How did you know you got the right pill? Prescription opioid identification and measurement error in the abuse deterrent formulation era

From December 2010 to January 2014, 57 percent of ASI-MV respondents reporting any
OC/OP indicated OC use. In multivariable analyses, OC reporting was greater among
Black users (p 0.05) who were not primarily opioid abusers (p 0.10), and increased
over time among people using opioids as prescribed (p 0.01). Early post-reformulation,
OC use was endorsed by users aged 21–34 and people having recently initiated heroin,
but trends reversed over time (p 0.05). Online forum users reporting NMPU also reported
obtaining OC during fall 2013 (18.5%). Qualitative analyses indicated that source
of drug identification knowledge, trust and relationship with their drug source, context
in which the drug was obtained, and motivations for NMPU contributed to misidentification
of OC/OP and other products. “Counterfeits” were noted as a common element of the
illicit market and may partially explain endorsement rates, especially early post-reformulation,
when street prices for the old formulation (and counterfeits) were high. Cognitive
factors such as lacking images (front, back, dosage) and labels, confusion between
generics and branded products, and literacy level suggest item-level modifications.