Objectives
Substance use may influence study results in human subjects research. This study aims to report the concordance between self‐report and biochemical assessments of substance use and test the effect of methods to reduce false reports of abstinence in trauma‐exposed women participating in a research study.
Methods
In this pilot study, substance use was assessed during telephone prescreening and via self‐report and biochemical verification (i.e., urine toxicology and alcohol breathalyzer tests) at an in‐person evaluation. Due to the high number of participants who tested positive for substances despite self‐reporting abstinence during prescreening, study procedures were modified to disincentivize false self‐reports of substance use two thirds of the way through recruitment. New potential participants were explicitly informed during prescreening and informed consent that a positive drug or alcohol test during screening would result in exclusion from the study and withholding of payment.
Results
Prior to modifying study methods, 20% of participants who had reported abstinence during the telephone prescreen had a positive substance use test at the in‐person visit. Modifying study procedures resulted in an 81% decrease in positive substance use assessments.
Conclusions
Adoption of this methodology may decrease inadvertent confounding of clinical research outcomes by undetected and/or misreported substance use.