Table 2 Logistic regression and subgroup analysis for association of anemia with VB12 status under different DDS

All (N = 2405)

0.61 (0.51–0.73)

<0.001

0.69 (0.57–0.83)

<0.001

0.70 (0.57–0.85)

<0.001

Low DDS group (N = 1252)

0.55 (0.43–0.70)

<0.001

0.59 (0.46–0.76)

<0.001

0.59 (0.45–0.77)

<0.001

DDS≤3(N = 799)

0.55 (0.41–0.75)

<0.001

0.6 (0.44–0.82)

0.002

0.62 (0.44–0.88)

0.007

DDS=4 (N = 453)

0.55 (0.36–0.83)

0.005

0.61 (0.40–0.94)

0.024

0.47 (0.29–0.77)

0.003

High DDS group (N = 1127)

0.72 (0.55–0.94)

0.015

0.85 (0.64–1.12)

0.245

0.88 (0.65–1.19)

0.411

DDS=5 (N = 475)

0.99 (0.67–1.40)

0.973

1.13 (0.74–1.72)

0.564

1.15 (0.73–1.83)

0.548

DDS≥6 (N = 652)

0.57 (0.39–0.81)

0.002

0.67 (0.45–0.99)

0.042

0.7 (0.45–1.08)

0.104

Gender

The male low DDS group (N = 579)

0.58 (0.41–0.84)

0.003

0.64 (0.44–0.94)

0.021

0.62 (0.42–0.93)

0.027

The female low DDS group (N = 673)

0.52 (0.38–0.73)

<0.001

0.57 (0.40–0.80)

0.001

0.59 (0.41–0.85)

0.005

The male high DDS group (N = 559 )

0.74 (0.50–1.12)

0.152

0.90 (0.59–1.39)

0.644

0.98 (0.61–1.56)

0.945

The female High DDS group (N = 568 )

0.67 (0.47–0.96)

0.030

0.79 (0.54–1.15)

0.217

0.82 (0.55–1.23)

0.340

Low DDS group with age ≥ 80 (N = 830)

0.63 (0.48–0.84)

0.002

0.66 (0.50–0.89)

0.005

0.66 (0.48–0.90)

0.010

Low DDS group with age < 80 (N = 442)

0.42 (0.25–0.69)

0.001

0.43 (0.26–0.70)

0.001

0.43 (0.25–0.72)

0.002

High DDS group with age ≥ 80 (N = 652)

0.93 (0.67–1.28)

0.639

0.97 (0.7–1.35)

0.869

1.00 (0.70–1.42)

0.982

High DDS group with age < 80 (N = 475)

0.57 (0.33–0.98)

0.043

0.58 (0.33–1.00)

0.050

0.63 (1.13–2.93)

0.109