Validation Self-reported of Drug Use, Using Biologic Markers (pilot phase of Azar cohort study)

Abstract

Objective: To assess the validation of self-reported drug use in people aged 35 and up in a pilot phase of a population base cohort study. Method: All adults over 35 years in Khamene city in East Azarbaijan province were recruited for the pilot phase of Azar cohort; a state level of a nationwide PERSIAN cohort study and completed a questionnaire and provided biological samples. Information about the history and duration of smoking tobacco, using drug and medication were obtained by physician. Validity of the drug use was assessed by comparing the questionnaire response with three urine strip test for detection of morphine, amphetamine and methamphetamine for 259 random selected subjects. Results: Prevalence of drug use according to self-report was 3%. One step drug test as the gold standard for use of drug self-reported had a sensitivity (95% confidence interval) and specificity 40.7% (27.6%-55.0%), 98.7% (96.2%-99.7%) respectively. All participant who had positive self-report were male, however in urine analysis drug test was positive for 7 out of 68 randomly selected women. Conclusion: The validity of self-reported drug use in this population was low and self-reported use of drug should be used with caution in this population. It is recommended to use alternative techniques audio computer-assisted self-interviewing in order to improve the validity of data using self-report procedure.