233410 Measuring tobacco use in a prison population

Monday, November 8, 2010 : 10:30 AM - 10:50 AM

Ross Kauffman, PhD , School of Nursing, Indiana University, Indianapolis, IN
Background: Widespread tobacco use and high interest in quitting make prisons an ideal environment for smoking cessation interventions, however little has been done to assist prisoners in their efforts to quit. Measuring tobacco use is central to tobacco research, yet there has been only one published examination of tobacco use measures among prisoners. Methods: Personal interviews were conducted with 200 male prisoners. Four measures of tobacco use were collected: self-report, carbon monoxide (CO) breath test, salivary cotinine measured by enzyme immunoassay (EIA), and salivary cotinine measured by liquid chromatography tandem mass spectrometry (LC/MS/MS). Calculated sensitivity and specificity of the tests were compared using first self-reports, then LC/MS/MS as the gold standard. Optimum cutpoints for continuous measures were selected to maximize the Youden index. Results: With self-reported tobacco use as the standard, all tests showed excellent discrimination (CO: cut point ≥ 4 ppm, sensitivity = 88.3%, specificity = 94.9%; EIA: cut point ≥ 10 ng/ml, sensitivity = 92.2%, specificity = 94.3%; LC/MS/MS: cut point ≥ 9 ng/ml, sensitivity = 98.6%, specificity = 97.8%). Using LC/MS/MS as the gold standard produced similar, but not identical, results (CO: cut point ≥ 4 ppm, sensitivity = 85.4%, specificity = 91.7%; EIA: cut point ≥ 10 ng/ml, sensitivity = 94.2%, specificity = 100.0%;self-report: sensitivity = 98.5%, specificity = 88.9%). Conclusions: In the absence of a perfect predictor of the outcome of interest, investigators must consider how use of an imperfect "gold standard" may impact estimates of test performance.

Learning Areas:
Biostatistics, economics
Chronic disease management and prevention
Public health or related research

Learning Objectives:
1. Articulate the advantages and disadvantages of various biomarkers in assessing tobacco use in prison populations. 2. Describe strategies for estimating test performance in the absence of a perfect “gold standard.”

Keywords: Methodology, Tobacco

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am qualified to be an abstract Author on the content I am responsible for because of my years of research in public health and in tobacco control areas.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.