Table 3.

Association between caffeine intake and constipation based on age

Variables	Number	Crude model		Adjusted model
		OR (95% CI)	P	OR (95% CI)	P
Age < 40 years
Q1	1286	Ref		Ref
Q2	1254	1.21 (0.86–1.69)	0.265	1.05 (0.75–1.48)	0.768
Q3	981	0.50 (0.35–0.73)	< 0.001	0.47 (0.31–0.70)	< 0.001
Q4	723	0.89 (0.65–1.23)	0.470	0.86 (0.61–1.19)	0.352
Q5	593	0.67 (0.42–1.08)	0.098	0.68 (0.42–1.10)	0.116
40 years ≤ age < 65 years
Q1	1146	Ref		Ref
Q2	1156	1.02 (0.72–1.44)	0.924	0.89 (0.63–1.26)	0.499
Q3	1197	0.67 (0.47–0.95)	0.026	0.61 (0.43–0.86)	0.006
Q4	1134	0.60 (0.36–0.99)	0.047	0.61 (0.38–0.98)	0.042
Q5	1210	0.65 (0.44–0.96)	0.031	0.67 (0.45–0.99)	0.048
Age ≥ 65 years
Q1	772	Ref		Ref
Q2	688	1.03 (0.69–1.52)	0.889	0.97 (0.63–1.47)	0.868
Q3	681	0.83 (0.58–1.18)	0.291	0.81 (0.56–1.18)	0.263
Q4	596	0.76 (0.47–1.22)	0.248	0.84 (0.52–1.37)	0.486
Q5	399	0.61 (0.35–1.07)	0.084	0.69 (0.39–1.24)	0.207

Abbreviation: OR, odds ratio; CI, confidence interval

Crude model: weighted univariate logistic regression analysis

Adjusted model: weighted multivariable logistic regression analysis adjusted gender, PIR, drinking, depression, BMI, dietary fiber, and moisture