Table 9.

Smoking cessation duration as categorical variables to analyze the relationship between smoking cessation and depression in adults (n = 13,651) in NHANES (2005–2018).

	OR (95%CI), P-value
	Model 1	Model 2	Model 3
Smoking cessation duration
Q0	1	1	1
Q1	0.53 (0.44–0.64) < 0.001	0.52 (0.42–0.63) < 0.001	0.63 (0.51–0.78) < 0.001
Q2	0.39 (0.30–0.51) < 0.001	0.37 (0.27–0.49) < 0.001	0.48 (0.36–0.65) < 0.001
Q3	0.39 (0.29–0.51) < 0.001	0.36 (0.27–0.48) < 0.001	0.55 (0.40–0.75) < 0.001
Q4	0.36 (0.27–0.48) < 0.001	0.35 (0.25–0.49) < 0.001	0.55 (0.39–0.79) < 0.001
P for trend	< 0.001	< 0.001	< 0.001

Model 1: adjust for none. Model 2, adjust for age, gender, BMI, race. Model 3, adjust for age, gender, BMI, race, educational level, marital status, family PIR, diabetes, failing kidneys, heart failure, coronary heart disease, emphysema, chronic bronchitis, cancer or malignancy.

P for trend was calculated by modeling the median value of quit smoking time in each quartile as a continuous variable.

CI, confidence interval; OR, odds ratio.

Q0, not quit smoking (0 days); Q1, 1st quartile of smoking cessation duration (< 5 years); Q2, 2nd quartile of smoking cessation duration (5–15 years); Q3, 3rd quartile of smoking cessation duration (15–29 years); Q4, 4th quartile of smoking cessation duration (>29 years).