Previous studies have also reported significantly higher rates of cigarette smoking among those who use ST products relative to those who do not use ST (Tomar, Alpert, & Connolly, 2010). A considerable body of research has established the increased odds of cigarette smoking among those with histories of anxiety and depression (Grant et al., 2004; Wilhelm et al., 2006; Ziedonis most et al., 2008). Although studies examining ST use and psychiatric disorders are sparse, these associations appear weaker and less reliable than those observed in cigarette smoking (Goodwin et al., 2008). Consistent with other populations (Centers for Disease Control and Prevention, 2006; Howard-Pitney & Winkleby, 2002; Marcus et al., 1989; Nelson et al., 2006), males in both tribes were significantly more likely than females to use ST products.

The observation that 40% of women in the Northern Plains and 31% in the Southwest were classified as lifetime ST users is high. Among U.S. women, the percentage of current users of any tobacco product (cigarettes or ST) is the highest among American Indian/Alaska Natives (37.9%), followed by Native Hawaiians/Pacific Islanders (27%), Whites (26.6%), Blacks (25.4%), Hispanics (18.2%), and Asians (8.4%). High rates of ST use among American Indian women may be partially reflective of the cultural acceptance of tobacco and use of various tobacco products in ceremonial functions (Henderson, Jacobsen, Beals, & the AI-SUPERPFP Team, 2005; Hodge & Struthers, 2006). Further assessment of gender-specific attitudes and beliefs about tobacco use may help clarify additional reasons that underlie differential consumption rates across racial/ethnic groups.

In contrast to other studies, including those with American Indians and Alaska Natives (Redwood et al., 2010), education level did not differentiate users from nonusers in either tribe. Age was the only demographic characteristic associated with ST use that differed between the tribes. Users were more likely to be younger in the Northern Plains, which is a common pattern among lifetime (Bell et al., 2009; Howard-Pitney & Winkleby, 2002) and current ST users (Marcus et al., 1989; Nelson et al., 2006; Redwood et al., 2010). In contrast, lifetime ST use was associated with older age among those residing in the Southwest.

Interestingly, a previous study on correlates of cigarette smoking in the AI-SUPERPFP found that current smokers in the Southwest tended to be younger than nonsmokers, yet no age differences were found between smokers and nonsmokers in the Northern Plains (Henderson et al., 2005). It is unclear if age by tribe differences in lifetime ST use and cigarette smoking represents a meaningful finding or if these patterns can be replicated Dacomitinib in other American Indian cohorts. The tribes may vary in terms of age specific or generational beliefs and attitudes about different modes of tobacco administration.