Table 3.

The threshold effect of NHHR on suicidal ideation stratified by smoking status was analyzed using a two-part linear regression model

	Smoking status
	Yes	No
Fitting by standard linear model
OR (95% CI)	1.10 (0.96, 1.26)	1.08 (1.00, 1.16)
P-value	0.1596	0.0502
Fitting by two-piecewise linear model
Breakpoint (K)	2.42	7.80
OR1(<K)	2.03 (0.83, 4.97) 0.1211	1.14 (1.04, 1.25) 0.0054
OR2(>K)	1.04 (0.87, 1.24) 0.6749	0.47 (0.11, 2.09) 0.3236
Logarithmic likelihood ratio test P-value	0.150	0.028

Age, gender, race, marital status, education level, BMI, income-to-poverty ratio, smoking status, diabetes, hypertension, physical activity, and dietary cholesterol were adjusted. 95% CI, 95% confidence interval; OR, odds ratio