Table 3 Cox proportional hazard model analysis for risk of RA.

H. pylori-infected group (ref: control)

1.45 (1.34–1.56)

< 0.0001

Index year

 2001–2005

Reference

 2006–2010

0.74 (0.67–0.81)

< 0.0001

 2011–2016

0.63 (0.54–0.74)

< 0.0001

Sex

 Female

Reference

 Male

0.44 (0.41–0.48)

< 0.0001

Age

 < 30

Reference

 30–44

2.24 (1.81–2.79)

< 0.0001

 45–64

3.77 (3.06–4.64)

< 0.0001

 ≥ 65

4.2 (3.35–5.28)

< 0.0001

Urbanization

 Urban

0.9 (0.82–0.99)

0.0246

 Sub-urban

Reference

 Rural

1.06 (0.91–1.24)

0.4325

Insurance property

 Government employee insurance

1.03 (0.89–1.18)

0.7329

 Labor insurance

Reference

 Farmer/fisherman/water resources employee insurance

0.91 (0.8–1.03)

0.1363

 Low-income family

1.26 (0.67–2.34)

0.4744

 Local insurance by government

1.08 (0.96–1.21)

0.1969

 Others

1.1 (0.82–1.48)

0.5406

Comorbidity (ref: without comorbidity)

 Hypertension

1.05 (0.96–1.16)

0.2960

 Diabetes mellitus

0.89 (0.78–1.01)

0.0756

 Hyperlipidemia

1.12 (1–1.25)

0.0528

 Asthma

1 (0.81–1.23)

0.9986

 Cerebrovascular disease

0.94 (0.77–1.14)

0.5331

 Chronic pulmonary diseases

1.24 (1.08–1.42)

0.0019

 Kidney disease

1.38 (1.14–1.67)

0.0009

 Liver disease

1.3 (1.18–1.43)

< 0.0001

 Pneumonia

1.38 (1.1–1.73)

0.0057

 Osteoporosis

1.38 (1.19–1.6)

< 0.0001

 Sjogren syndrome

2.15 (1.5–3.1)

< 0.0001

 Systemic lupus erythematosus

3.31 (1.95–5.64)

< 0.0001

 Ankylosing spondylitis

2.74 (1.86–4.04)

< 0.0001