An unusual finding in this study was the high severity of the hazardous use criterion relative to the other criteria. While the prevalence of hazardous use was high in this clinical sample compared to general population adult samples, hazardous use had the poorest discrimination for all four substances, the lowest factor loading for cannabis, cocaine and heroin, and the second lowest factor loading for alcohol. Further, there was indication that a substantial proportion of its variance was captured by a dimension other than the general factor. Future work should consider whether this pattern is specific to the present study or more general to substance abuse treatment samples. In particular, since New York City has a widely used public transportation system, and the most common way to meet criteria for hazardous use is by driving after drinking or using drugs (Hasin and Paykin, 1999; Hasin et al., 1999; Keyes and Hasin, 2008), the result for hazardous use should be replicated in cities where patients are more likely to drive as their main method of transportation.
