Table 7

Approximate sample sizes for youth smoking prevalence results

Location Data source Grade 1985 1986 1987 1988 1989 1990 1991 1993 1995 1997 1998 1999
VermontFlynn et al 7 8 6–12545854585458545854584670
CaliforniaMonitoring the Future66 8600636708
Monitoring the Future66 10490581508
MassachusettsMYRBS72 10 or 1283010409961104
Northeast regionMonitoring the Future65 10763868868789
Monitoring the Future65 12711737868658
FloridaFYTS75 838363634
FYTS75 10 or 1220291828
South regionMonitoring the Future65 817371605
Monitoring the Future65 1013681237
Monitoring the Future65 1215001289
MinnesotaMurray et al 52 935803926
WisconsinMurrayet al 52 935763190
CanadaHealth Canada, in Pechmann et al 50 15–19 year olds303830383038303830383038
USAMonitoring the Future65 8481646054895
Monitoring the Future65 10402644744079
  • Monitoring the Future sample sizes reflect the reported weighted n's divided by a 3.8 design effect. We did this to align our analyses with standard Monitoring the Future analyses (telephone conversation with Tim Perry, Monitoring the Future, February 2000).

  • The sample sizes associated with the California specific Monitoring the Future results were not available and so we estimated them. Specifically, we calculated the sample size for each grade as 69% of the reported western region sample.

  • The MYRBS and FYTS grade specific sample sizes were not available and so we estimated them. Specifically, we calculated them as percentages of the reported middle and high school samples as follows: grade 8 = 33% of middle school sample, grade 10 = 25% of high school sample, grade 12 = 25% of high school sample.