Table 4.

Risk of revision during 3 time periods according to major explanatory factors

Time period Variable	Category	RR	95% CI	p-value
1994–1999
Sex	Male	1
	Female	0.8	0.5–1.4	0.5
Age, years	19–69	1
	≥70	0.6	0.3–0.9	0.02
Diagnosis	OA	1
	RA	1.0	0.5–2.0	0.9
	AF	0.5	0.2–1.5	0.2
	FS	1.2	0.6–2.6	0.6
Prosthesis	HP	1
	ATP	4.5	2.3–9.0	< 0.001
	RP	1.2	0.5–2.8	0.7
	RTP	2.4	1.4–4.1	0.002
2000–2005
Sex	Male	1
	Female	0.9	0.6–1.5	0.8
Age, years	19–69	1
	≥70	0.45	0.3–0.7	0.001
Diagnosis	OA	1
	RA	0.7	0.4–1.2	0.2
	AF	0.4	0.2–0.8	0.008
	FS	1.3	0.8–2.2	0.3
Prosthesis	HP	1
	ATP	1.0	0.3–2.8	1.0
	RP	1.3	0.7–2.2	0.5
	RTP	1.2	0.6–2.2	0.6
2006–2012
Sex	Male	1
	Female	0.7	0.5–0.99	0.05
Age, years	19–69	1
	≥70	0.7	0.5–1.1	0.1
Diagnosis	OA	1
	RA	1.0	0.6–1.8	0.9
	AF	0.6	0.3–1.2	0.2
	FS	1.9	1.2–2.9	0.008
Prosthesis	HP	1
	ATP	1.0	0.5–1.9	1.0
	RP	2.4	1.4–4.1	0.001
	RTP	1.7	1.0–2.8	0.03

For abbreviations, see Table 3.