Table 3.

 Comparison of expected and observed incidence rates (%) of cancer at one year for patients with hip replacement (with 95% confidence intervals)

	Expected incidence rate*			Observed incidence rate
	Men	Women		Men	Women
All hip replacement	1.91 (1.82 to 2.00)	1.48 (1.42 to 1.54)		1.46 (1.39 to 1.54)	1.11 (1.06 to 1.16)
Stemmed metal-on-metal	1.45 (1.23 to 1.69)	1.22 (1.02 to 1.46)		1.15 (0.96 to 1.38)	0.84 (0.68 to 1.05)
Resurfacing	0.77 (0.63 to 0.94)	0.73 (0.54 to 0.98)		0.48 (0.37 to 0.62)	0.56 (0.40 to 0.78)
Other bearing surfaces	2.13 (2.05 to 2.22)	1.53 (1.47 to 1.59)		1.66 (1.57 to 1.76)	1.15 (1.10 to 1.21)

*Based on national incidence rates.