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One Step Drug Test:  Barbiturates (Page 2)

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One Step Barbiturates Test Device

Page 1

Accuracy

A side-by-side comparison was conducted using the BAR One Step Barbiturates Test Device and a commercially available BAR 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 BAR Rapid Test Total Results
BAR One Step Test Device Results Positive Negative
Positive 126 1 127
Negative 0 165 165
Total Results 126 166 292
% Agreement With Commercial Kit >99% 99% >99%

When compared to the GC/MS lab testing method at the cutoff concentration of 300 ng/ml, the following results were tabulated:

Method GC/MS Total Results
BAR One Step Test Device Results Positive Negative
Positive 122 4 126
Negative 10 156 166
Total Results 132 160 292
% Agreement With GC/MS Analysis 92% 98% 95%

Eighty (80) of these samples were also run using the BAR One Step Barbiturates Test Device by an untrained operator at a different site. Based on GC/MS data, the operator obtained a statistically similar Positive Agreement, Negative Agreement and Overall Agreement rate as the laboratory personnel.

Sensitivity

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A drug-free urine pool was spiked with Secobarbital at the following concentrations: 0 ng/ml, 150 ng/ml, 225 ng/ml, 300 ng/ml, 375 ng/ml, 450 ng/ml and 600 ng/ml. The result demonstrates 97% accuracy at 50% above and 50% below the cut- off concentration. The data are summarized below:

Secobarbital Concentration (ng/ml) Percent of Cutoff n Visual Result
Negative Positive
0 0% 30 30 0
150 -50% 30 30 0
225 -25% 30 27 3
300 Cutoff 30 22 8
375 +25% 30 7 23
450 +50% 30 2 28
600 +100% 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 no Secobarbital, 25% Secobarbital above and below the cutoff and 50% Secobarbital above and below the 300 ng/ml cutoff was provided to each site. The following results were tabulated:

Secobarbital Concentration (ng/ml) n Site A Site B Site C
- + - + - +
0 15 15 0 15 0 15 0
150 15 13 2 15 0 15 0
225 15 5 10 7 8 10 5
375 15 2 13 5 10 5 10
450 15 0 15 1 14 1 14

Effect of Urinary Specific Gravity

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Fifteen (15) urine samples with specific gravity ranges from 1.000 to 1.037 were spiked with 150 ng/ml and 450 ng/ml of Secobarbital respectively. The BAR One Step Barbiturates Test Device was tested in duplicate using the fifteen 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 Secobarbital to 150 ng/ml and 450 ng/ml. The spiked, pH-adjusted urine was tested with the BAR One Step Barbiturates Test Device in duplicate. The results demonstrate that varying ranges of pH does not interfere with the performance of the test.

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