Table 2.

Results of the weighted univariate logistic regression analysis of factors associated with RA.

Exposure	Statistics	OR (95% CI)
Dietary fiber intake (g/d)	16.99 ± 11.28	0.98 (0.98, 0.99)
Dietary fiber intake tertile
Tertile 1 (<10.9 g/d)	5034 (33.31%)	1.0 (ref)
Tertile 2 (11.0–19.1 g/d)	5036 (33.32%)	0.85 (0.73, 0.99)
Tertile 3 (>19.1 g/d)	5044 (33.37%)	0.73 (0.62, 0.85)
Sex, n (%)
Male	7581 (50.16%)	1.0 (ref)
Female	7533 (49.84%)	1.41 (1.24, 1.60)
Race/ethnicity, n (%)
Non-Hispanic white	5267 (34.85%)	1.0 (ref)
Non-Hispanic black	3764 (24.90%)	1.40 (1.20, 1.63)
Mexican American	2059 (13.62%)	0.85 (0.69, 1.05)
Other race/multiracial	4024 (26.62%)	0.64 (0.54, 0.77)
BMI, n (%)
<24.9	4447 (29.67%)	1.0 (ref)
25–29.9	4885 (32.59%)	1.60 (1.33, 1.92)
≥30	5657 (37.74%)	2.23 (1.88, 2.64)
Age, n (%)
20–59	11,222 (74.25%)	1.0 (ref)
≥60	3892 (25.75%)	4.54 (3.99, 5.16)
Education, n (%)
Less than high school	2822 (18.67%)	1.0 (ref)
High school	3354 (22.19%)	0.73 (0.61, 0.87)
More than high school	8938 (59.14%)	0.50 (0.43, 0.59)
Family PIR, n (%)
<1.2	3737 (27.22%)	1.0 (ref)
≥1.2	9993 (72.78%)	0.59 (0.52, 0.68)
Moderate activities, n (%)
Yes	6621 (43.81%)	1.0 (ref)
No	8493 (56.19%)	0.56 (0.49, 0.63)
Smoking status, n (%)
Never	9131 (60.41%)	1.0 (ref)
Ever	5983 (39.59%)	1.58 (1.39, 1.80)
Drinking alcohol status, n (%)
Never	11,701 (77.42%)	1.0 (ref)
Ever	3413 (22.58%)	0.50 (0.43, 0.59)

Mean ± standard error (SE) for continuous variables, Percentage (%) for categorical variables. P value was calculated via logistic regression analysis.

PIR = the ratio of family income-to poverty, RA = rheumatoid arthritis.