title: Patterns of cigarette smoking initiation in two culturally distinct American Indian tribes.
abstract: OBJECTIVE
  To better understand patterns of initiation among American Indians we examined age-related patterns of smoking initiation during adolescence and young adulthood in 2 American Indian tribes.
  
  
  METHODS
  We used log-rank comparison and a Cox proportional hazard regression model to analyze data from a population-based study of Southwest and Northern Plains American Indians aged 18 to 95 years who initiated smoking by age 18 years or younger.
  
  
  RESULTS
  The cumulative incidence of smoking initiation was much higher among the Northern Plains Indians (47%) than among the Southwest Indians (28%; P < .01). In the Southwest, men were more likely than women to initiate smoking at a younger age (P < .01); there was no such difference in the Northern Plains sample. Northern Plains men and women in more recent birth cohorts initiated smoking at an earlier age than did those born in older birth cohorts. Southwest men and women differed in the pattern of smoking initiation across birth cohorts as evidenced by the significant test for interaction (P = .01).
  
  
  CONCLUSIONS
  Our findings underscore the need to implement tobacco prevention and control measures within American Indian communities.
authors.affiliation: Black Hills Center for American Indian Health, 701 St. Joseph Street, Suite 204, Rapid City, SD 57701, USA. pnhenderson@bhcaih.org
authors.forename: Patricia
authors.initials: P
authors.lastname: Nez Henderson
authors.forename: Shalini
authors.initials: S
authors.lastname: Kanekar
authors.forename: Yang
authors.initials: Y
authors.lastname: Wen
authors.forename: Dedra
authors.initials: D
authors.lastname: Buchwald
authors.forename: Jack
authors.initials: J
authors.lastname: Goldberg
authors.forename: Won
authors.initials: W
authors.lastname: Choi
authors.forename: Kolawole S
authors.initials: KS
authors.lastname: Okuyemi
authors.forename: Jasjit
authors.initials: J
authors.lastname: Ahluwalia
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Henderson
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D000328:Adult; D017677:Age Distribution; D001130:Arizona / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007198:Indians, North American; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D017678:Sex Distribution; D012907:Smoking / Q000208:ethnology*; D013023:South Dakota / Q000453:epidemiology; D055815:Young Adult