Protection motivation theory and cigarette smoking among vocational high school students in China: a cusp catastrophe modeling analysis

Table 2 Cusp catastrophe modeling of reported days of smoking during the 30-day period prior to the survey, including the survey day

Model variables	Asymmetry	Bifurcation	Days smoked
Estimated parameter
Intercept	α ₀ = −1.4314**	β ₀ = 2.9907**	w ₀ = −3.4534**
Threat appraisal	α ₁ = 0.2168**	β ₁ = −0.0010	w ₁ = 1.4228**
Coping appraisal	α ₂ = −0.0010	β ₂ = 0.1517
Model fit	Cusp	Logistic	Linear
AIC	736	1318	1332
BIC	770	1348	1349
R ²	0.81	0.07	0.04
Estimated parameter
Intercept	α ₀ = 0.3515	β ₀ = 2.7717**	w ₀ = −3.4748**
Threat appraisal	α ₁ = 0.1987**	β ₁ = −0.0288	w ₁ = 1.4217**
Coping appraisal	α ₂ = −0.0466	β ₂ = 0.1760*
Gender (if female)	a ₃ = 1.3050**
Grade	a ₄ = 0.0120
Model fit	Cusp	Logistic	Linear
AIC	622	1208	1233
BIC	665	1246	1258
R ²	0.82	0.25	0.21

ISSN: 2397-0642