Table 5.

Revision ratios (RRs) with 95% confidence intervals (CIs) for HRA devices compared to BHR. Data are based on a Cox regression model including implant design, sex, and femoral head diameter (categorized as ≤44 mm, 45–49 mm, 50–54 mm, and ≥55 mm). Age group, hospital volume (≥ 100 or <100 procedures) and diagnosis had no significant effect on adjustment (data not shown)

	RR	95% CI of RR	p-value
BHR (reference)	1.00
Cormet	1.05	0.59–1.87	0.9
ASR	3.96	3.20–4.91	< 0.001
ReCap	1.21	0.88–1.67	0.2
Durom	1.02	0.65–1.58	0.9
Conserve Plus	1.30	0.90–1.88	0.2
Female (male reference)	2.12	1.66–2.70	< 0.001
Femoral head diameter, mm
< 44 (reference)	1.00
45–49	0.70	0.54–0.92	0.01
50–54	0.61	0.44–0.85	0.003
≥ 55	0.46	0.27–0.77	0.003