Table 4.

Subgroup analyses of the association between quartiles of riboflavin intake and all-cause mortality.

	Quartiles of Riboflavin Intake
Factors	Q1	Q2	Q3	Q4		p
Age group						0.467
20–39	1.00	0.54 (0.14–2.04)	1.36 (0.28–6.69)	0.57 (0.09–3.70)	0.765
40–59	1.00	0.40 (0.19–0.83)	0.59 (0.31–1.11)	0.51 (0.26–1.03)	0.165
60+	1.00	0.77 (0.61–0.97)	0.76 (0.60–0.95)	0.67 (0.50–0.89)	0.009
Gender						0.776
Men	1.00	0.75 (0.53–1.07)	0.75 (0.53–1.07)	0.60 (0.41–0.88)	0.020
Women	1.00	0.64 (0.47–0.86)	0.73 (0.51–1.03)	0.64 (0.45–0.91)	0.025
Race/ethnicity						0.039
NH White	1.00	0.61 (0.46–0.81)	0.64 (0.49–0.83)	0.53 (0.39–0.70)	<0.001
NH Black	1.00	0.95 (0.60–1.51)	0.98 (0.55–1.73)	1.17 (0.62–2.21)	0.799
Mex American	1.00	0.80 (0.44–1.46)	1.05 (0.47–2.34)	0.73 (0.26–2.06)	0.796
Other	1.00	0.94 (0.39–2.26)	2.10 (0.66–6.70)	1.76 (0.47–6.53)	0.230
Smoking						0.223
Never	1.00	0.64 (0.47–0.85)	0.72 (0.48–1.08)	0.69 (0.45–1.06)	0.164
Former	1.00	0.72 (0.52–1.01)	0.70 (0.46–1.06)	0.58 (0.36–0.95)	0.043
Alcohol drinking (past 12 months)						0.010
No	1.00	1.06 (0.73–1.54)	1.25 (0.82–1.89)	1.16 (0.75–1.78)	0.443
Yes	1.00	0.51 (0.36–0.72)	0.49 (0.35–0.69)	0.39 (0.26–0.58)	<0.001
Missing	1.00	0.67 (0.38–1.18)	1.05 (0.64–1.72)	1.14 (0.57–2.27)	0.586
Current smoker	1.00	0.81 (0.46–1.45)	0.99 (0.57–1.72)	0.71 (0.40–1.28)	0.338
Folate intake (DFE, quartiles)						0.111
Q1–Q2	1.00	0.71 (0.54–0.93)	0.93 (0.67–1.29)	0.71 (0.44–1.16)	0.278
Q3–Q4	1.00	0.48 (0.29–0.80)	0.43 (0.25–0.73)	0.40 (0.24–0.69)	0.047

Model adjusted for age, gender, race, physical activity, education, smoking, alcohol drinking, and intake of energy and fat. Stratification variables were not adjusted in the corresponding model. p from Cox regression analysis of interaction term of the listed variable and riboflavin.