1. to 4. You are subjected to a blood test for illegal drugs, but you are allowed to specify the experimental design of the test. Mark the ideal design feature(s) from the following list that would help prevent each of the following problems. More than one answer may apply.

Ideal Data Features

(A) explicit protocol
(B) standards
(C) randomization
(D) replication
(E) blind

1. Problem: use of post hoc criteria in deciding whether the results are positive.

2. Problem: accidentally mixing your sample with someone else's.

3. Problem: using the wrong baseline (external reference point) in establishing whether a test result constitutes evidence of drug use.

4. Problem: someone deliberately tampering with your sample because they want to "get" you.

5. to 7. You apply for a job as a sales clerk at Super Computers, and are given a urine test for illegal drugs. You are told that Drug Test, Inc., actually performs the laboratory analysis of the urine samples collected by Super Computers. However, your interviewer volunteers no further information. Since you don't use illegal drugs, you are surprised when your urine test comes back positive, and Super Computers refuses to hire you. You want to determine how this positive test result could have happened. For each of the models listed below, indicate which of the following questions should be asked to help determine whether the model is correct or not. That is, mark a question only if a truthful answer to it could produce information that is directly relevant to deciding if a particular model is correct.

Questions

(A) How many test tubes of my urine did Super Computers send to Drug Test, Inc.?

(B) When the test tubes containing my urine were sent to Drug Test, Inc. were they labeled with my name, or only with a code? If they were labeled with a code, which Super Computer employees had access to the sheet showing my code and name?

(C) Are the Super Computers job applicants who are tested chosen randomly?

(D) Does Drug Test, Inc. have written laboratory procedures for preventing samples from getting mixed up?

(E) Did Super Computers send a standard, known to be drug-free, to Drug Test, Inc. with my urine sample?

(F) Did Super Computers send a standard, known to contain illegal drugs, to Drug Test, Inc. with my urine sample?

5. Model: There are no procedures for determining if Drug Test, Inc.'s laboratory practices produce the same result for two test tubes containing the same urine sample.

6. Model: Some legal drugs cause a false positive in a urine test, but do not cause a false positive in a blood test.

7. Model: Drug Test, Inc. deliberately misreported the results of my urine test, after receiving a phone call from a Super Computers sales manager, saying that he did not want to hire me.

8. and 9. Each of items (A) through (J) describes a feature of Department of Transportation drug tests.

(A) The details of the drug testing rules are presented in the Federal Register 49 CFR PART 40 and described in a 100+ page pamphlet "Guidelines for Implementing the FHWA anti-drug program."

(B) Each manager whose employees are tested is required to include 3 known blank samples (lacking drugs) for every 100 unknowns; managers with more than 2000 drivers must also include some samples known to contain drugs.

(C) The samples known to be positive are labeled so that they appear to the testing lab to be ordinary samples.

(D) Split sample collection involves the partitioning of the original sample into two vials.

(E) The rules specify that any retesting is to be done by a different laboratory than did the original test.

(F) The person being tested must request the retest.

(G) The regulations require that any driver involved in an accident be tested for drugs and alcohol.

(H) When a sample is sent to the laboratory for testing, it is labeled with a code, rather than the name of the person being tested.

(I) All test results are sent to an independent 3rd party (the medical review officer) before being returned to the office originating the test.

(J) The testing laboratory tests all samples with an initial and rapid screen; only positive samples are analyzed more comprehensively.

8. Which feature(s) demonstrate(s) that DOT drug tests are done blind?

9. Which feature(s) demonstrate(s) that the choice of who is tested (among all employees) is not made completely at random?

 
Table of contents Chapter 9. Drug Testing Protocols Ensure Data Accuracy
Copyright 1996, 1997 Craig M. Pease and James J. Bull. All rights reserved.
301C@bull.zo.utexas.edu