Table 3

Relationship between country of birth and rates of primary joint replacement in private and public hospitals

Primary joint replacement in private hospitals (n = 760)

Primary joint replacement in public hospitals (n = 249)

Heterogeneity of hazard ratios^a

Incidence rate (95% CI)^b

Hazard ratio (95% CI)^a

Incidence rate (95% CI)^b

Hazard ratio (95% CI)^a

P value

Australia

5.1 (4.7–5.5)

1.00 (reference)

1.2 (1.0–1.4)

1.00 (reference)

-

UK

3.6 (2.8–4.8)

0.76 (0.57–1.01)

1.7 (1.1–2.5)

1.50 (0.97–2.32)

0.01

Italy

1.7 (1.3–2.3)

0.24 (0.18–0.33)^c

1.7 (1.3–2.3)

0.99 (0.69–1.41)

< 0.0001

Greece

0.5 (0.3–0.9)

0.08 (0.04–0.14)^c

1.4 (1.0–2.1)

0.92 (0.61–1.39)

< 0.0001

Italy/Greece combined

1.1 (0.9–1.5)

0.17 (0.13–0.23)^c

1.6 (1.3–2.0)

0.96 (0.72–1.29)

< 0.0001

^aAdjusted for age, gender, body mass index, and education level. ^bPer 1,000 person-years. ^cStatistically significant, P < 0.001. CI, confidence interval.

Wang et al. Arthritis Research & Therapy 2009 11:R86   doi:10.1186/ar2721