Table 2.

Associations of AFB, and ALB with the risk of arthritis

	Model 1		Model 2		Model 3
	OR (95%CI)	P for trend	OR (95%CI)	P for trend	OR (95%CI)	P for trend
AFB (years)		< 0.001		0.051		0.229
≤ 23	1.00		1.00		1.00
24–26	0.56 (0.43, 0.74)***		0.69 (0.53, 0.91)*		0.81 (0.79, 0.99)*
27–29	0.61 (0.51, 0.74)***		0.77 (0.64, 0.94)*		0.88 (0.62, 1.08)
30–32	0.68 (0.48, 0.86)***		0.81 (0.73, 0.96)*		0.95 (0.78, 1.16)
33–35	0.70 (0.64, 0.79)***		0.83 (0.74, 0.97)*		0.99 (0.86, 1.14)
≥ 36	0.71 (0.62, 0.81)***		0.85 (0.58, 1.17)		1.03 (0.71, 1.47)
ALB (years)		< 0.001		0.281		0.457
≤ 23	1.00		1.00		1.00
25–29	0.82 (0.74, 0.91)***		0.90 (0.81, 1.00)		0.94 (0.84, 1.05)
30–34	0.67 (0.60, 0.75)***		0.76 (0.68, 0.85)***		0.84 (0.75, 0.94)**
35–39	0.62 (0.55, 0.70)***		0.70 (0.62, 0.79)***		0.81 (0.72, 0.93**
≥ 40	0.48 (0.40, 0.58)***		0.52 (0.43, 0.63)***		0.65 (0.53, 0.78)***

Abbreviations: AFB age at first birth, ALB age at last birth, OR odds ratio, CI confidence interval

Model 1: age and race/ethnicity

Model 2: model 1 variables plus education level, marital status, family poverty-income ratio, hypertension, diabetes mellitus, smoker, alcohol user

Model 3 was adjusted for model 2 variables plus body mass index, waist circumference, systolic blood pressure, diastolic blood pressure, mean energy intake, hemoglobin, fast glucose, alkaline phosphatase, total protein, sodium, phosphorus, calcium, potassium, menopause status, oral contraceptive use, use female hormones, had a hysterectomy, both ovaries removed, blood urea nitrogen, uric acid, serum creatinine, estimated glomerular filtration rate, total cholesterol, triglyceride, high-density lipoprotein-cholesterol, age at menarche, age at menopause, and fertile lifespan

^*P < 0.05, **P < 0.01, ***P < 0.001