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One Step Drug Test:  Marijuana (Page 2)

1-Panel - THC
One Step Marijuana Test Device

Page 1

Accuracy

A three way side-by-side comparison was conducted using the THC One Step Marijuana Test Device and a leading commercially available THC rapid test. Testing was performed on specimens previously collected from subjects presenting for Drug Screen Testing. Presumptive positive results were confirmed by GC/MS. The following results were tabulated:

Method Other THC Rapid Test Total Results
THC One Step Test Device Results Positive Negative
Positive 140 0 140
Negative 3 157 160
Total Results 143 157 300
% Agreement With Commercial Kit 98% >99% 99%

When compared to the GC/MS lab testing method at the cutoff concentration of 50 ng/ml, the following results were tabulated:

Method GC/MS Total Results
THC One Step Test Device Results Positive Negative
Positive 118 22 140
Negative 4 156 160
Total Results 122 178 300
% Agreement With GC/MS Analysis 97% 88% 91%

When compared to the GC/MS lab testing method at the cutoff concentration of 25 ng/ml, the following results were tabulated:

Method GC/MS Total Results
THC One Step Test Device Results Positive Negative
Positive 135 5 140
Negative 6 154 160
Total Results 141 159 300
% Agreement With GC/MS Analysis 96% 97% 96%

Point of Care Accuracy

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A study was conducted using the same clinical specimens with ten percent (10%) distribution at 25% above and below the 50 ng/ml cutoff at three geographically distinct point of care sites to determine the accuracy of the THC One Step Marijuana Test Device in the hands of point of care user. Forty (40) positive specimens and forty (40) negative specimens were tested on three (3) different lots of each product.

The difference in sensitivity and specificity results obtained by the laboratory professional for the same clinical specimens compared to the results obtained by the point of care (untrained) user was insignificant. At a ninety-five percent (95%) confidence interval, the odds ratio for the point of care user versus the laboratory professional was 1 to 1 for sensitivity and specificity.

Sensitivity

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A drug-free urine pool was spiked with 11-nor-D9-THC-9 COOH at the following concentrations: 75 ng/ml, 62.5 ng/ml, 37.5 ng/ml, 25 ng/ml, and 0 ng/ml. The result demonstrates >99% accuracy at 50% above and 50% below the cutoff concentration. The data are summarized below:

11-nor-D9-THC-9 COOH Concentration (ng/ml) Percent of Cutoff n Visual Result
Negative Positive
0 0% 30 30 0
25 -50% 30 30 0
37.5 -25% 30 12 18
50 Cutoff 30 1 29
62.5 +25% 30 1 29
75 +50% 30 0 30

Precision

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A study was conducted at 3 physician's offices by untrained operators using 3 different lots of product to demonstrate the within run, between run and between operator precision. An identical panel of coded specimens containing, according to GC/MS, no 11-nor-D9-THC-9 COOH, 25% 11-nor-D9-THC-9 COOH above and below the cutoff and 50% 11-nor-D9-THC-9 COOH above and below the 50 ng/ml cutoff was provided to each site. For the specimens below the -25% cutoff concentration, the 3 sites demonstrated 98% agreement with each other. For the -25% to +25% cutoff specimens, the 3 sites demonstrated 83% agreement with each other. For specimens above the +25% cutoff concentration, the 3 sites demonstrated 94% agreement with each other. For all results, the 3 sites were found to have a 91% agreement with each other.

Effect of Urinary Specific Gravity

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Twenty-six (26) urine samples of normal, high, and low specific gravity ranges were spiked with 25 ng/ml and 75 ng/ml of 11-nor-D9-THC-9 COOH, respectively. The THC One Step Marijuana Test Device was tested in duplicate using the twenty-six neat and spiked urine samples. The results demonstrate that varying ranges of urinary specific gravity does not affect the test results.

Effect of Urinary pH

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The pH of an aliquoted negative urine pool was adjusted to a pH range of 5 to 9 in 1 pH unit increments and spiked with 11-nor-D9-THC-9 COOH to 25 ng/ml and 75 ng/ml. The spiked, pH-adjusted urine was tested with the THC One Step Marijuana Test Device in duplicate and interpreted according to the package insert. The results demonstrate that varying ranges of pH does not interfere with the performance of the test.

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