162499 Validity of ACASI self-reports of drug use with on-site urine testing in the general population of Puerto Rico

Wednesday, November 7, 2007: 9:24 AM

Cynthia M. Pérez, PhD , Department of Biostatistics and Epidemiology, University of Puerto Rico, Graduate School of Public Health, San Juan, PR
Erick Suárez, PhD, MS , Department of Biostatistics and Epidemiology, University of Puerto Rico, Graduate School of Public Health, San Juan, PR
Ana P. Ortiz, PhD , Department of Biostatistics and Epidemiology, University of Puerto Rico, Graduate School of Public Health, San Juan, PR
Edmir Marrero, MPH , Department of Biostatistics and Epidemiology, University of Puerto Rico, Graduate School of Public Health, San Juan, PR
Marytere Meléndez, MPH , Department of Biostatistics and Epidemiology, University of Puerto Rico, Graduate School of Public Health, San Juan, PR
Carmen Albizu , Departament of Health Services Administration, University of Puerto Rico, Graduate School of Public Health, San Juan, PR
Samuel R. Friedman, PhD , National Development and Research Institutes, Inc, New York, NY
Hector Colón, PhD , Departamento de Medicina, Universidad Central del Caribe, Bayamon, PR
The extent to which individuals are willing to disclose their use of illicit drugs in general population surveys is still unclear; this is particularly true both for minority populations such as Hispanics and in relation to potential under-reporting of stigmatized behaviors using ACASI. As part of a household survey of hepatitis C in the general population of Puerto Rico, self-reports of illicit drug use were compared with on-site urine toxicology testing. Information on recent use (last three days) and past year and lifetime use was collected using ACASI. On-site urine testing for drug metabolites to detect recent marihuana (last 10 days), cocaine (last 2-4 days) and opiate (last 2-3 days) use was performed prior to the interview. Sensitivity and specificity of self-reports, using the urine test as the standard, were estimated in a sub-sample of 520 adults aged 21-64 years. Prevalence of self-reported recent use was 2.9% for marihuana, 3.1% for cocaine, and 0.8% for heroin. Prevalence based on urine tests was 3.9% for marihuana and cocaine and 1.0% for heroin. Sensitivity for self-reports of recent use was 60% for marihuana, 70% for cocaine and 40% for heroin. Sensitivity increased with reports of use in more remote time periods. Specificity for self-reports of recent use for all drugs was 99.2% or higher, and it decreased with reports of use in more remote time periods. These results suggest that disclosure of marihuana and cocaine lifetime use using ACASI in the general population of Puerto Rico is higher than that for heroin.

Learning Objectives:
1. To assess the prevalence of drug use by urine test and ACASI self-report in the general population of Puerto Rico 2. To evaluate the validity of ACASI self-reports of drug use in the general population of Puerto Rico

Keywords: Drug Use, Methodology

Presenting author's disclosure statement:

Any relevant financial relationships? No
Any institutionally-contracted trials related to this submission?

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.