of cigars or cigarellos (Sterling et al., 2016)), hookah (# of hits), pipes (# of hits), nicotine replacement (# of doses); visual aids will be provided for all nicotine categories. Follow-up questions on the lifetime and 6-month TLFB will assess whether youth typically use cigarettes with flavoring (Biswas et al., 2016; Alsharari et al., 2015; Nonnemaker et al., 2013). Additional follow-up questions will determine typical amount of liquid used in e-cigarette, typical dose of nicotine, how often their e-cigarettes contain nicotine, and type of cartridge (disposable versus re-chargeable), which may impact total nicotine exposure (Breland et al., 2016, Breland et al., 2014; Lopez et al., 2016).4.Cocaine or crack cocaine. Cocaine and crack cocaine will be measured in total occasions (max use in mg). Follow-up questions on the TLFB ask about typical route of administration (smoking, oral ingestion, intranasal/snorting, injecting subcutaneous, injecting intramuscular, injecting intravenous), how often they inject cocaine, how often they use clean needles, and how often they smoke it (Nuijten et al., 2016; Conti et al., 2014; Novak and Kral, 2011). Pictures of various types of cocaine products and typical dosing are provided.5.Cathinones (“cathinones such as bath salts, drone, M-cat, MDVP or meph”). The unit of measurement is
