 | |||||||||||
| 1.000 | 1.005 | 1.010 | 1.015 | 1.020 | 1.025 | 1.030 | ||||||
| Total | 50 | 109 | 156 | 177 | 179 | 114 | 82 | |||||
| Exact agreement | 100% | 95% | 94% | 94% | 93% | 94% | 100% | |||||
| Within One Block | 100% | 100% | 100% | 100% | 100% | 100% |
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| CRE(Total) | MA (Total) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| New device(mg/dl) | 300 | 200 | 100 | 50 | 10 | Predicate device(mg/dl) | New device(mg/dl) | Predicate device(mg/L) | |||
| 90 | 7 | 15 | 445 | ||||||||
| 7 | 191 11 | 8 | 3 98 3 | ||||||||
| 9 198 9 | 3 | 72 8 | |||||||||
| 151 6 | 1 | 238 | |||||||||
| 1 3 8 15 | |||||||||||
| 10 | 50 | 100 | 200 | 300 | Total | Total | |||||
| 90 | 160 | 211 | 207 | 199 | 238 | 75 | 106 448 | ||||
| 100% | 94% | 94% | 92% | 94% | Exact agreement | Exact agreement | 100% 96% 92% 99% | ||||
| 100% | 100% | 100% | 100% | 100% | Within One Block | Within One Block | 100% 100% 100% 100% |
All of the coefficient of correlation estimated among (MultiStix 10SG vs DUS10 / CLINITEK Microalbumin 2 Vs DUS 2AC) is statistically significant at 1% level. A comparison results between DUS R-50S and CLINITEK Status urinalysis analyzer revealed a very high concordance of between 90-100%. It results were obtained by 867 samples at 3 hospitals.
The majority of analysis display 90-100 % concordance over all blocks on comparing the results of primary diagnosis. When the results, which fall between neighboring blocks, are taken into account, concordance increases to around 95-100%.
| Analyte | Exact agreement (%) | Within one block (%) |
|---|---|---|
| Urobilinogen | 99.3 | 100 |
| Glucose | 99.2 | 100 |
| Bilirubin | 99 | 100 |
| Ketones | 98.7 | 100 |
| Blood | 97 | 100 |
| Protein | 98 | 100 |
| Nitrite | 99.5 | 100 |
| Leukocytes | 98 | 100 |
| pH | 94.3 | 100 |
| Specific Gravity | 94.9 | 100 |
| Creatinine | 94.3 | 100 |
| Microalbumin | 98.4 | 100 |
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G. Expected values/Reference range:
Urobilinogen: The normal urobilinogen range is 0.1 to 1.0 Ehrlich unit /dl. If results exceed the concentration of 2.0 mg/dl, the patient and the urine specimen should be evaluated further.
Glucose: The kidney normally excretes small amounts of glucose. Concentrations of 100mg/dl may be considered as abnormal if found consistently.
Bilirubin: Normally no bilirubin is detectable in urine by even the most sensitive methods. Even trace amounts of bilirubin are sufficiently abnormal to require further investigation.
Ketones: Ketone bodies should not be detected in normal urine specimens with this reagent.
pH: Urine values generally range from pH 4.5 - 8.
Blood: Normally, no hemoglobin is detectable in urine. When hemoglobin appears in urine it may indicate kidney disease or a urinary tract disorder. Blood may often be found in the urine of menstruating females.
Specific Gravity (SG): The normal SG of urine ranges from 1.001 to 1.035.
Protein: Normal urine specimens ordinarily contain some protein (<20mg/dL) therefore only persistent elevated levels of urine protein indicate kidney or urinary tract disease. The persistent results of trace level or over indicate significance proteinuria and thus further clinical testing is needed to evaluate the significant of results.
Nitrite: Normally no nitrite is detectable in urine.
Leukocyte: Normally no leukocytes are detectable in urine.
Microalbumin: Normal albumin excretion in urine is under 30 mg/day.
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Microalbuminuria is indicated with results of > 30 mg/day.
Creatinine: The urine of healthy individuals contains creatinine. Generally, healthy individuals excrete 1g creatinine per day. Very low creatinine results can be caused by adulteration of the urine specimen or by severe renal failure.
Microalbumin to Creatinine Ratio: Microalbumin is normally present in urine at concentrations of less than 30mg albumin/g creatinine. Microalbuminuria is indicated
-Levey AS, Coresh J, Balk E, et al. National Kidney Foundation practice guidelines for chronic kidney disease: evaluation, classification, stratification. Ann Intern Med. 139:137-147; 2003
Conclusion
DUS R-50S (Urine Chemistry System) has the same device characteristics as the predicate device. The results of the testing show that the new device is substantially equivalent to the predicate device.
§ 862.1340 Urinary glucose (nonquantitative) test system.
(a)
Identification. A urinary glucose (nonquantitative) test system is a device intended to measure glucosuria (glucose in urine). Urinary glucose (nonquantitative) measurements are used in the diagnosis and treatment of carbohydrate metabolism disorders including diabetes mellitus, hypoglycemia, and hyperglycemia.(b)
Classification. Class II.