. Author manuscript; available in PMC: 2015 Dec 1.

Published in final edited form as: Addict Behav. 2014 Jun 18;39(12):1695–1700. doi: 10.1016/j.addbeh.2014.06.002

Table 4. Classification accuracy when identifying US adolescents who go on to experiment with smoking and those who become established smokers. Included are the susceptibility, curiosity, and an Enhanced Susceptibility Index which combined the two.

Baseline	Sensitivity¹	Specificity²	PPV³
Experiment with smoking (328/878)
Original Susceptibility Index	37.2%	82.2%	55.5%
Enhanced Susceptibility Index	51.5%	72.4%	52.8%
Established Smoking (97/878)
Original Susceptibility Index	40.2%	76.8%	17.7%
Enhanced Susceptibility Index	54.6%	65.7%	16.6%

Sensitivity: Percent of young adult experimenters identified as “At Risk” at age 10-13.

Specificity: Percent of young adult never smokers identified as “committed never smokers” at age 10-13 years.

Positive Predictive Value: Percent identified as ‘At Risk’ who experimented