Table 2.

Association between 2-year proximal migration and revision rate for aseptic loosening at 10 years ^a

	Increase in revision (%) / mm proximal migration	95% CI
Crude	10	5.5–14
Adjusted for b
N survival c	4.4	1.1–7.7
N RSA b	7.4	3.4–11
Survival study quality	11	6.2–15
RSA study quality	8.4	4.2–13
Total match score	5.8	2.2–9.4

^a The table shows the increase in the 10-year revision (%) for each 1-mm increase in 2-year proximal migration. In the crude analysis (unadjusted), 10% (95% CI: 5.5–14.2; p < 0.05) is added to the 10-year revision rate for every 1-mm increase in 2-year proximal migration.

^b When adjusted for, e.g., the number of hips in survival studies (N survival) 4.4% (95% CI: 1.1–7.7%; p < 0.05) is added to the 10-year revision rate for every 1-mm increase in 2-year proximal migration. The association between 2-year proximal migration and revision rate for aseptic loosening remains significant, when adjusting for confounders (all p-values < 0.05).

^c The square root of N was used for the weighted regression, so larger studies weighed more heavily.

N survival: number of cups in survival studies (survival study size);

N RSA: number of cups in RSA studies (RSA study size).