The opioid drug section of the SSADDA contains 23 questions on (1) age of onset, frequency, and intensity of opioid use; (2) route of opioid administration; (3) occurrence of psychosocial and medical consequences of opioid use; (4) attempts to quit opioid use; and (5) opioid treatment history, resulting in 220 variables. A previous study on a subset of the sample used in the present study identified key questions in this section for the purpose of subtyping opioid use and related behaviors based on the apparent clinical utility of the features as discriminators of opioid-use-behavior subtypes (Chan et al., 2011).
