Should anyone be riding to glory on the now-descending limb of the crack-cocaine epidemic curve in the United States?

Background: Many pre-clinical and clinical researchers do not appreciate the recent decline in United States (US) population-level incidence of crack-cocaine smoking. At present, no more than about 200 young people start using crack-cocaine each day. Ten years ago, the corresponding estimated daily rate was 1000. This short communication looks into these trends, surrounding evidence on this important public health topic, and checks whether duration-reducing treatment interventions might be responsible, versus selected alternatives. Methods: Via analyses of standardized computer-assisted self-interview data from the US National Surveys on Drug Use and Health (NSDUH, 2002-2011; n > 500,000), we evaluated change in incidence estimates, perceived difficulty to acquire crack, risk of using cocaine, treatment entries, and persistence once crack use has started. Results: We draw attention to a marked overall decline in year-specific incidence rates for crack-cocaine smoking from 2002 to 2011, especially 2007-2011. There is some variation in estimates of difficulty to acquire crack (p < 0.001) and observed risk of using cocaine among 'at risk' susceptibles (p < 0.001), but no appreciable shifts in duration of crack smoking among active users (p > 0.05) or in proportion of crack users receiving treatment (p > 0.05). Conclusions: Changing epidemiology of crack-cocaine smoking may rest largely on reductions in newly incident use with no major direct effects due to US cocaine treatment, incarceration, or interdiction. Concurrently, we see quite modest declines in survey-based estimates of cocaine-attributed perceived risk and cocaine availability. As such, we posit that no specific US agency should claim it is 'riding to glory' on the descending limb of this epidemic curve. (C) 2014 Elsevier Ireland Ltd. All rights reserved.